X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fcpuset.c;h=8da627d33804db7c9e30936fead573cedd4407e3;hb=0527168522c25121bdd5d5f1d3c5b484d972ea14;hp=50f5dc46368841de3497fe96534df12b871e530b;hpb=4c5cdb1e1f2a502069f57a60b5c6b97b8106c73c;p=linux-2.6-omap-h63xx.git diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 50f5dc46368..8da627d3380 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -38,7 +38,6 @@ #include #include #include -#include #include #include #include @@ -56,6 +55,8 @@ #include #include #include +#include +#include /* * Tracks how many cpusets are currently defined in system. @@ -64,7 +65,7 @@ */ int number_of_cpusets __read_mostly; -/* Retrieve the cpuset from a cgroup */ +/* Forward declare cgroup structures */ struct cgroup_subsys cpuset_subsys; struct cpuset; @@ -96,6 +97,12 @@ struct cpuset { /* partition number for rebuild_sched_domains() */ int pn; + + /* for custom sched domain */ + int relax_domain_level; + + /* used for walking a cpuset heirarchy */ + struct list_head stack_list; }; /* Retrieve the cpuset for a cgroup */ @@ -111,12 +118,16 @@ static inline struct cpuset *task_cs(struct task_struct *task) return container_of(task_subsys_state(task, cpuset_subsys_id), struct cpuset, css); } - +struct cpuset_hotplug_scanner { + struct cgroup_scanner scan; + struct cgroup *to; +}; /* bits in struct cpuset flags field */ typedef enum { CS_CPU_EXCLUSIVE, CS_MEM_EXCLUSIVE, + CS_MEM_HARDWALL, CS_MEMORY_MIGRATE, CS_SCHED_LOAD_BALANCE, CS_SPREAD_PAGE, @@ -134,6 +145,11 @@ static inline int is_mem_exclusive(const struct cpuset *cs) return test_bit(CS_MEM_EXCLUSIVE, &cs->flags); } +static inline int is_mem_hardwall(const struct cpuset *cs) +{ + return test_bit(CS_MEM_HARDWALL, &cs->flags); +} + static inline int is_sched_load_balance(const struct cpuset *cs) { return test_bit(CS_SCHED_LOAD_BALANCE, &cs->flags); @@ -160,17 +176,17 @@ static inline int is_spread_slab(const struct cpuset *cs) * number, and avoid having to lock and reload mems_allowed unless * the cpuset they're using changes generation. * - * A single, global generation is needed because attach_task() could + * A single, global generation is needed because cpuset_attach_task() could * reattach a task to a different cpuset, which must not have its * generation numbers aliased with those of that tasks previous cpuset. * * Generations are needed for mems_allowed because one task cannot - * modify anothers memory placement. So we must enable every task, + * modify another's memory placement. So we must enable every task, * on every visit to __alloc_pages(), to efficiently check whether * its current->cpuset->mems_allowed has changed, requiring an update * of its current->mems_allowed. * - * Since cpuset_mems_generation is guarded by manage_mutex, + * Since writes to cpuset_mems_generation are guarded by the cgroup lock * there is no need to mark it atomic. */ static int cpuset_mems_generation; @@ -182,17 +198,20 @@ static struct cpuset top_cpuset = { }; /* - * We have two global cpuset mutexes below. They can nest. - * It is ok to first take manage_mutex, then nest callback_mutex. We also - * require taking task_lock() when dereferencing a tasks cpuset pointer. - * See "The task_lock() exception", at the end of this comment. + * There are two global mutexes guarding cpuset structures. The first + * is the main control groups cgroup_mutex, accessed via + * cgroup_lock()/cgroup_unlock(). The second is the cpuset-specific + * callback_mutex, below. They can nest. It is ok to first take + * cgroup_mutex, then nest callback_mutex. We also require taking + * task_lock() when dereferencing a task's cpuset pointer. See "The + * task_lock() exception", at the end of this comment. * * A task must hold both mutexes to modify cpusets. If a task - * holds manage_mutex, then it blocks others wanting that mutex, + * holds cgroup_mutex, then it blocks others wanting that mutex, * ensuring that it is the only