]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - kernel/trace/trace.c
ftrace: return an error when setting a nonexistent tracer
[linux-2.6-omap-h63xx.git] / kernel / trace / trace.c
index 8f3fb3db61c39306bdbffd36303cfed7dab02420..78d56614c95be41f14b44c7ce4a9f90015d6bb8f 100644 (file)
@@ -14,6 +14,7 @@
 #include <linux/utsrelease.h>
 #include <linux/kallsyms.h>
 #include <linux/seq_file.h>
+#include <linux/notifier.h>
 #include <linux/debugfs.h>
 #include <linux/pagemap.h>
 #include <linux/hardirq.h>
@@ -22,6 +23,7 @@
 #include <linux/ftrace.h>
 #include <linux/module.h>
 #include <linux/percpu.h>
+#include <linux/kdebug.h>
 #include <linux/ctype.h>
 #include <linux/init.h>
 #include <linux/poll.h>
 #include <linux/writeback.h>
 
 #include <linux/stacktrace.h>
+#include <linux/ring_buffer.h>
 
 #include "trace.h"
 
+#define TRACE_BUFFER_FLAGS     (RB_FL_OVERWRITE)
+
 unsigned long __read_mostly    tracing_max_latency = (cycle_t)ULONG_MAX;
 unsigned long __read_mostly    tracing_thresh;
 
-static unsigned long __read_mostly     tracing_nr_buffers;
+static DEFINE_PER_CPU(local_t, ftrace_cpu_disabled);
+
+static inline void ftrace_disable_cpu(void)
+{
+       preempt_disable();
+       local_inc(&__get_cpu_var(ftrace_cpu_disabled));
+}
+
+static inline void ftrace_enable_cpu(void)
+{
+       local_dec(&__get_cpu_var(ftrace_cpu_disabled));
+       preempt_enable();
+}
+
 static cpumask_t __read_mostly         tracing_buffer_mask;
 
 #define for_each_tracing_cpu(cpu)      \
        for_each_cpu_mask(cpu, tracing_buffer_mask)
 
-static int trace_alloc_page(void);
-static int trace_free_page(void);
-
 static int tracing_disabled = 1;
 
-static unsigned long tracing_pages_allocated;
-
 long
 ns2usecs(cycle_t nsec)
 {
@@ -60,7 +73,9 @@ ns2usecs(cycle_t nsec)
 
 cycle_t ftrace_now(int cpu)
 {
-       return cpu_clock(cpu);
+       u64 ts = ring_buffer_time_stamp(cpu);
+       ring_buffer_normalize_time_stamp(cpu, &ts);
+       return ts;
 }
 
 /*
@@ -100,11 +115,18 @@ static int                        tracer_enabled = 1;
 int                            ftrace_function_enabled;
 
 /*
- * trace_nr_entries is the number of entries that is allocated
- * for a buffer. Note, the number of entries is always rounded
- * to ENTRIES_PER_PAGE.
+ * trace_buf_size is the size in bytes that is allocated
+ * for a buffer. Note, the number of bytes is always rounded
+ * to page size.
+ *
+ * This number is purposely set to a low number of 16384.
+ * If the dump on oops happens, it will be much appreciated
+ * to not have to wait for all that output. Anyway this can be
+ * boot time and run time configurable.
  */
-static unsigned long           trace_nr_entries = 65536UL;
+#define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */
+
+static unsigned long           trace_buf_size = TRACE_BUF_SIZE_DEFAULT;
 
 /* trace_types holds a link list of available tracers. */
 static struct tracer           *trace_types __read_mostly;
@@ -133,24 +155,6 @@ static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
 /* trace_flags holds iter_ctrl options */
 unsigned long trace_flags = TRACE_ITER_PRINT_PARENT;
 
-static notrace void no_trace_init(struct trace_array *tr)
-{
-       int cpu;
-
-       ftrace_function_enabled = 0;
-       if(tr->ctrl)
-               for_each_online_cpu(cpu)
-                       tracing_reset(tr->data[cpu]);
-       tracer_enabled = 0;
-}
-
-/* dummy trace to disable tracing */
-static struct tracer no_tracer __read_mostly = {
-       .name           = "none",
-       .init           = no_trace_init
-};
-
-
 /**
  * trace_wake_up - wake up tasks waiting for trace input
  *
@@ -167,44 +171,27 @@ void trace_wake_up(void)
                wake_up(&trace_wait);
 }
 
-#define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry))
-
-static int __init set_nr_entries(char *str)
+static int __init set_buf_size(char *str)
 {
-       unsigned long nr_entries;
+       unsigned long buf_size;
        int ret;
 
        if (!str)
                return 0;
-       ret = strict_strtoul(str, 0, &nr_entries);
+       ret = strict_strtoul(str, 0, &buf_size);
        /* nr_entries can not be zero */
-       if (ret < 0 || nr_entries == 0)
+       if (ret < 0 || buf_size == 0)
                return 0;
-       trace_nr_entries = nr_entries;
+       trace_buf_size = buf_size;
        return 1;
 }
-__setup("trace_entries=", set_nr_entries);
+__setup("trace_buf_size=", set_buf_size);
 
 unsigned long nsecs_to_usecs(unsigned long nsecs)
 {
        return nsecs / 1000;
 }
 
-/*
- * trace_flag_type is an enumeration that holds different
- * states when a trace occurs. These are:
- *  IRQS_OFF   - interrupts were disabled
- *  NEED_RESCED - reschedule is requested
- *  HARDIRQ    - inside an interrupt handler
- *  SOFTIRQ    - inside a softirq handler
- */
-enum trace_flag_type {
-       TRACE_FLAG_IRQS_OFF             = 0x01,
-       TRACE_FLAG_NEED_RESCHED         = 0x02,
-       TRACE_FLAG_HARDIRQ              = 0x04,
-       TRACE_FLAG_SOFTIRQ              = 0x08,
-};
-
 /*
  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
  * control the output of kernel symbols.
@@ -224,6 +211,7 @@ static const char *trace_options[] = {
        "block",
        "stacktrace",
        "sched-tree",
+       "ftrace_printk",
        NULL
 };
 
@@ -266,54 +254,6 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
        tracing_record_cmdline(current);
 }
 
-#define CHECK_COND(cond)                       \
-       if (unlikely(cond)) {                   \
-               tracing_disabled = 1;           \
-               WARN_ON(1);                     \
-               return -1;                      \
-       }
-
-/**
- * check_pages - integrity check of trace buffers
- *
- * As a safty measure we check to make sure the data pages have not
- * been corrupted.
- */
-int check_pages(struct trace_array_cpu *data)
-{
-       struct page *page, *tmp;
-
-       CHECK_COND(data->trace_pages.next->prev != &data->trace_pages);
-       CHECK_COND(data->trace_pages.prev->next != &data->trace_pages);
-
-       list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) {
-               CHECK_COND(page->lru.next->prev != &page->lru);
-               CHECK_COND(page->lru.prev->next != &page->lru);
-       }
-
-       return 0;
-}
-
-/**
- * head_page - page address of the first page in per_cpu buffer.
- *
- * head_page returns the page address of the first page in
- * a per_cpu buffer. This also preforms various consistency
- * checks to make sure the buffer has not been corrupted.
- */
-void *head_page(struct trace_array_cpu *data)
-{
-       struct page *page;
-
-       if (list_empty(&data->trace_pages))
-               return NULL;
-
-       page = list_entry(data->trace_pages.next, struct page, lru);
-       BUG_ON(&page->lru == &data->trace_pages);
-
-       return page_address(page);
-}
-
 /**
  * trace_seq_printf - sequence printing of trace information
  * @s: trace sequence descriptor
@@ -460,34 +400,6 @@ trace_print_seq(struct seq_file *m, struct trace_seq *s)
        trace_seq_reset(s);
 }
 
-/*
- * flip the trace buffers between two trace descriptors.
- * This usually is the buffers between the global_trace and
- * the max_tr to record a snapshot of a current trace.
- *
- * The ftrace_max_lock must be held.
- */
-static void
-flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2)
-{
-       struct list_head flip_pages;
-
-       INIT_LIST_HEAD(&flip_pages);
-
-       memcpy(&tr1->trace_head_idx, &tr2->trace_head_idx,
-               sizeof(struct trace_array_cpu) -
-               offsetof(struct trace_array_cpu, trace_head_idx));
-
-       check_pages(tr1);
-       check_pages(tr2);
-       list_splice_init(&tr1->trace_pages, &flip_pages);
-       list_splice_init(&tr2->trace_pages, &tr1->trace_pages);
-       list_splice_init(&flip_pages, &tr2->trace_pages);
-       BUG_ON(!list_empty(&flip_pages));
-       check_pages(tr1);
-       check_pages(tr2);
-}
-
 /**
  * update_max_tr - snapshot all trace buffers from global_trace to max_tr
  * @tr: tracer
@@ -500,17 +412,17 @@ flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2)
 void
 update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 {
-       struct trace_array_cpu *data;
-       int i;
+       struct ring_buffer *buf = tr->buffer;
 
        WARN_ON_ONCE(!irqs_disabled());
        __raw_spin_lock(&ftrace_max_lock);
-       /* clear out all the previous traces */
-       for_each_tracing_cpu(i) {
-               data = tr->data[i];
-               flip_trace(max_tr.data[i], data);
-               tracing_reset(data);
-       }
+
+       tr->buffer = max_tr.buffer;
+       max_tr.buffer = buf;
+
+       ftrace_disable_cpu();
+       ring_buffer_reset(tr->buffer);
+       ftrace_enable_cpu();
 
        __update_max_tr(tr, tsk, cpu);
        __raw_spin_unlock(&ftrace_max_lock);
@@ -527,16 +439,19 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 void
 update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
 {
-       struct trace_array_cpu *data = tr->data[cpu];
-       int i;
+       int ret;
 
        WARN_ON_ONCE(!irqs_disabled());
        __raw_spin_lock(&ftrace_max_lock);
-       for_each_tracing_cpu(i)
-               tracing_reset(max_tr.data[i]);
 
-       flip_trace(max_tr.data[cpu], data);
-       tracing_reset(data);
+       ftrace_disable_cpu();
+
+       ring_buffer_reset(max_tr.buffer);
+       ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu);
+
+       ftrace_enable_cpu();
+
+       WARN_ON_ONCE(ret);
 