task able to also acquire callback_mutex * and be able to modify cpusets. It can perform various checks on * the cpuset structure first, knowing nothing will change. It can - * also allocate memory while just holding manage_mutex. While it is + * also allocate memory while just holding cgroup_mutex. While it is * performing these checks, various callback routines can briefly * acquire callback_mutex to query cpusets. Once it is ready to make * the changes, it takes callback_mutex, blocking everyone else. @@ -208,60 +227,16 @@ static struct cpuset top_cpuset = { * The task_struct fields mems_allowed and mems_generation may only * be accessed in the context of that task, so require no locks. * - * Any task can increment and decrement the count field without lock. - * So in general, code holding manage_mutex or callback_mutex can't rely - * on the count field not changing. However, if the count goes to - * zero, then only attach_task(), which holds both mutexes, can - * increment it again. Because a count of zero means that no tasks - * are currently attached, therefore there is no way a task attached - * to that cpuset can fork (the other way to increment the count). - * So code holding manage_mutex or callback_mutex can safely assume that - * if the count is zero, it will stay zero. Similarly, if a task - * holds manage_mutex or callback_mutex on a cpuset with zero count, it - * knows that the cpuset won't be removed, as cpuset_rmdir() needs - * both of those mutexes. - * * The cpuset_common_file_write handler for operations that modify - * the cpuset hierarchy holds manage_mutex across the entire operation, + * the cpuset hierarchy holds cgroup_mutex across the entire operation, * single threading all such cpuset modifications across the system. * * The cpuset_common_file_read() handlers only hold callback_mutex across * small pieces of code, such as when reading out possibly multi-word * cpumasks and nodemasks. * - * The fork and exit callbacks cpuset_fork() and cpuset_exit(), don't - * (usually) take either mutex. These are the two most performance - * critical pieces of code here. The exception occurs on cpuset_exit(), - * when a task in a notify_on_release cpuset exits. Then manage_mutex - * is taken, and if the cpuset count is zero, a usermode call made - * to /sbin/cpuset_release_agent with the name of the cpuset (path - * relative to the root of cpuset file system) as the argument. - * - * A cpuset can only be deleted if both its 'count' of using tasks - * is zero, and its list of 'children' cpusets is empty. Since all - * tasks in the system use _some_ cpuset, and since there is always at - * least one task in the system (init), therefore, top_cpuset - * always has either children cpusets and/or using tasks. So we don't - * need a special hack to ensure that top_cpuset cannot be deleted. - * - * The above "Tale of Two Semaphores" would be complete, but for: - * - * The task_lock() exception - * - * The need for this exception arises from the action of attach_task(), - * which overwrites one tasks cpuset pointer with another. It does - * so using both mutexes, however there are several performance - * critical places that need to reference task->cpuset without the - * expense of grabbing a system global mutex. Therefore except as - * noted below, when dereferencing or, as in attach_task(), modifying - * a tasks cpuset pointer we use task_lock(), which acts on a spinlock - * (task->alloc_lock) already in the task_struct routinely used for - * such matters. - * - * P.S. One more locking exception. RCU is used to guard the - * update of a tasks cpuset pointer by attach_task() and the - * access of task->cpuset->mems_generation via that pointer in - * the routine cpuset_update_task_memory_state(). + * Accessing a task's cpuset should be done in accordance with the + * guidelines for accessing subsystem state in kernel/cgroup.c */ static DEFINE_MUTEX(callback_mutex); @@ -354,15 +329,14 @@ static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask) * Do not call this routine if in_interrupt(). * * Call without callback_mutex or task_lock() held. May be - * called with or without manage_mutex held. Thanks in part to - * 'the_top_cpuset_hack', the tasks cpuset pointer will never - * be NULL. This routine also might acquire callback_mutex and - * current->mm->mmap_sem during call. + * called with or without cgroup_mutex held. Thanks in part to + * 'the_top_cpuset_hack', the task's cpuset pointer will never + * be NULL. This routine also might acquire callback_mutex during + * call. * * Reading current->cpuset->mems_generation doesn't need task_lock * to guard the current->cpuset derefence, because it is guarded - * from concurrent freeing of current->cpuset by attach_task(), - * using RCU. + * from concurrent freeing of current->cpuset using RCU. * * The rcu_dereference() is technically probably not needed, * as I don't actually mind if I see a new cpuset pointer but @@ -424,7 +398,7 @@ void cpuset_update_task_memory_state(void) * * One cpuset is a subset of another if all its allowed CPUs and * Memory Nodes are a subset of the other, and its exclusive flags - * are only set if the other's are set. Call holding manage_mutex. + * are only set if the other's are set. Call holding cgroup_mutex. */ static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q) @@ -442,7 +416,7 @@ static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q) * If we replaced the flag and mask values of the current cpuset * (cur) with those values in the trial cpuset (trial), would * our various subset and exclusive rules still be valid? Presumes - * manage_mutex held. + * cgroup_mutex held. * * 'cur' is the address of an actual, in-use cpuset. Operations * such as list traversal that depend on the actual address of the @@ -476,7 +450,10 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial) if (!is_cpuset_subset(trial, par)) return -EACCES; - /* If either I or some sibling (!= me) is exclusive, we can't overlap */ + /* + * If either I or some sibling (!= me) is exclusive, we can't + * overlap + */ list_for_each_entry(cont, &par->css.cgroup->children, sibling) { c = cgroup_cs(cont); if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) && @@ -510,6 +487,16 @@ static int cpusets_overlap(struct cpuset *a, struct cpuset *b) return cpus_intersects(a->cpus_allowed, b->cpus_allowed); } +static void +update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c) +{ + if (!dattr) + return; + if (dattr->relax_domain_level < c->relax_domain_level) + dattr->relax_domain_level = c->relax_domain_level; + return; +} + /* * rebuild_sched_domains() * @@ -537,10 +524,10 @@ static int cpusets_overlap(struct cpuset *a, struct cpuset *b) * * Call with cgroup_mutex held. May take callback_mutex during * call due to the kfifo_alloc() and kmalloc() calls. May nest - * a call to the lock_cpu_hotplug()/unlock_cpu_hotplug() pair. + * a call to the get_online_cpus()/put_online_cpus() pair. * Must not be called holding callback_mutex, because we must not - * call lock_cpu_hotplug() while holding callback_mutex. Elsewhere - * the kernel nests callback_mutex inside lock_cpu_hotplug() calls. + * call get_online_cpus() while holding callback_mutex. Elsewhere + * the kernel nests callback_mutex inside get_online_cpus() calls. * So the reverse nesting would risk an ABBA deadlock. * * The three key local variables below are: @@ -585,12 +572,14 @@ static void rebuild_sched_domains(void) int csn; /* how many cpuset ptrs in csa so far */ int i, j, k; /* indices for partition finding loops */ cpumask_t *doms; /* resulting partition; i.e. sched domains */ + struct sched_domain_attr *dattr; /* attributes for custom domains */ int ndoms; /* number of sched domains in result */ int nslot; /* next empty doms[] cpumask_t slot */ q = NULL; csa = NULL; doms = NULL; + dattr = NULL; /* Special case for