        __update_max_tr(tr, tsk, cpu);
        __raw_spin_unlock(&ftrace_max_lock);
@@ -573,7 +488,6 @@ int register_tracer(struct tracer *type)
 #ifdef CONFIG_FTRACE_STARTUP_TEST
        if (type->selftest) {
                struct tracer *saved_tracer = current_trace;
-               struct trace_array_cpu *data;
                struct trace_array *tr = &global_trace;
                int saved_ctrl = tr->ctrl;
                int i;
@@ -585,10 +499,7 @@ int register_tracer(struct tracer *type)
                 * If we fail, we do not register this tracer.
                 */
                for_each_tracing_cpu(i) {
-                       data = tr->data[i];
-                       if (!head_page(data))
-                               continue;
-                       tracing_reset(data);
+                       tracing_reset(tr, i);
                }
                current_trace = type;
                tr->ctrl = 0;
@@ -604,10 +515,7 @@ int register_tracer(struct tracer *type)
                }
                /* Only reset on passing, to avoid touching corrupted buffers */
                for_each_tracing_cpu(i) {
-                       data = tr->data[i];
-                       if (!head_page(data))
-                               continue;
-                       tracing_reset(data);
+                       tracing_reset(tr, i);
                }
                printk(KERN_CONT "PASSED\n");
        }
@@ -653,13 +561,11 @@ void unregister_tracer(struct tracer *type)
        mutex_unlock(&trace_types_lock);
 }
 
-void tracing_reset(struct trace_array_cpu *data)
+void tracing_reset(struct trace_array *tr, int cpu)
 {
-       data->trace_idx = 0;
-       data->overrun = 0;
-       data->trace_head = data->trace_tail = head_page(data);
-       data->trace_head_idx = 0;
-       data->trace_tail_idx = 0;
+       ftrace_disable_cpu();
+       ring_buffer_reset_cpu(tr->buffer, cpu);
+       ftrace_enable_cpu();
 }
 
 #define SAVED_CMDLINES 128
@@ -745,82 +651,16 @@ void tracing_record_cmdline(struct task_struct *tsk)
        trace_save_cmdline(tsk);
 }
 
-static inline struct list_head *
-trace_next_list(struct trace_array_cpu *data, struct list_head *next)
-{
-       /*
-        * Roundrobin - but skip the head (which is not a real page):
-        */
-       next = next->next;
-       if (unlikely(next == &data->trace_pages))
-               next = next->next;
-       BUG_ON(next == &data->trace_pages);
-
-       return next;
-}
-
-static inline void *
-trace_next_page(struct trace_array_cpu *data, void *addr)
-{
-       struct list_head *next;
-       struct page *page;
-
-       page = virt_to_page(addr);
-
-       next = trace_next_list(data, &page->lru);
-       page = list_entry(next, struct page, lru);
-
-       return page_address(page);
-}
-
-static inline struct trace_entry *
-tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data)
-{
-       unsigned long idx, idx_next;
-       struct trace_entry *entry;
-
-       data->trace_idx++;
-       idx = data->trace_head_idx;
-       idx_next = idx + 1;
-
-       BUG_ON(idx * TRACE_ENTRY_SIZE >= PAGE_SIZE);
-
-       entry = data->trace_head + idx * TRACE_ENTRY_SIZE;
-
-       if (unlikely(idx_next >= ENTRIES_PER_PAGE)) {
-               data->trace_head = trace_next_page(data, data->trace_head);
-               idx_next = 0;
-       }
-
-       if (data->trace_head == data->trace_tail &&
-           idx_next == data->trace_tail_idx) {
-               /* overrun */
-               data->overrun++;
-               data->trace_tail_idx++;
-               if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
-                       data->trace_tail =
-                               trace_next_page(data, data->trace_tail);
-                       data->trace_tail_idx = 0;
-               }
-       }
-
-       data->trace_head_idx = idx_next;
-
-       return entry;
-}
-
-static inline void
-tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
+void
+tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
+                            int pc)
 {
        struct task_struct *tsk = current;
-       unsigned long pc;
-
-       pc = preempt_count();
 
-       entry->preempt_count    = pc & 0xff;
-       entry->pid              = (tsk) ? tsk->pid : 0;
-       entry->t                = ftrace_now(raw_smp_processor_id());
-       entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
+       entry->preempt_count            = pc & 0xff;
+       entry->pid                      = (tsk) ? tsk->pid : 0;
+       entry->flags =
+               (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
                ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
                ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
                (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
@@ -828,145 +668,139 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
 
 void
 trace_function(struct trace_array *tr, struct trace_array_cpu *data,
-              unsigned long ip, unsigned long parent_ip, unsigned long flags)
+              unsigned long ip, unsigned long parent_ip, unsigned long flags,
+              int pc)
 {
-       struct trace_entry *entry;
+       struct ring_buffer_event *event;
+       struct ftrace_entry *entry;
        unsigned long irq_flags;
 
-       raw_local_irq_save(irq_flags);
-       __raw_spin_lock(&data->lock);
-       entry                   = tracing_get_trace_entry(tr, data);
-       tracing_generic_entry_update(entry, flags);
-       entry->type             = TRACE_FN;
-       entry->fn.ip            = ip;
-       entry->fn.parent_ip     = parent_ip;
-       __raw_spin_unlock(&data->lock);
-       raw_local_irq_restore(irq_flags);
+       /* If we are reading the ring buffer, don't trace */
+       if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+               return;
+
+       event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+                                        &irq_flags);
+       if (!event)
+               return;
+       entry   = ring_buffer_event_data(event);
+       tracing_generic_entry_update(&entry->ent, flags, pc);
+       entry->ent.type                 = TRACE_FN;
+       entry->ip                       = ip;
+       entry->parent_ip                = parent_ip;
+       ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
 }
 
 void
 ftrace(struct trace_array *tr, struct trace_array_cpu *data,
-       unsigned long ip, unsigned long parent_ip, unsigned long flags)
+       unsigned long ip, unsigned long parent_ip, unsigned long flags,
+       int pc)
 {
        if (likely(!atomic_read(&data->disabled)))
-               trace_function(tr, data, ip, parent_ip, flags);
+               trace_function(tr, data, ip, parent_ip, flags, pc);
 }
 
-#ifdef CONFIG_MMIOTRACE
-void __trace_mmiotrace_rw(struct trace_array *tr, struct trace_array_cpu *data,
-                                               struct mmiotrace_rw *rw)
+static void ftrace_trace_stack(struct trace_array *tr,
+                              struct trace_array_cpu *data,
+                              unsigned long flags,
+                              int skip, int pc)
 {
-       struct trace_entry *entry;
+       struct ring_buffer_event *event;
+       struct stack_entry *entry;
+       struct stack_trace trace;
        unsigned long irq_flags;
 
-       raw_local_irq_save(irq_flags);
-       __raw_spin_lock(&data->lock);
-
-       entry                   = tracing_get_trace_entry(tr, data);
-       tracing_generic_entry_update(entry, 0);
-       entry->type             = TRACE_MMIO_RW;
-       entry->mmiorw           = *rw;
-
-       __raw_spin_unlock(&data->lock);
-       raw_local_irq_restore(irq_flags);
-
-       trace_wake_up();
-}
-
-void __trace_mmiotrace_map(struct trace_array *tr, struct trace_array_cpu *data,
-                                               struct mmiotrace_map *map)
-{
-       struct trace_entry *entry;
-       unsigned long irq_flags;
+       if (!(trace_flags & TRACE_ITER_STACKTRACE))
+               return;
 
-       raw_local_irq_save(irq_flags);
-       __raw_spin_lock(&data->lock);
+       event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+                                        &irq_flags);
+       if (!event)
+               return;
+       entry   = ring_buffer_event_data(event);
+       tracing_generic_entry_update(&entry->ent, flags, pc);
+       entry->ent.type         = TRACE_STACK;
 
-       entry                   = tracing_get_trace_entry(tr, data);
-       tracing_generic_entry_update(entry, 0);
-       entry->type             = TRACE_MMIO_MAP;
-       entry->mmiomap          = *map;
+       memset(&entry->caller, 0, sizeof(entry->caller));
 
-       __raw_spin_unlock(&data->lock);
-       raw_local_irq_restore(irq_flags);
+       trace.nr_entries        = 0;
+       trace.max_entries       = FTRACE_STACK_ENTRIES;
+       trace.skip              = skip;
+       trace.entries           = entry->caller;
 
-       trace_wake_up();
+       save_stack_trace(&trace);
+       ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
 }
-#endif
 
 void __trace_stack(struct trace_array *tr,
                   struct trace_array_cpu *data,
                   unsigned long flags,
                   int skip)
 {
-       struct trace_entry *entry;
-       struct stack_trace trace;
-
-       if (!(trace_flags & TRACE_ITER_STACKTRACE))
-               return;
-
-       entry                   = tracing_get_trace_entry(tr, data);
-       tracing_generic_entry_update(entry, flags);
-       entry->type             = TRACE_STACK;
-
-       memset(&entry->stack, 0, sizeof(entry->stack));
-
-       trace.nr_entries        = 0;
-       trace.max_entries       = FTRACE_STACK_ENTRIES;
-       trace.skip              = skip;
-       trace.entries           = entry->stack.caller;
-
-       save_stack_trace(&trace);
+       ftrace_trace_stack(tr, data, flags, skip, preempt_count());
 }
 
-void
-__trace_special(void *__tr, void *__data,
-               unsigned long arg1, unsigned long arg2, unsigned long arg3)
+static void
+ftrace_trace_special(void *__tr, void *__data,
+                    unsigned long arg1, unsigned long arg2, unsigned long arg3,
+                    int pc)
 {
+       struct ring_buffer_event *event;
        struct trace_array_cpu *data = __data;
        struct trace_array *tr = __tr;
-       struct trace_entry *entry;
+       struct special_entry *entry;
        unsigned long irq_flags;
 
-       raw_local_irq_save(irq_flags);
-       __raw_spin_lock(&data->lock);
-       entry                   = tracing_get_trace_entry(tr, data);
-       tracing_generic_entry_update(entry, 0);
-       entry->type             = TRACE_SPECIAL;
-       entry->special.arg1     = arg1;
-       entry->special.arg2     = arg2;
-       entry->special.arg3     = arg3;
-       __trace_stack(tr, data, irq_flags, 4);
-       __raw_spin_unlock(&data->lock);
-       raw_local_irq_restore(irq_flags);
+       event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+                                        &irq_flags);
+       if (!event)
+               return;
+       entry   = ring_buffer_event_data(event);
+       tracing_generic_entry_update(&entry->ent, 0, pc);
+       entry->ent.type                 = TRACE_SPECIAL;
+       entry->arg1                     = arg1;
+       entry->arg2                     = arg2;
+       entry->arg3                     = arg3;
+       ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+       ftrace_trace_stack(tr, data, irq_flags, 4, pc);
 
        trace_wake_up();
 }
 
+void
+__trace_special(void *__tr, void *__data,
+               unsigned long arg1, unsigned long arg2, unsigned long arg3)
+{
+       ftrace_trace_special(__tr, __data, arg1, arg2, arg3, preempt_count());
+}
+
 void
 tracing_sched_switch_trace(struct trace_array *tr,
                           struct trace_array_cpu *data,
                           struct task_struct *prev,
                           struct task_struct *next,
-                          unsigned long flags)
+                          unsigned long flags, int pc)
 {
-       struct trace_entry *entry;
+       struct ring_buffer_event *event;
+       struct ctx_switch_entry *entry;
        unsigned long irq_flags;
 
-       raw_local_irq_save(irq_flags);
-       __raw_spin_lock(&data->lock);
-       entry                   = tracing_get_trace_entry(tr, data);
-       tracing_generic_entry_update(entry, flags);
-       entry->type             = TRACE_CTX;
-       entry->ctx.prev_pid     = prev->pid;
-       entry->ctx.prev_prio    = prev->prio;
-       entry->ctx.prev_state   = prev->state;
-       entry->ctx.next_pid     = next->pid;
-       entry->ctx.next_prio    = next->prio;
-       entry->ctx.next_state   = next->state;
-       __trace_stack(tr, data, flags, 5);
-       __raw_spin_unlock(&data->lock);
-       raw_local_irq_restore(irq_flags);
+       event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+                                          &irq_flags);
+       if (!event)
+               return;
+       entry   = ring_buffer_event_data(event);
+       tracing_generic_entry_update(&entry->ent, flags, pc);
+       entry->ent.type                 = TRACE_CTX;
+       entry->prev_pid                 = prev->pid;
+       entry->prev_prio                = prev->prio;
+       entry->prev_state               = prev->state;
+       entry->next_pid                 = next->pid;
+       entry->next_prio                = next->prio;
+       entry->next_state               = next->state;
+       entry->next_cpu = task_cpu(next);
+       ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+       ftrace_trace_stack(tr, data, flags, 5, pc);
 }
 
 void
@@ -974,25 +808,28 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
                           struct trace_array_cpu *data,
                           struct task_struct *wakee,
                           struct task_struct *curr,
-                          unsigned long flags)
+                          unsigned long flags, int pc)
 {
-       struct trace_entry *entry;
+       struct ring_buffer_event *event;
+       struct ctx_switch_entry *entry;
        unsigned long irq_flags;
 
-       raw_local_irq_save(irq_flags);
-       __raw_spin_lock(&data->lock);
-       entry                   = tracing_get_trace_entry(tr, data);
-       tracing_generic_entry_update(entry, flags);
-       entry->type             = TRACE_WAKE;
-       entry->ctx.prev_pid     = curr->pid;
-       entry->ctx.prev_prio    = curr->prio;
-       entry->ctx.prev_state   = curr->state;
-       entry->ctx.next_pid     = wakee->pid;
-       entry->ctx.next_prio    = wakee->prio;
-       entry->ctx.next_state   = wakee->state;
-       __trace_stack(tr, data, flags, 6);
-       __raw_spin_unlock(&data->lock);
-       raw_local_irq_restore(irq_flags);
+       event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+                                          &irq_flags);
+       if (!event)
+               return;
+       entry   = ring_buffer_event_data(event);
+       tracing_generic_entry_update(&entry->ent, flags, pc);
+       entry->ent.type                 = TRACE_WAKE;
+       entry->prev_pid                 = curr->pid;
+       entry->prev_prio                = curr->prio;
+       entry->prev_state               = curr->state;
+       entry->next_pid                 = wakee->pid;
+       entry->next_prio                = wakee->prio;
+       entry->next_state               = wakee->state;
+       entry->next_cpu                 = task_cpu(wakee);
+       ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+       ftrace_trace_stack(tr, data, flags, 6, pc);
 
        trace_wake_up();
 }
@@ -1002,23 +839,21 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
 {
        struct trace_array *tr = &global_trace;
        struct trace_array_cpu *data;
-       unsigned long flags;
-       long disabled;
        int cpu;
+       int pc;
 
-       if (tracing_disabled || current_trace == &no_tracer || !tr->ctrl)
+       if (tracing_disabled || !tr->ctrl)
                return;
 
-       local_irq_save(flags);
+       pc = preempt_count();
+       preempt_disable_notrace();
        cpu = raw_smp_processor_id();
        data = tr->data[cpu];
-       disabled = atomic_inc_return(&data->disabled);
 
-       if (likely(disabled == 1))
-               __trace_special(tr, data, arg1, arg2, arg3);
+       if (likely(!atomic_read(&data->disabled)))
+               ftrace_trace_special(tr, data, arg1, arg2, arg3, pc);
 
-       atomic_dec(&data->disabled);
-       local_irq_restore(flags);
+       preempt_enable_notrace();
 }
 
 #ifdef CONFIG_FTRACE
@@ -1029,7 +864,8 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
        struct trace_array_cpu *data;
        unsigned long flags;
        long disabled;
-       int cpu;
+       int cpu, resched;
+       int pc;
 
        if (unlikely(!ftrace_function_enabled))
                return;
@@ -1037,16 +873,22 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
        if (skip_trace(ip))
                return;
 
-       local_irq_save(flags);
+       pc = preempt_count();
+       resched = need_resched();
+       preempt_disable_notrace();
+       local_save_flags(flags);
        cpu = raw_smp_processor_id();
        data = tr->data[cpu];
        disabled = atomic_inc_return(&data->disabled);
 
        if (likely(disabled == 1))
-               trace_function(tr, data, ip, parent_ip, flags);
+               trace_function(tr, data, ip, parent_ip, flags, pc);
 
        atomic_dec(&data->disabled);
-       local_irq_restore(flags);
+       if (resched)
+               preempt_enable_no_resched_notrace();
+       else
+               preempt_enable_notrace();
 }
 
 static struct ftrace_ops trace_ops __read_mostly =
@@ -1073,111 +915,96 @@ enum trace_file_type {
        TRACE_FILE_LAT_FMT      = 1,
 };
 
-static struct trace_entry *
-trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data,
-               struct trace_iterator *iter, int cpu)
+static void trace_iterator_increment(struct trace_iterator *iter, int cpu)
 {
-       struct page *page;
-       struct trace_entry *array;
+       /* Don't allow ftrace to trace into the ring buffers */
+       ftrace_disable_cpu();
 
-       if (iter->next_idx[cpu] >= tr->entries ||
-           iter->next_idx[cpu] >= data->trace_idx ||
-           (data->trace_head == data->trace_tail &&
-            data->trace_head_idx == data->trace_tail_idx))
-               return NULL;
+       iter->idx++;
+       if (iter->buffer_iter[iter->cpu])
+               ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
 
-       if (!iter->next_page[cpu]) {
-               /* Initialize the iterator for this cpu trace buffer */
-               WARN_ON(!data->trace_tail);
-               page = virt_to_page(data->trace_tail);
-               iter->next_page[cpu] = &page->lru;
-               iter->next_page_idx[cpu] = data->trace_tail_idx;
-       }
+       ftrace_enable_cpu();
+}
+
+static struct trace_entry *
+peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts)
+{
+       struct ring_buffer_event *event;
+       struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu];
 
-       page = list_entry(iter->next_page[cpu], struct page, lru);
-       BUG_ON(&data->trace_pages == &page->lru);
+       /* Don't allow ftrace to trace into the ring buffers */
+       ftrace_disable_cpu();
 
-       array = page_address(page);
+       if (buf_iter)
+               event = ring_buffer_iter_peek(buf_iter, ts);
+       else
+               event = ring_buffer_peek(iter->tr->buffer, cpu, ts);
+
+       ftrace_enable_cpu();
 
-       WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE);
-       return &array[iter->next_page_idx[cpu]];
+       return event ? ring_buffer_event_data(event) : NULL;
 }
 
 static struct trace_entry *
-find_next_entry(struct trace_iterator *iter, int *ent_cpu)
+__find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts)
 {
-       struct trace_array *tr = iter->tr;
+       struct ring_buffer *buffer = iter->tr->buffer;
        struct trace_entry *ent, *next = NULL;
+       u64 next_ts = 0, ts;
        int next_cpu = -1;
        int cpu;
 
        for_each_tracing_cpu(cpu) {
-               if (!head_page(tr->data[cpu]))
+
+               if (ring_buffer_empty_cpu(buffer, cpu))
                        continue;
-               ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu);
+
+               ent = peek_next_entry(iter, cpu, &ts);
+
                /*
                 * Pick the entry with the smallest timestamp:
                 */
-               if (ent && (!next || ent->t < next->t)) {
+               if (ent && (!next || ts < next_ts)) {
                        next = ent;
                        next_cpu = cpu;
+                       next_ts = ts;
                }
        }
 
        if (ent_cpu)
                *ent_cpu = next_cpu;
 
+       if (ent_ts)
+               *ent_ts = next_ts;
+
        return next;
 }
 
-static void trace_iterator_increment(struct trace_iterator *iter)
+/* Find the next real entry, without updating the iterator itself */
+static struct trace_entry *
+find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts)
 {
-       iter->idx++;
-       iter->next_idx[iter->cpu]++;
-       iter->next_page_idx[iter->cpu]++;
-
-       if (iter->next_page_idx[iter->cpu] >= ENTRIES_PER_PAGE) {
-               struct trace_array_cpu *data = iter->tr->data[iter->cpu];
-
-               iter->next_page_idx[iter->cpu] = 0;
-               iter->next_page[iter->cpu] =
-                       trace_next_list(data, iter->next_page[iter->cpu]);
-       }
+       return __find_next_entry(iter, ent_cpu, ent_ts);
 }
 
-static void trace_consume(struct trace_iterator *iter)
+/* Find the next real entry, and increment the iterator to the next entry */
+static void *find_next_entry_inc(struct trace_iterator *iter)
 {
-       struct trace_array_cpu *data = iter->tr->data[iter->cpu];
+       iter->ent = __find_next_entry(iter, &iter->cpu, &iter->ts);
 
-       data->trace_tail_idx++;
-       if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
-               data->trace_tail = trace_next_page(data, data->trace_tail);
-               data->trace_tail_idx = 0;
-       }
+       if (iter->ent)
+               trace_iterator_increment(iter, iter->cpu);
 
-       /* Check if we empty it, then reset the index */
-       if (data->trace_head == data->trace_tail &&
-           data->trace_head_idx == data->trace_tail_idx)
-               data->trace_idx = 0;
+       return iter->ent ? iter : NULL;
 }
 