the 99% of systems with one, full, sched domain */ if (is_sched_load_balance(&top_cpuset)) { @@ -598,6 +587,11 @@ static void rebuild_sched_domains(void) doms = kmalloc(sizeof(cpumask_t), GFP_KERNEL); if (!doms) goto rebuild; + dattr = kmalloc(sizeof(struct sched_domain_attr), GFP_KERNEL); + if (dattr) { + *dattr = SD_ATTR_INIT; + update_domain_attr(dattr, &top_cpuset); + } *doms = top_cpuset.cpus_allowed; goto rebuild; } @@ -654,6 +648,7 @@ restart: doms = kmalloc(ndoms * sizeof(cpumask_t), GFP_KERNEL); if (!doms) goto rebuild; + dattr = kmalloc(ndoms * sizeof(struct sched_domain_attr), GFP_KERNEL); for (nslot = 0, i = 0; i < csn; i++) { struct cpuset *a = csa[i]; @@ -676,12 +671,15 @@ restart: } cpus_clear(*dp); + if (dattr) + *(dattr + nslot) = SD_ATTR_INIT; for (j = i; j < csn; j++) { struct cpuset *b = csa[j]; if (apn == b->pn) { cpus_or(*dp, *dp, b->cpus_allowed); b->pn = -1; + update_domain_attr(dattr, b); } } nslot++; @@ -691,15 +689,16 @@ restart: rebuild: /* Have scheduler rebuild sched domains */ - lock_cpu_hotplug(); - partition_sched_domains(ndoms, doms); - unlock_cpu_hotplug(); + get_online_cpus(); + partition_sched_domains(ndoms, doms, dattr); + put_online_cpus(); done: if (q && !IS_ERR(q)) kfifo_free(q); kfree(csa); /* Don't kfree(doms) -- partition_sched_domains() does that. */ + /* Don't kfree(dattr) -- partition_sched_domains() does that. */ } static inline int started_after_time(struct task_struct *t1, @@ -732,22 +731,52 @@ static inline int started_after(void *p1, void *p2) return started_after_time(t1, &t2->start_time, t2); } -/* - * Call with manage_mutex held. May take callback_mutex during call. +/** + * cpuset_test_cpumask - test a task's cpus_allowed versus its cpuset's + * @tsk: task to test + * @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner + * + * Call with cgroup_mutex held. May take callback_mutex during call. + * Called for each task in a cgroup by cgroup_scan_tasks(). + * Return nonzero if this tasks's cpus_allowed mask should be changed (in other + * words, if its mask is not equal to its cpuset's mask). */ +static int cpuset_test_cpumask(struct task_struct *tsk, + struct cgroup_scanner *scan) +{ + return !cpus_equal(tsk->cpus_allowed, + (cgroup_cs(scan->cg))->cpus_allowed); +} + +/** + * cpuset_change_cpumask - make a task's cpus_allowed the same as its cpuset's + * @tsk: task to test + * @scan: struct cgroup_scanner containing the cgroup of the task + * + * Called by cgroup_scan_tasks() for each task in a cgroup whose + * cpus_allowed mask needs to be changed. + * + * We don't need to re-check for the cgroup/cpuset membership, since we're + * holding cgroup_lock() at this point. + */ +static void cpuset_change_cpumask(struct task_struct *tsk, + struct cgroup_scanner *scan) +{ + set_cpus_allowed_ptr(tsk, &((cgroup_cs(scan->cg))->cpus_allowed)); +} +/** + * update_cpumask - update the cpus_allowed mask of a cpuset and all tasks in it + * @cs: the cpuset to consider + * @buf: buffer of cpu numbers written to this cpuset + */ static int update_cpumask(struct cpuset *cs, char *buf) { struct cpuset trialcs; - int retval, i; - int is_load_balanced; - struct cgroup_iter it; - struct cgroup *cgrp = cs->css.cgroup; - struct task_struct *p, *dropped; - /* Never dereference latest_task, since it's not refcounted */ - struct task_struct *latest_task = NULL; + struct cgroup_scanner scan; struct ptr_heap heap; - struct timespec latest_time = { 0, 0 }; + int retval; + int is_load_balanced; /* top_cpuset.cpus_allowed tracks cpu_online_map; it's read-only */ if (cs == &top_cpuset) @@ -756,7 +785,7 @@ static int update_cpumask(struct cpuset *cs, char *buf) trialcs = *cs; /* - * An empty cpus_allowed is ok iff there are no tasks in the cpuset. + * An empty cpus_allowed is ok only if the cpuset has no tasks. * Since cpulist_parse() fails on an empty mask, we special case * that parsing. The validate_change() call ensures that cpusets * with tasks