-static void *find_next_entry_inc(struct trace_iterator *iter)
+static void trace_consume(struct trace_iterator *iter)
 {
-       struct trace_entry *next;
-       int next_cpu = -1;
-
-       next = find_next_entry(iter, &next_cpu);
-
-       iter->prev_ent = iter->ent;
-       iter->prev_cpu = iter->cpu;
-
-       iter->ent = next;
-       iter->cpu = next_cpu;
-
-       if (next)
-               trace_iterator_increment(iter);
-
-       return next ? iter : NULL;
+       /* Don't allow ftrace to trace into the ring buffers */
+       ftrace_disable_cpu();
+       ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts);
+       ftrace_enable_cpu();
 }
 
 static void *s_next(struct seq_file *m, void *v, loff_t *pos)
@@ -1210,7 +1037,7 @@ static void *s_start(struct seq_file *m, loff_t *pos)
        struct trace_iterator *iter = m->private;
        void *p = NULL;
        loff_t l = 0;
-       int i;
+       int cpu;
 
        mutex_lock(&trace_types_lock);
 
@@ -1229,14 +1056,15 @@ static void *s_start(struct seq_file *m, loff_t *pos)
                iter->ent = NULL;
                iter->cpu = 0;
                iter->idx = -1;
-               iter->prev_ent = NULL;
-               iter->prev_cpu = -1;
 
-               for_each_tracing_cpu(i) {
-                       iter->next_idx[i] = 0;
-                       iter->next_page[i] = NULL;
+               ftrace_disable_cpu();
+
+               for_each_tracing_cpu(cpu) {
+                       ring_buffer_iter_reset(iter->buffer_iter[cpu]);
                }
 
+               ftrace_enable_cpu();
+
                for (p = iter; p && l < *pos; p = s_next(m, p, &l))
                        ;
 
@@ -1330,21 +1158,21 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 
 static void print_lat_help_header(struct seq_file *m)
 {
-       seq_puts(m, "#                _------=> CPU#            \n");
-       seq_puts(m, "#               / _-----=> irqs-off        \n");
-       seq_puts(m, "#              | / _----=> need-resched    \n");
-       seq_puts(m, "#              || / _---=> hardirq/softirq \n");
-       seq_puts(m, "#              ||| / _--=> preempt-depth   \n");
-       seq_puts(m, "#              |||| /                      \n");
-       seq_puts(m, "#              |||||     delay             \n");
-       seq_puts(m, "#  cmd     pid ||||| time  |   caller      \n");
-       seq_puts(m, "#     \\   /    |||||   \\   |   /           \n");
+       seq_puts(m, "#                  _------=> CPU#            \n");
+       seq_puts(m, "#                 / _-----=> irqs-off        \n");
+       seq_puts(m, "#                | / _----=> need-resched    \n");
+       seq_puts(m, "#                || / _---=> hardirq/softirq \n");
+       seq_puts(m, "#                ||| / _--=> preempt-depth   \n");
+       seq_puts(m, "#                |||| /                      \n");
+       seq_puts(m, "#                |||||     delay             \n");
+       seq_puts(m, "#  cmd     pid   ||||| time  |   caller      \n");
+       seq_puts(m, "#     \\   /      |||||   \\   |   /           \n");
 }
 
 static void print_func_help_header(struct seq_file *m)
 {
-       seq_puts(m, "#           TASK-PID   CPU#    TIMESTAMP  FUNCTION\n");
-       seq_puts(m, "#              | |      |          |         |\n");
+       seq_puts(m, "#           TASK-PID    CPU#    TIMESTAMP  FUNCTION\n");
+       seq_puts(m, "#              | |       |          |         |\n");
 }
 
 
@@ -1355,23 +1183,16 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
        struct trace_array *tr = iter->tr;
        struct trace_array_cpu *data = tr->data[tr->cpu];
        struct tracer *type = current_trace;
-       unsigned long total   = 0;
-       unsigned long entries = 0;
-       int cpu;
+       unsigned long total;
+       unsigned long entries;
        const char *name = "preemption";
 
        if (type)
                name = type->name;
 
-       for_each_tracing_cpu(cpu) {
-               if (head_page(tr->data[cpu])) {
-                       total += tr->data[cpu]->trace_idx;
-                       if (tr->data[cpu]->trace_idx > tr->entries)
-                               entries += tr->entries;
-                       else
-                               entries += tr->data[cpu]->trace_idx;
-               }
-       }
+       entries = ring_buffer_entries(iter->tr->buffer);
+       total = entries +
+               ring_buffer_overruns(iter->tr->buffer);
 
        seq_printf(m, "%s latency trace v1.1.5 on %s\n",
                   name, UTS_RELEASE);
@@ -1428,7 +1249,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
        comm = trace_find_cmdline(entry->pid);
 
        trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid);
-       trace_seq_printf(s, "%d", cpu);
+       trace_seq_printf(s, "%3d", cpu);
        trace_seq_printf(s, "%c%c",
                        (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.',
                        ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
@@ -1457,7 +1278,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 unsigned long preempt_mark_thresh = 100;
 
 static void
-lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs,
+lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
                    unsigned long rel_usecs)
 {
        trace_seq_printf(s, " %4lldus", abs_usecs);
@@ -1471,34 +1292,76 @@ lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs,
 
 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 
-static int
+/*
+ * The message is supposed to contain an ending newline.
+ * If the printing stops prematurely, try to add a newline of our own.
+ */
+void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter)
+{
+       struct trace_entry *ent;
+       struct trace_field_cont *cont;
+       bool ok = true;
+
+       ent = peek_next_entry(iter, iter->cpu, NULL);
+       if (!ent || ent->type != TRACE_CONT) {
+               trace_seq_putc(s, '\n');
+               return;
+       }
+
+       do {
+               cont = (struct trace_field_cont *)ent;
+               if (ok)
+                       ok = (trace_seq_printf(s, "%s", cont->buf) > 0);
+
+               ftrace_disable_cpu();
+
+               if (iter->buffer_iter[iter->cpu])
+                       ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
+               else
+                       ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL);
+
+               ftrace_enable_cpu();
+
+               ent = peek_next_entry(iter, iter->cpu, NULL);
+       } while (ent && ent->type == TRACE_CONT);
+
+       if (!ok)
+               trace_seq_putc(s, '\n');
+}
+
+static enum print_line_t
 print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 {
        struct trace_seq *s = &iter->seq;
        unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
-       struct trace_entry *next_entry = find_next_entry(iter, NULL);
+       struct trace_entry *next_entry;
        unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
        struct trace_entry *entry = iter->ent;
        unsigned long abs_usecs;
        unsigned long rel_usecs;
+       u64 next_ts;
        char *comm;
        int S, T;
        int i;
        unsigned state;
 
+       if (entry->type == TRACE_CONT)
+               return TRACE_TYPE_HANDLED;
+
+       next_entry = find_next_entry(iter, NULL, &next_ts);
        if (!next_entry)
-               next_entry = entry;
-       rel_usecs = ns2usecs(next_entry->t - entry->t);
-       abs_usecs = ns2usecs(entry->t - iter->tr->time_start);
+               next_ts = iter->ts;
+       rel_usecs = ns2usecs(next_ts - iter->ts);
+       abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
 
        if (verbose) {
                comm = trace_find_cmdline(entry->pid);
-               trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]"
+               trace_seq_printf(s, "%16s %5d %3d %d %08x %08x [%08lx]"
                                 " %ld.%03ldms (+%ld.%03ldms): ",
                                 comm,
                                 entry->pid, cpu, entry->flags,
                                 entry->preempt_count, trace_idx,
-                                ns2usecs(entry->t),
+                                ns2usecs(iter->ts),
                                 abs_usecs/1000,
                                 abs_usecs % 1000, rel_usecs/1000,
                                 rel_usecs % 1000);
@@ -1507,52 +1370,85 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
                lat_print_timestamp(s, abs_usecs, rel_usecs);
        }
        switch (entry->type) {
-       case TRACE_FN:
-               seq_print_ip_sym(s, entry->fn.ip, sym_flags);
+       case TRACE_FN: {
+               struct ftrace_entry *field;
+
+               trace_assign_type(field, entry);
+
+               seq_print_ip_sym(s, field->ip, sym_flags);
                trace_seq_puts(s, " (");
-               if (kretprobed(entry->fn.parent_ip))
+               if (kretprobed(field->parent_ip))
                        trace_seq_puts(s, KRETPROBE_MSG);
                else
-                       seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags);
+                       seq_print_ip_sym(s, field->parent_ip, sym_flags);
                trace_seq_puts(s, ")\n");
                break;
+       }
        case TRACE_CTX:
-       case TRACE_WAKE:
-               T = entry->ctx.next_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.next_state] : 'X';
+       case TRACE_WAKE: {
+               struct ctx_switch_entry *field;
+
+               trace_assign_type(field, entry);
 
-               state = entry->ctx.prev_state ? __ffs(entry->ctx.prev_state) + 1 : 0;
+               T = field->next_state < sizeof(state_to_char) ?
+                       state_to_char[field->next_state] : 'X';
+
+               state = field->prev_state ?
+                       __ffs(field->prev_state) + 1 : 0;
                S = state < sizeof(state_to_char) - 1 ? state_to_char[state] : 'X';
-               comm = trace_find_cmdline(entry->ctx.next_pid);
-               trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c %s\n",
-                                entry->ctx.prev_pid,
-                                entry->ctx.prev_prio,
+               comm = trace_find_cmdline(field->next_pid);
+               trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
+                                field->prev_pid,
+                                field->prev_prio,
                                 S, entry->type == TRACE_CTX ? "==>" : "  +",
-                                entry->ctx.next_pid,
-                                entry->ctx.next_prio,
+                                field->next_cpu,
+                                field->next_pid,
+                                field->next_prio,
                                 T, comm);
                break;
-       case TRACE_SPECIAL:
+       }
+       case TRACE_SPECIAL: {
+               struct special_entry *field;
+
+               trace_assign_type(field, entry);
+
                trace_seq_printf(s, "# %ld %ld %ld\n",
-                                entry->special.arg1,
-                                entry->special.arg2,
-                                entry->special.arg3);
+                                field->arg1,
+                                field->arg2,
+                                field->arg3);
                break;
-       case TRACE_STACK:
+       }
+       case TRACE_STACK: {
+               struct stack_entry *field;
+
+               trace_assign_type(field, entry);
+
                for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
                        if (i)
                                trace_seq_puts(s, " <= ");
-                       seq_print_ip_sym(s, entry->stack.caller[i], sym_flags);
+                       seq_print_ip_sym(s, field->caller[i], sym_flags);
                }
                trace_seq_puts(s, "\n");
                break;
+       }
+       case TRACE_PRINT: {
+               struct print_entry *field;
+
+               trace_assign_type(field, entry);
+
+               seq_print_ip_sym(s, field->ip, sym_flags);
+               trace_seq_printf(s, ": %s", field->buf);
+               if (entry->flags & TRACE_FLAG_CONT)
+                       trace_seq_print_cont(s, iter);
+               break;
+       }
        default:
                trace_seq_printf(s, "Unknown type %d\n", entry->type);
        }
-       return 1;
+       return TRACE_TYPE_HANDLED;
 }
 
-static int print_trace_fmt(struct trace_iterator *iter)
+static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
 {
        struct trace_seq *s = &iter->seq;
        unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
@@ -1567,90 +1463,126 @@ static int print_trace_fmt(struct trace_iterator *iter)
 
        entry = iter->ent;
 
+       if (entry->type == TRACE_CONT)
+               return TRACE_TYPE_HANDLED;
+
        comm = trace_find_cmdline(iter->ent->pid);
 
-       t = ns2usecs(entry->t);
+       t = ns2usecs(iter->ts);
        usec_rem = do_div(t, 1000000ULL);
        secs = (unsigned long)t;
 
        ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
        if (!ret)
-               return 0;
-       ret = trace_seq_printf(s, "[%02d] ", iter->cpu);
+               return TRACE_TYPE_PARTIAL_LINE;
+       ret = trace_seq_printf(s, "[%03d] ", iter->cpu);
        if (!ret)
-               return 0;
+               return TRACE_TYPE_PARTIAL_LINE;
        ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
        if (!ret)
-               return 0;
+               return TRACE_TYPE_PARTIAL_LINE;
 
        switch (entry->type) {
-       case TRACE_FN:
-               ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags);
+       case TRACE_FN: {
+               struct ftrace_entry *field;
+
+               trace_assign_type(field, entry);
+
+               ret = seq_print_ip_sym(s, field->ip, sym_flags);
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
-                                               entry->fn.parent_ip) {
+                                               field->parent_ip) {
                        ret = trace_seq_printf(s, " <-");
                        if (!ret)
-                               return 0;
-                       if (kretprobed(entry->fn.parent_ip))
+                               return TRACE_TYPE_PARTIAL_LINE;
+                       if (kretprobed(field->parent_ip))
                                ret = trace_seq_puts(s, KRETPROBE_MSG);
                        else
-                               ret = seq_print_ip_sym(s, entry->fn.parent_ip,
+                               ret = seq_print_ip_sym(s,
+                                                      field->parent_ip,
                                                       sym_flags);
                        if (!ret)
-                               return 0;
+                               return TRACE_TYPE_PARTIAL_LINE;
                }
                ret = trace_seq_printf(s, "\n");
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                break;
+       }
        case TRACE_CTX:
-       case TRACE_WAKE:
-               S = entry->ctx.prev_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.prev_state] : 'X';
-               T = entry->ctx.next_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.next_state] : 'X';
-               ret = trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c\n",
-                                      entry->ctx.prev_pid,
-                                      entry->ctx.prev_prio,
+       case TRACE_WAKE: {
+               struct ctx_switch_entry *field;
+
+               trace_assign_type(field, entry);
+
+               S = field->prev_state < sizeof(state_to_char) ?
+                       state_to_char[field->prev_state] : 'X';
+               T = field->next_state < sizeof(state_to_char) ?
+                       state_to_char[field->next_state] : 'X';
+               ret = trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c\n",
+                                      field->prev_pid,
+                                      field->prev_prio,
                                       S,
                                       entry->type == TRACE_CTX ? "==>" : "  +",
-                                      entry->ctx.next_pid,
-                                      entry->ctx.next_prio,
+                                      field->next_cpu,
+                                      field->next_pid,
+                                      field->next_prio,
                                       T);
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                break;
-       case TRACE_SPECIAL:
+       }
+       case TRACE_SPECIAL: {
+               struct special_entry *field;
+
+               trace_assign_type(field, entry);
+
                ret = trace_seq_printf(s, "# %ld %ld %ld\n",
-                                entry->special.arg1,
-                                entry->special.arg2,
-                                entry->special.arg3);
+                                field->arg1,
+                                field->arg2,
+                                field->arg3);
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                break;
-       case TRACE_STACK:
+       }
+       case TRACE_STACK: {
+               struct stack_entry *field;
+
+               trace_assign_type(field, entry);
+
                for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
                        if (i) {
                                ret = trace_seq_puts(s, " <= ");
                                if (!ret)
-                                       return 0;
+                                       return TRACE_TYPE_PARTIAL_LINE;
                        }
-                       ret = seq_print_ip_sym(s, entry->stack.caller[i],
+                       ret = seq_print_ip_sym(s, field->caller[i],
                                               sym_flags);
                        if (!ret)
-                               return 0;
+                               return TRACE_TYPE_PARTIAL_LINE;
                }
                ret = trace_seq_puts(s, "\n");
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                break;
        }
-       return 1;
+       case TRACE_PRINT: {
+               struct print_entry *field;
+
+               trace_assign_type(field, entry);
+
+               seq_print_ip_sym(s, field->ip, sym_flags);
+               trace_seq_printf(s, ": %s", field->buf);
+               if (entry->flags & TRACE_FLAG_CONT)
+                       trace_seq_print_cont(s, iter);
+               break;
+       }
+       }
+       return TRACE_TYPE_HANDLED;
 }
 
-static int print_raw_fmt(struct trace_iterator *iter)
+static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
 {
        struct trace_seq *s = &iter->seq;
        struct trace_entry *entry;
@@ -1659,47 +1591,77 @@ static int print_raw_fmt(struct trace_iterator *iter)
 
        entry = iter->ent;
 
+       if (entry->type == TRACE_CONT)
+               return TRACE_TYPE_HANDLED;
+
        ret = trace_seq_printf(s, "%d %d %llu ",
-               entry->pid, iter->cpu, entry->t);
+               entry->pid, iter->cpu, iter->ts);
        if (!ret)
-               return 0;
+               return TRACE_TYPE_PARTIAL_LINE;
 
        switch (entry->type) {
-       case TRACE_FN:
+       case TRACE_FN: {
+               struct ftrace_entry *field;
+
+               trace_assign_type(field, entry);
+
                ret = trace_seq_printf(s, "%x %x\n",
-                                       entry->fn.ip, entry->fn.parent_ip);
+                                       field->ip,
+                                       field->parent_ip);
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                break;
+       }
        case TRACE_CTX:
-       case TRACE_WAKE:
-               S = entry->ctx.prev_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.prev_state] : 'X';
-               T = entry->ctx.next_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.next_state] : 'X';
+       case TRACE_WAKE: {
+               struct ctx_switch_entry *field;
+
+               trace_assign_type(field, entry);
+
+               S = field->prev_state < sizeof(state_to_char) ?
+                       state_to_char[field->prev_state] : 'X';
+               T = field->next_state < sizeof(state_to_char) ?
+                       state_to_char[field->next_state] : 'X';
                if (entry->type == TRACE_WAKE)
                        S = '+';
-               ret = trace_seq_printf(s, "%d %d %c %d %d %c\n",
-                                      entry->ctx.prev_pid,
-                                      entry->ctx.prev_prio,
+               ret = trace_seq_printf(s, "%d %d %c %d %d %d %c\n",
+                                      field->prev_pid,
+                                      field->prev_prio,
                                       S,
-                                      entry->ctx.next_pid,
-                                      entry->ctx.next_prio,
+                                      field->next_cpu,
+                                      field->next_pid,
+                                      field->next_prio,
                                       T);
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                break;
+       }
        case TRACE_SPECIAL:
-       case TRACE_STACK:
+       case TRACE_STACK: {
+               struct special_entry *field;
+
+               trace_assign_type(field, entry);
+
                ret = trace_seq_printf(s, "# %ld %ld %ld\n",
-                                entry->special.arg1,
-                                entry->special.arg2,
-                                entry->special.arg3);
+                                field->arg1,
+                                field->arg2,
+                                field->arg3);
                if (!ret)
-                       return 0;
+                       return TRACE_TYPE_PARTIAL_LINE;
                break;
        }
-       return 1;
+       case TRACE_PRINT: {
+               struct print_entry *field;
+
+               trace_assign_type(field, entry);
+
+               trace_seq_printf(s, "# %lx %s", field->ip, field->buf);
+               if (entry->flags & TRACE_FLAG_CONT)
+                       trace_seq_print_cont(s, iter);
+               break;
+       }
+       }
+       return TRACE_TYPE_HANDLED;
 }
 
 #define SEQ_PUT_FIELD_RET(s, x)                                \
@@ -1714,7 +1676,7 @@ do {                                                      \
                return 0;                               \
 } while (0)
 
-static int print_hex_fmt(struct trace_iterator *iter)
+static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
 {
        struct trace_seq *s = &iter->seq;
        unsigned char newline = '\n';
@@ -1723,97 +1685,139 @@ static int print_hex_fmt(struct trace_iterator *iter)
 
        entry = iter->ent;
 
+       if (entry->type == TRACE_CONT)
+               return TRACE_TYPE_HANDLED;
+
        SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
        SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
-       SEQ_PUT_HEX_FIELD_RET(s, entry->t);
+       SEQ_PUT_HEX_FIELD_RET(s, iter->ts);
 
        switch (entry->type) {
-       case TRACE_FN:
-               SEQ_PUT_HEX_FIELD_RET(s, entry->fn.ip);
-               SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip);
+       case TRACE_FN: {
+               struct ftrace_entry *field;
+
+               trace_assign_type(field, entry);
+
+               SEQ_PUT_HEX_FIELD_RET(s, field->ip);
+               SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
                break;
+       }
        case TRACE_CTX:
-       case TRACE_WAKE:
-               S = entry->ctx.prev_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.prev_state] : 'X';
-               T = entry->ctx.next_state < sizeof(state_to_char) ?
-                       state_to_char[entry->ctx.next_state] : 'X';
+       case TRACE_WAKE: {
+               struct ctx_switch_entry *field;
+
+               trace_assign_type(field, entry);
+
+               S = field->prev_state < sizeof(state_to_char) ?
+                       state_to_char[field->prev_state] : 'X';
+               T = field->next_state < sizeof(state_to_char) ?
+                       state_to_char[field->next_state] : 'X';
                if (entry->type == TRACE_WAKE)
                        S = '+';
-               SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_pid);
-               SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_prio);
+               SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
+               SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
                SEQ_PUT_HEX_FIELD_RET(s, S);
-               SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_pid);
-               SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_prio);
-               SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip);
+               SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
+               SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
+               SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
                SEQ_PUT_HEX_FIELD_RET(s, T);
                break;
+       }
        case TRACE_SPECIAL:
-       case TRACE_STACK:
-               SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg1);
-               SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg2);
-               SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg3);
+       case TRACE_STACK: {
+               struct special_entry *field;
+
+               trace_assign_type(field, entry);
+
+               SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
+               SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
+               SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
                break;
        }
+       }
        SEQ_PUT_FIELD_RET(s, newline);
 