have cpus. @@ -777,6 +806,7 @@ static int update_cpumask(struct cpuset *cs, char *buf) /* Nothing to do if the cpus didn't change */ if (cpus_equal(cs->cpus_allowed, trialcs.cpus_allowed)) return 0; + retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, &started_after); if (retval) return retval; @@ -787,62 +817,19 @@ static int update_cpumask(struct cpuset *cs, char *buf) cs->cpus_allowed = trialcs.cpus_allowed; mutex_unlock(&callback_mutex); - again: /* * Scan tasks in the cpuset, and update the cpumasks of any - * that need an update. Since we can't call set_cpus_allowed() - * while holding tasklist_lock, gather tasks to be processed - * in a heap structure. If the statically-sized heap fills up, - * overflow tasks that started later, and in future iterations - * only consider tasks that started after the latest task in - * the previous pass. This guarantees forward progress and - * that we don't miss any tasks + * that need an update. */ - heap.size = 0; - cgroup_iter_start(cgrp, &it); - while ((p = cgroup_iter_next(cgrp, &it))) { - /* Only affect tasks that don't have the right cpus_allowed */ - if (cpus_equal(p->cpus_allowed, cs->cpus_allowed)) - continue; - /* - * Only process tasks that started after the last task - * we processed - */ - if (!started_after_time(p, &latest_time, latest_task)) - continue; - dropped = heap_insert(&heap, p); - if (dropped == NULL) { - get_task_struct(p); - } else if (dropped != p) { - get_task_struct(p); - put_task_struct(dropped); - } - } - cgroup_iter_end(cgrp, &it); - if (heap.size) { - for (i = 0; i < heap.size; i++) { - struct task_struct *p = heap.ptrs[i]; - if (i == 0) { - latest_time = p->start_time; - latest_task = p; - } - set_cpus_allowed(p, cs->cpus_allowed); - put_task_struct(p); - } - /* - * If we had to process any tasks at all, scan again - * in case some of them were in the middle of forking - * children that didn't notice the new cpumask - * restriction. Not the most efficient way to do it, - * but it avoids having to take callback_mutex in the - * fork path - */ - goto again; - } + scan.cg = cs->css.cgroup; + scan.test_task = cpuset_test_cpumask; + scan.process_task = cpuset_change_cpumask; + scan.heap = &heap; + cgroup_scan_tasks(&scan); heap_free(&heap); + if (is_load_balanced) rebuild_sched_domains(); - return 0; } @@ -854,11 +841,11 @@ static int update_cpumask(struct cpuset *cs, char *buf) * Temporarilly set tasks mems_allowed to target nodes of migration, * so that the migration code can allocate pages on these nodes. * - * Call holding manage_mutex, so our current->cpuset won't change - * during this call, as manage_mutex holds off any attach_task() + * Call holding cgroup_mutex, so current's cpuset won't change + * during this call, as manage_mutex holds off any cpuset_attach() * calls. Therefore we don't need to take task_lock around the * call to guarantee_online_mems(), as we know no one is changing - * our tasks cpuset. + * our task's cpuset. * * Hold callback_mutex around the two modifications of our tasks * mems_allowed to synchronize with cpuset_mems_allowed(). @@ -903,7 +890,7 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from, * the cpuset is marked 'memory_migrate', migrate the tasks * pages to the new memory. * - * Call with manage_mutex held. May take callback_mutex during call. + * Call with cgroup_mutex held. May take callback_mutex during call. * Will take tasklist_lock, scan tasklist for tasks in cpuset cs, * lock each such tasks mm->mmap_sem, scan its vma's and rebind * their mempolicies to the cpusets new mems_allowed. @@ -962,7 +949,7 @@ static int update_nodemask(struct cpuset *cs, char *buf) cs->mems_generation = cpuset_mems_generation++; mutex_unlock(&callback_mutex); - cpuset_being_rebound = cs; /* causes mpol_copy() rebind */ + cpuset_being_rebound = cs; /* causes mpol_dup() rebind */ fudge = 10; /* spare mmarray[] slots */ fudge += cpus_weight(cs->cpus_allowed); /* imagine