-       return 1;
+       return TRACE_TYPE_HANDLED;
 }
 
-static int print_bin_fmt(struct trace_iterator *iter)
+static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
 {
        struct trace_seq *s = &iter->seq;
        struct trace_entry *entry;
 
        entry = iter->ent;
 
+       if (entry->type == TRACE_CONT)
+               return TRACE_TYPE_HANDLED;
+
        SEQ_PUT_FIELD_RET(s, entry->pid);
-       SEQ_PUT_FIELD_RET(s, entry->cpu);
-       SEQ_PUT_FIELD_RET(s, entry->t);
+       SEQ_PUT_FIELD_RET(s, iter->cpu);
+       SEQ_PUT_FIELD_RET(s, iter->ts);
 
        switch (entry->type) {
-       case TRACE_FN:
-               SEQ_PUT_FIELD_RET(s, entry->fn.ip);
-               SEQ_PUT_FIELD_RET(s, entry->fn.parent_ip);
+       case TRACE_FN: {
+               struct ftrace_entry *field;
+
+               trace_assign_type(field, entry);
+
+               SEQ_PUT_FIELD_RET(s, field->ip);
+               SEQ_PUT_FIELD_RET(s, field->parent_ip);
                break;
-       case TRACE_CTX:
-               SEQ_PUT_FIELD_RET(s, entry->ctx.prev_pid);
-               SEQ_PUT_FIELD_RET(s, entry->ctx.prev_prio);
-               SEQ_PUT_FIELD_RET(s, entry->ctx.prev_state);
-               SEQ_PUT_FIELD_RET(s, entry->ctx.next_pid);
-               SEQ_PUT_FIELD_RET(s, entry->ctx.next_prio);
-               SEQ_PUT_FIELD_RET(s, entry->ctx.next_state);
+       }
+       case TRACE_CTX: {
+               struct ctx_switch_entry *field;
+
+               trace_assign_type(field, entry);
+
+               SEQ_PUT_FIELD_RET(s, field->prev_pid);
+               SEQ_PUT_FIELD_RET(s, field->prev_prio);
+               SEQ_PUT_FIELD_RET(s, field->prev_state);
+               SEQ_PUT_FIELD_RET(s, field->next_pid);
+               SEQ_PUT_FIELD_RET(s, field->next_prio);
+               SEQ_PUT_FIELD_RET(s, field->next_state);
                break;
+       }
        case TRACE_SPECIAL:
-       case TRACE_STACK:
-               SEQ_PUT_FIELD_RET(s, entry->special.arg1);
-               SEQ_PUT_FIELD_RET(s, entry->special.arg2);
-               SEQ_PUT_FIELD_RET(s, entry->special.arg3);
+       case TRACE_STACK: {
+               struct special_entry *field;
+
+               trace_assign_type(field, entry);
+
+               SEQ_PUT_FIELD_RET(s, field->arg1);
+               SEQ_PUT_FIELD_RET(s, field->arg2);
+               SEQ_PUT_FIELD_RET(s, field->arg3);
                break;
        }
+       }
        return 1;
 }
 
 static int trace_empty(struct trace_iterator *iter)
 {
-       struct trace_array_cpu *data;
        int cpu;
 
        for_each_tracing_cpu(cpu) {
-               data = iter->tr->data[cpu];
-
-               if (head_page(data) && data->trace_idx &&
-                   (data->trace_tail != data->trace_head ||
-                    data->trace_tail_idx != data->trace_head_idx))
-                       return 0;
+               if (iter->buffer_iter[cpu]) {
+                       if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
+                               return 0;
+               } else {
+                       if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu))
+                               return 0;
+               }
        }
+
        return 1;
 }
 
-static int print_trace_line(struct trace_iterator *iter)
+static enum print_line_t print_trace_line(struct trace_iterator *iter)
 {
-       if (iter->trace && iter->trace->print_line)
-               return iter->trace->print_line(iter);
+       enum print_line_t ret;
+
+       if (iter->trace && iter->trace->print_line) {
+               ret = iter->trace->print_line(iter);
+               if (ret != TRACE_TYPE_UNHANDLED)
+                       return ret;
+       }
 
        if (trace_flags & TRACE_ITER_BIN)
                return print_bin_fmt(iter);
@@ -1869,6 +1873,8 @@ static struct trace_iterator *
 __tracing_open(struct inode *inode, struct file *file, int *ret)
 {
        struct trace_iterator *iter;
+       struct seq_file *m;
+       int cpu;
 
        if (tracing_disabled) {
                *ret = -ENODEV;
@@ -1889,28 +1895,45 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
        iter->trace = current_trace;
        iter->pos = -1;
 
+       for_each_tracing_cpu(cpu) {
+
+               iter->buffer_iter[cpu] =
+                       ring_buffer_read_start(iter->tr->buffer, cpu);
+
+               if (!iter->buffer_iter[cpu])
+                       goto fail_buffer;
+       }
+
        /* TODO stop tracer */
        *ret = seq_open(file, &tracer_seq_ops);
-       if (!*ret) {
-               struct seq_file *m = file->private_data;
-               m->private = iter;
+       if (*ret)
+               goto fail_buffer;
 
-               /* stop the trace while dumping */
-               if (iter->tr->ctrl) {
-                       tracer_enabled = 0;
-                       ftrace_function_enabled = 0;
-               }
+       m = file->private_data;
+       m->private = iter;
 
-               if (iter->trace && iter->trace->open)
-                       iter->trace->open(iter);
-       } else {
-               kfree(iter);
-               iter = NULL;
+       /* stop the trace while dumping */
+       if (iter->tr->ctrl) {
+               tracer_enabled = 0;
+               ftrace_function_enabled = 0;
        }
+
+       if (iter->trace && iter->trace->open)
+                       iter->trace->open(iter);
+
        mutex_unlock(&trace_types_lock);
 
  out:
        return iter;
+
+ fail_buffer:
+       for_each_tracing_cpu(cpu) {
+               if (iter->buffer_iter[cpu])
+                       ring_buffer_read_finish(iter->buffer_iter[cpu]);
+       }
+       mutex_unlock(&trace_types_lock);
+
+       return ERR_PTR(-ENOMEM);
 }
 
 int tracing_open_generic(struct inode *inode, struct file *filp)
@@ -1926,8 +1949,14 @@ int tracing_release(struct inode *inode, struct file *file)
 {
        struct seq_file *m = (struct seq_file *)file->private_data;
        struct trace_iterator *iter = m->private;
+       int cpu;
 
        mutex_lock(&trace_types_lock);
+       for_each_tracing_cpu(cpu) {
+               if (iter->buffer_iter[cpu])
+                       ring_buffer_read_finish(iter->buffer_iter[cpu]);
+       }
+
        if (iter->trace && iter->trace->close)
                iter->trace->close(iter);
 
@@ -2352,9 +2381,11 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
        struct tracer *t;
        char buf[max_tracer_type_len+1];
        int i;
+       size_t ret;
 
        if (cnt > max_tracer_type_len)
                cnt = max_tracer_type_len;
+       ret = cnt;
 
        if (copy_from_user(&buf, ubuf, cnt))
                return -EFAULT;
@@ -2370,7 +2401,11 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
                if (strcmp(t->name, buf) == 0)
                        break;
        }
-       if (!t || t == current_trace)
+       if (!t) {
+               ret = -EINVAL;
+               goto out;
+       }
+       if (t == current_trace)
                goto out;
 
        if (current_trace && current_trace->reset)
@@ -2383,9 +2418,10 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
  out:
        mutex_unlock(&trace_types_lock);
 
-       filp->f_pos += cnt;
+       if (ret == cnt)
+               filp->f_pos += cnt;
 
-       return cnt;
+       return ret;
 }
 
 static ssize_t
@@ -2500,20 +2536,12 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
                  size_t cnt, loff_t *ppos)
 {
        struct trace_iterator *iter = filp->private_data;
-       struct trace_array_cpu *data;
-       static cpumask_t mask;
-       unsigned long flags;
-#ifdef CONFIG_FTRACE
-       int ftrace_save;
-#endif
-       int cpu;
        ssize_t sret;
 
        /* return any leftover data */
        sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
        if (sret != -EBUSY)
                return sret;
-       sret = 0;
 
        trace_seq_reset(&iter->seq);
 
@@ -2524,6 +2552,8 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
                        goto out;
        }
 
+waitagain:
+       sret = 0;
        while (trace_empty(iter)) {
 
                if ((filp->f_flags & O_NONBLOCK)) {
@@ -2588,46 +2618,12 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
               offsetof(struct trace_iterator, seq));
        iter->pos = -1;
 
-       /*
-        * We need to stop all tracing on all CPUS to read the
-        * the next buffer. This is a bit expensive, but is
-        * not done often. We fill all what we can read,
-        * and then release the locks again.
-        */
-
-       cpus_clear(mask);
-       local_irq_save(flags);
-#ifdef CONFIG_FTRACE
-       ftrace_save = ftrace_enabled;
-       ftrace_enabled = 0;
-#endif
-       smp_wmb();
-       for_each_tracing_cpu(cpu) {
-               data = iter->tr->data[cpu];
-
-               if (!head_page(data) || !data->trace_idx)
-                       continue;
-
-               atomic_inc(&data->disabled);
-               cpu_set(cpu, mask);
-       }
-
-       for_each_cpu_mask(cpu, mask) {
-               data = iter->tr->data[cpu];
-               __raw_spin_lock(&data->lock);
-
-               if (data->overrun > iter->last_overrun[cpu])
-                       iter->overrun[cpu] +=
-                               data->overrun - iter->last_overrun[cpu];
-               iter->last_overrun[cpu] = data->overrun;
-       }
-
        while (find_next_entry_inc(iter) != NULL) {
-               int ret;
+               enum print_line_t ret;
                int len = iter->seq.len;
 
                ret = print_trace_line(iter);
-               if (!ret) {
+               if (ret == TRACE_TYPE_PARTIAL_LINE) {
                        /* don't print partial lines */
                        iter->seq.len = len;
                        break;
@@ -2639,26 +2635,17 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
                        break;
        }
 
-       for_each_cpu_mask(cpu, mask) {
-               data = iter->tr->data[cpu];
-               __raw_spin_unlock(&data->lock);
-       }
-
-       for_each_cpu_mask(cpu, mask) {
-               data = iter->tr->data[cpu];
-               atomic_dec(&data->disabled);
-       }
-#ifdef CONFIG_FTRACE
-       ftrace_enabled = ftrace_save;
-#endif
-       local_irq_restore(flags);
-
        /* Now copy what we have to the user */
        sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
        if (iter->seq.readpos >= iter->seq.len)
                trace_seq_reset(&iter->seq);
+
+       /*
+        * If there was nothing to send to user, inspite of consuming trace
+        * entries, go back to wait for more entries.
+        */
        if (sret == -EBUSY)
-               sret = 0;
+               goto waitagain;
 
 out:
        mutex_unlock(&trace_types_lock);
@@ -2684,7 +2671,8 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 {
        unsigned long val;
        char buf[64];
-       int i, ret;
+       int ret;
+       struct trace_array *tr = filp->private_data;
 
        if (cnt >= sizeof(buf))
                return -EINVAL;
@@ -2704,59 +2692,38 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 
        mutex_lock(&trace_types_lock);
 
-       if (current_trace != &no_tracer) {
+       if (tr->ctrl) {
                cnt = -EBUSY;
-               pr_info("ftrace: set current_tracer to none"
+               pr_info("ftrace: please disable tracing"
                        " before modifying buffer size\n");
                goto out;
        }
 
-       if (val > global_trace.entries) {
-               long pages_requested;
-               unsigned long freeable_pages;
-
-               /* make sure we have enough memory before mapping */
-               pages_requested =
-                       (val + (ENTRIES_PER_PAGE-1)) / ENTRIES_PER_PAGE;
-
-               /* account for each buffer (and max_tr) */
-               pages_requested *= tracing_nr_buffers * 2;
-
-               /* Check for overflow */
-               if (pages_requested < 0) {
-                       cnt = -ENOMEM;
+       if (val != global_trace.entries) {
+               ret = ring_buffer_resize(global_trace.buffer, val);
+               if (ret < 0) {
+                       cnt = ret;
                        goto out;
                }
 
-               freeable_pages = determine_dirtyable_memory();
-
-               /* we only allow to request 1/4 of useable memory */
-               if (pages_requested >
-                   ((freeable_pages + tracing_pages_allocated) / 4)) {
-                       cnt = -ENOMEM;
-                       goto out;
-               }
-
-               while (global_trace.entries < val) {
-                       if (trace_alloc_page()) {
-                               cnt = -ENOMEM;
-                               goto out;
+               ret = ring_buffer_resize(max_tr.buffer, val);
+               if (ret < 0) {
+                       int r;
+                       cnt = ret;
+                       r = ring_buffer_resize(global_trace.buffer,
+                                              global_trace.entries);
+                       if (r < 0) {
+                               /* AARGH! We are left with different
+                                * size max buffer!!!! */
+                               WARN_ON(1);
+                               tracing_disabled = 1;
                        }
-                       /* double check that we don't go over the known pages */
-                       if (tracing_pages_allocated > pages_requested)
-                               break;
+                       goto out;
                }
 
-       } else {
-               /* include the number of entries in val (inc of page entries) */
-               while (global_trace.entries > val + (ENTRIES_PER_PAGE - 1))
-                       trace_free_page();
+               global_trace.entries = val;
        }
 
-       /* check integrity */
-       for_each_tracing_cpu(i)
-               check_pages(global_trace.data[i]);
-
        filp->f_pos += cnt;
 
        /* If check pages failed, return ENOMEM */
@@ -2769,6 +2736,52 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
        return cnt;
 }
 
+static int mark_printk(const char *fmt, ...)
+{
+       int ret;
+       va_list args;
+       va_start(args, fmt);
+       ret = trace_vprintk(0, fmt, args);
+       va_end(args);
+       return ret;
+}
+
+static ssize_t
+tracing_mark_write(struct file *filp, const char __user *ubuf,
+                                       size_t cnt, loff_t *fpos)
+{
+       char *buf;
+       char *end;
+       struct trace_array *tr = &global_trace;
+
+       if (!tr->ctrl || tracing_disabled)
+               return -EINVAL;
+
+       if (cnt > TRACE_BUF_SIZE)
+               cnt = TRACE_BUF_SIZE;
+
+       buf = kmalloc(cnt + 1, GFP_KERNEL);
+       if (buf == NULL)
+               return -ENOMEM;
+
+       if (copy_from_user(buf, ubuf, cnt)) {
+               kfree(buf);
+               return -EFAULT;
+       }
+
+       /* Cut from the first nil or newline. */
+       buf[cnt] = '\0';
+       end = strchr(buf, '\n');
+       if (end)
+               *end = '\0';
+
+       cnt = mark_printk("%s\n", buf);
+       kfree(buf);
+       *fpos += cnt;
+
+       return cnt;
+}
+
 static struct file_operations tracing_max_lat_fops = {
        .open           = tracing_open_generic,
        .read           = tracing_max_lat_read,
@@ -2800,6 +2813,11 @@ static struct file_operations tracing_entries_fops = {
        .write          = tracing_entries_write,
 };
 
+static struct file_operations tracing_mark_fops = {
+       .open           = tracing_open_generic,
+       .write          = tracing_mark_write,
+};
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 
 static ssize_t
@@ -2846,7 +2864,7 @@ struct dentry *tracing_init_dentry(void)
 #include "trace_selftest.c"
 #endif
 
-static __init void tracer_init_debugfs(void)
+static __init int tracer_init_debugfs(void)
 {
        struct dentry *d_tracer;
        struct dentry *entry;
@@ -2881,12 +2899,12 @@ static __init void tracer_init_debugfs(void)
        entry = debugfs_create_file("available_tracers", 0444, d_tracer,
                                    &global_trace, &show_traces_fops);
        if (!entry)
-               pr_warning("Could not create debugfs 'trace' entry\n");
+               pr_warning("Could not create debugfs 'available_tracers' entry\n");
 
        entry = debugfs_create_file("current_tracer", 0444, d_tracer,
                                    &global_trace, &set_tracer_fops);
        if (!entry)
-               pr_warning("Could not create debugfs 'trace' entry\n");
+               pr_warning("Could not create debugfs 'current_tracer' entry\n");
 
        entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer,
                                    &tracing_max_latency,
@@ -2899,7 +2917,7 @@ static __init void tracer_init_debugfs(void)
                                    &tracing_thresh, &tracing_max_lat_fops);
        if (!entry)
                pr_warning("Could not create debugfs "
-                          "'tracing_threash' entry\n");
+                          "'tracing_thresh' entry\n");
        entry = debugfs_create_file("README", 0644, d_tracer,
                                    NULL, &tracing_readme_fops);
        if (!entry)
@@ -2909,13 +2927,19 @@ static __init void tracer_init_debugfs(void)
                                    NULL, &tracing_pipe_fops);
        if (!entry)
                pr_warning("Could not create debugfs "
-                          "'tracing_threash' entry\n");
+                          "'trace_pipe' entry\n");
 
        entry = debugfs_create_file("trace_entries", 0644, d_tracer,
                                    &global_trace, &tracing_entries_fops);
        if (!entry)
                pr_warning("Could not create debugfs "
-                          "'tracing_threash' entry\n");
+                          "'trace_entries' entry\n");
+
+       entry = debugfs_create_file("trace_marker", 0220, d_tracer,
+                                   NULL, &tracing_mark_fops);
+       if (!entry)
+               pr_warning("Could not create debugfs "
+                          "'trace_marker' entry\n");
 
 #ifdef CONFIG_DYNAMIC_FTRACE
        entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer,
@@ -2928,230 +2952,263 @@ static __init void tracer_init_debugfs(void)
 #ifdef CONFIG_SYSPROF_TRACER
        init_tracer_sysprof_debugfs(d_tracer);
 #endif
+       return 0;
 }
 
-static int trace_alloc_page(void)
+int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 {
+       static DEFINE_SPINLOCK(trace_buf_lock);
+       static char trace_buf[TRACE_BUF_SIZE];
+
+       struct ring_buffer_event *event;
+       struct trace_array *tr = &global_trace;
        struct trace_array_cpu *data;
-       struct page *page, *tmp;
-       LIST_HEAD(pages);
-       void *array;
-       unsigned pages_allocated = 0;
-       int i;
+       struct print_entry *entry;
+       unsigned long flags, irq_flags;
+       int cpu, len = 0, size, pc;
 
-       /* first allocate a page for each CPU */
-       for_each_tracing_cpu(i) {
-               array = (void *)__get_free_page(GFP_KERNEL);
-               if (array == NULL) {
-                       printk(KERN_ERR "tracer: failed to allocate page"
-                              "for trace buffer!\n");
-                       goto free_pages;
-               }
+       if (!tr->ctrl || tracing_disabled)
+               return 0;
+
+       pc = preempt_count();
+       preempt_disable_notrace();
+       cpu = raw_smp_processor_id();
+       data = tr->data[cpu];
 
-               pages_allocated++;
-               page = virt_to_page(array);
-               list_add(&page->lru, &pages);
+       if (unlikely(atomic_read(&data->disabled)))
+               goto out;
 
-/* Only allocate if we are actually using the max trace */
-#ifdef CONFIG_TRACER_MAX_TRACE
-               array = (void *)__get_free_page(GFP_KERNEL);
-               if (array == NULL) {
-                       printk(KERN_ERR "tracer: failed to allocate page"
-                              "for trace buffer!\n");
-                       goto free_pages;
-               }
-               pages_allocated++;
-               page = virt_to_page(array);
-               list_add(&page->lru, &pages);
-#endif
-       }
+       spin_lock_irqsave(&trace_buf_lock, flags);
+       len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
-       /* Now that we successfully allocate a page per CPU, add them */
-       for_each_tracing_cpu(i) {
-               data = global_trace.data[i];
-               page = list_entry(pages.next, struct page, lru);
-               list_del_init(&page->lru);
-               list_add_tail(&page->lru, &data->trace_pages);
-               ClearPageLRU(page);
+       len = min(len, TRACE_BUF_SIZE-1);
+       trace_buf[len] = 0;
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-               data = max_tr.data[i];
-               page = list_entry(pages.next, struct page, lru);
-               list_del_init(&page->lru);
-               list_add_tail(&page->lru, &data->trace_pages);
-               SetPageLRU(page);
-#endif
-       }
-       tracing_pages_allocated += pages_allocated;
-       global_trace.entries += ENTRIES_PER_PAGE;
+       size = sizeof(*entry) + len + 1;
+       event = ring_buffer_lock_reserve(tr->buffer, size, &irq_flags);
+       if (!event)
+               goto out_unlock;
+       entry = ring_buffer_event_data(event);
+       tracing_generic_entry_update(&entry->ent, flags, pc);
+       entry->ent.type                 = TRACE_PRINT;
+       entry->ip                       = ip;
 
-       return 0;
+       memcpy(&entry->buf, trace_buf, len);
+       entry->buf[len] = 0;
+       ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
 
- free_pages:
-       list_for_each_entry_safe(page, tmp, &pages, lru) {
-               list_del_init(&page->lru);
-               __free_page(page);
-       }
-       return -ENOMEM;
+ out_unlock:
+       spin_unlock_irqrestore(&trace_buf_lock, flags);
+
+ out:
+       preempt_enable_notrace();
+
+       return len;
 }
+EXPORT_SYMBOL_GPL(trace_vprintk);
 
-static int trace_free_page(void)
+int __ftrace_printk(unsigned long ip, const char *fmt, ...)
 {
-       struct trace_array_cpu *data;
-       struct page *page;
-       struct list_head *p;
-       int i;
-       int ret = 0;
+       int ret;
+       va_list ap;
 
-       /* free one page from each buffer */
-       for_each_tracing_cpu(i) {
-               data = global_trace.data[i];
-               p = data->trace_pages.next;
-               if (p == &data->trace_pages) {
-                       /* should never happen */
-                       WARN_ON(1);
-                       tracing_disabled = 1;
-                       ret = -1;
-                       break;
-               }
-               page = list_entry(p, struct page, lru);
-               ClearPageLRU(page);
-               list_del(&page->lru);
-               tracing_pages_allocated--;
-               tracing_pages_allocated--;
-               __free_page(page);
+       if (!(trace_flags & TRACE_ITER_PRINTK))
+               return 0;
 
-               tracing_reset(data);
+       va_start(ap, fmt);
+       ret = trace_vprintk(ip, fmt, ap);
+       va_end(ap);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(__ftrace_printk);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-               data = max_tr.data[i];
-               p = data->trace_pages.next;
-               if (p == &data->trace_pages) {
-                       /* should never happen */
-                       WARN_ON(1);
-                       tracing_disabled = 1;
-                       ret = -1;
-                       break;
-               }
-               page = list_entry(p, struct page, lru);
-               ClearPageLRU(page);
-               list_del(&page->lru);
-               __free_page(page);
+static int trace_panic_handler(struct notifier_block *this,
+                              unsigned long event, void *unused)
+{
+       ftrace_dump();
+       return NOTIFY_OK;
+}
 
-               tracing_reset(data);
-#endif
-       }
-       global_trace.entries -= ENTRIES_PER_PAGE;
+static struct notifier_block trace_panic_notifier = {
+       .notifier_call  = trace_panic_handler,
+       .next           = NULL,
+       .priority       = 150   /* priority: INT_MAX >= x >= 0 */
+};
 
-       return ret;
+static int trace_die_handler(struct notifier_block *self,
+                            unsigned long val,
+                            void *data)
+{
+       switch (val) {
+       case DIE_OOPS:
+               ftrace_dump();
+               break;
+       default:
+               break;
+       }
+       return NOTIFY_OK;
 }
 
-__init static int tracer_alloc_buffers(void)
+static struct notifier_block trace_die_notifier = {
+       .notifier_call = trace_die_handler,
+       .priority = 200
+};
+
+/*
+ * printk is set to max of 1024, we really don't need it that big.
+ * Nothing should be printing 1000 characters anyway.
+ */
+#define TRACE_MAX_PRINT                1000
+
+/*
+ * Define here KERN_TRACE so that we have one place to modify
+ * it if we decide to change what log level the ftrace dump
+ * should be at.
+ */
+#define KERN_TRACE             KERN_INFO
+
+static void
+trace_printk_seq(struct trace_seq *s)
 {
-       struct trace_array_cpu *data;
-       void *array;
-       struct page *page;
-       int pages = 0;
-       int ret = -ENOMEM;
-       int i;
+       /* Probably should print a warning here. */
+       if (s->len >= 1000)
+               s->len = 1000;
 
-       /* TODO: make the number of buffers hot pluggable with CPUS */
-       tracing_nr_buffers = num_possible_cpus();
-       tracing_buffer_mask = cpu_possible_map;
+       /* should be zero ended, but we are paranoid. */
+       s->buffer[s->len] = 0;
 
-       /* Allocate the first page for all buffers */
-       for_each_tracing_cpu(i) {
-               data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
-               max_tr.data[i] = &per_cpu(max_data, i);
+       printk(KERN_TRACE "%s", s->buffer);
 
-               array = (void *)__get_free_page(GFP_KERNEL);
-               if (array == NULL) {
-                       printk(KERN_ERR "tracer: failed to allocate page"
-                              "for trace buffer!\n");
-                       goto free_buffers;
-               }
+       trace_seq_reset(s);
+}
 
-               /* set the array to the list */
-               INIT_LIST_HEAD(&data->trace_pages);
-               page = virt_to_page(array);
-               list_add(&page->lru, &data->trace_pages);
-               /* use the LRU flag to differentiate the two buffers */
-               ClearPageLRU(page);
 
-               data->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
-               max_tr.data[i]->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+void ftrace_dump(void)
+{
+       static DEFINE_SPINLOCK(ftrace_dump_lock);
+       /* use static because iter can be a bit big for the stack */
+       static struct trace_iterator iter;
+       static cpumask_t mask;
+       static int dump_ran;
+       unsigned long flags;
+       int cnt = 0, cpu;
 
-/* Only allocate if we are actually using the max trace */
-#ifdef CONFIG_TRACER_MAX_TRACE
-               array = (void *)__get_free_page(GFP_KERNEL);
-               if (array == NULL) {
-                       printk(KERN_ERR "tracer: failed to allocate page"
-                              "for trace buffer!\n");
-                       goto free_buffers;
-               }
+       /* only one dump */
+       spin_lock_irqsave(&ftrace_dump_lock, flags);
+       if (dump_ran)
+               goto out;
 
-               INIT_LIST_HEAD(&max_tr.data[i]->trace_pages);
-               page = virt_to_page(array);
-               list_add(&page->lru, &max_tr.data[i]->trace_pages);
-               SetPageLRU(page);
-#endif
+       dump_ran = 1;
+
+       /* No turning back! */
+       ftrace_kill_atomic();
+
+       for_each_tracing_cpu(cpu) {
+               atomic_inc(&global_trace.data[cpu]->disabled);
        }
 
+       printk(KERN_TRACE "Dumping ftrace buffer:\n");
+
+       iter.tr = &global_trace;
+       iter.trace = current_trace;
+
        /*
-        * Since we allocate by orders of pages, we may be able to
-        * round up a bit.
+        * We need to stop all tracing on all CPUS to read the
+        * the next buffer. This is a bit expensive, but is
+        * not done often. We fill all what we can read,
+        * and then release the locks again.
         */
-       global_trace.entries = ENTRIES_PER_PAGE;
-       pages++;
 
-       while (global_trace.entries < trace_nr_entries) {
-               if (trace_alloc_page())
-                       break;
-               pages++;
+       cpus_clear(mask);
+
+       while (!trace_empty(&iter)) {
+
+               if (!cnt)
+                       printk(KERN_TRACE "---------------------------------\n");
+
+               cnt++;
+
+               /* reset all but tr, trace, and overruns */
+               memset(&iter.seq, 0,
+                      sizeof(struct trace_iterator) -
+                      offsetof(struct trace_iterator, seq));
+               iter.iter_flags |= TRACE_FILE_LAT_FMT;
+               iter.pos = -1;
+
+               if (find_next_entry_inc(&iter) != NULL) {
+                       print_trace_line(&iter);
+                       trace_consume(&iter);
+               }
+
+               trace_printk_seq(&iter.seq);
        }
-       max_tr.entries = global_trace.entries;
 
-       pr_info("tracer: %d pages allocated for %ld entries of %ld bytes\n",
-               pages, trace_nr_entries, (long)TRACE_ENTRY_SIZE);
-       pr_info("   actual entries %ld\n", global_trace.entries);
+       if (!cnt)
+               printk(KERN_TRACE "   (ftrace buffer empty)\n");
+       else
+               printk(KERN_TRACE "---------------------------------\n");
 
-       tracer_init_debugfs();
+ out:
+       spin_unlock_irqrestore(&ftrace_dump_lock, flags);
+}
+
+__init static int tracer_alloc_buffers(void)
+{
+       struct trace_array_cpu *data;
+       int i;
+
+       /* TODO: make the number of buffers hot pluggable with CPUS */
+       tracing_buffer_mask = cpu_possible_map;
+
+       global_trace.buffer = ring_buffer_alloc(trace_buf_size,
+                                                  TRACE_BUFFER_FLAGS);
+       if (!global_trace.buffer) {
+               printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
+               WARN_ON(1);
+               return 0;
+       }
+       global_trace.entries = ring_buffer_size(global_trace.buffer);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+       max_tr.buffer = ring_buffer_alloc(trace_buf_size,
+                                            TRACE_BUFFER_FLAGS);
+       if (!max_tr.buffer) {
+               printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n");
+               WARN_ON(1);
+               ring_buffer_free(global_trace.buffer);
+               return 0;
+       }
+       max_tr.entries = ring_buffer_size(max_tr.buffer);
+       WARN_ON(max_tr.entries != global_trace.entries);
+#endif
+
+       /* Allocate the first page for all buffers */
+       for_each_tracing_cpu(i) {
+               data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
+               max_tr.data[i] = &per_cpu(max_data, i);
+       }
 
        trace_init_cmdlines();
 
-       register_tracer(&no_tracer);
-       current_trace = &no_tracer;
+       register_tracer(&nop_trace);
+#ifdef CONFIG_BOOT_TRACER
+       register_tracer(&boot_tracer);
+       current_trace = &boot_tracer;
+       current_trace->init(&global_trace);
+#else
+       current_trace = &nop_trace;
+#endif
 
        /* All seems OK, enable tracing */
        global_trace.ctrl = tracer_enabled;
        tracing_disabled = 0;
 
-       return 0;
-
- free_buffers:
-       for (i-- ; i >= 0; i--) {
-               struct page *page, *tmp;
-               struct trace_array_cpu *data = global_trace.data[i];
+       atomic_notifier_chain_register(&panic_notifier_list,
+                                      &trace_panic_notifier);
 
-               if (data) {
-                       list_for_each_entry_safe(page, tmp,
-                                                &data->trace_pages, lru) {
-                               list_del_init(&page->lru);
-                               __free_page(page);
-                       }
-               }
+       register_die_notifier(&trace_die_notifier);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-               data = max_tr.data[i];
-               if (data) {
-                       list_for_each_entry_safe(page, tmp,
-                                                &data->trace_pages, lru) {
-                               list_del_init(&page->lru);
-                               __free_page(page);
-                       }
-               }
-#endif
-       }
-       return ret;
+       return 0;
 }
-fs_initcall(tracer_alloc_buffers);
+early_initcall(tracer_alloc_buffers);
+fs_initcall(tracer_init_debugfs);