one fork-bomb/cpu */ @@ -1013,10 +1000,10 @@ static int update_nodemask(struct cpuset *cs, char *buf) * rebind the vma mempolicies of each mm in mmarray[] to their * new cpuset, and release that mm. The mpol_rebind_mm() * call takes mmap_sem, which we couldn't take while holding - * tasklist_lock. Forks can happen again now - the mpol_copy() + * tasklist_lock. Forks can happen again now - the mpol_dup() * cpuset_being_rebound check will catch such forks, and rebind * their vma mempolicies too. Because we still hold the global - * cpuset manage_mutex, we know that no other rebind effort will + * cgroup_mutex, we know that no other rebind effort will * be contending for the global variable cpuset_being_rebound. * It's ok if we rebind the same mm twice; mpol_rebind_mm() * is idempotent. Also migrate pages in each mm to new nodes. @@ -1031,7 +1018,7 @@ static int update_nodemask(struct cpuset *cs, char *buf) mmput(mm); } - /* We're done rebinding vma's to this cpusets new mems_allowed. */ + /* We're done rebinding vmas to this cpuset's new mems_allowed. */ kfree(mmarray); cpuset_being_rebound = NULL; retval = 0; @@ -1044,40 +1031,37 @@ int current_cpuset_is_being_rebound(void) return task_cs(current) == cpuset_being_rebound; } -/* - * Call with manage_mutex held. - */ - -static int update_memory_pressure_enabled(struct cpuset *cs, char *buf) +static int update_relax_domain_level(struct cpuset *cs, char *buf) { - if (simple_strtoul(buf, NULL, 10) != 0) - cpuset_memory_pressure_enabled = 1; - else - cpuset_memory_pressure_enabled = 0; + int val = simple_strtol(buf, NULL, 10); + + if (val < 0) + val = -1; + + if (val != cs->relax_domain_level) { + cs->relax_domain_level = val; + rebuild_sched_domains(); + } + return 0; } /* * update_flag - read a 0 or a 1 in a file and update associated flag - * bit: the bit to update (CS_CPU_EXCLUSIVE, CS_MEM_EXCLUSIVE, - * CS_SCHED_LOAD_BALANCE, - * CS_NOTIFY_ON_RELEASE, CS_MEMORY_MIGRATE, - * CS_SPREAD_PAGE, CS_SPREAD_SLAB) - * cs: the cpuset to update - * buf: the buffer where we read the 0 or 1 - * - * Call with manage_mutex held. + * bit: the bit to update (see cpuset_flagbits_t) + * cs: the cpuset to update + * turning_on: whether the flag is being set or cleared + * + * Call with cgroup_mutex held. */ -static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, char *buf) +static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, + int turning_on) { - int turning_on; struct cpuset trialcs; int err; int cpus_nonempty, balance_flag_changed; - turning_on = (simple_strtoul(buf, NULL, 10) != 0); - trialcs = *cs; if (turning_on) set_bit(bit, &trialcs.flags); @@ -1200,6 +1184,7 @@ static int fmeter_getrate(struct fmeter *fmp) return val; } +/* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */ static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont, struct task_struct *tsk) { @@ -1223,7 +1208,7 @@ static void cpuset_attach(struct cgroup_subsys *ss, mutex_lock(&callback_mutex); guarantee_online_cpus(cs, &cpus); - set_cpus_allowed(tsk, cpus); + set_cpus_allowed_ptr(tsk, &cpus); mutex_unlock(&callback_mutex); from = oldcs->mems_allowed; @@ -1246,7 +1231,9 @@ typedef enum { FILE_MEMLIST, FILE_CPU_EXCLUSIVE, FILE_MEM_EXCLUSIVE, + FILE_MEM_HARDWALL, FILE_SCHED_LOAD_BALANCE, + FILE_SCHED_RELAX_DOMAIN_LEVEL, FILE_MEMORY_PRESSURE_ENABLED, FILE_MEMORY_PRESSURE, FILE_SPREAD_PAGE, @@ -1269,7 +1256,8 @@ static ssize_t cpuset_common_file_write(struct cgroup *cont, return -E2BIG; /* +1 for nul-terminator */ - if ((buffer = kmalloc(nbytes + 1, GFP_KERNEL)) == 0) + buffer = kmalloc(nbytes + 1, GFP_KERNEL); + if (!buffer) return -ENOMEM; if (copy_from_user(buffer, userbuf, nbytes)) { @@ -1292,43 +1280,71 @@ static ssize_t cpuset_common_file_write(struct cgroup *cont, case FILE_MEMLIST: retval = update_nodemask(cs, buffer); break; + case FILE_SCHED_RELAX_DOMAIN_LEVEL: + retval = update_relax_domain_level(cs, buffer); + break; + default: + retval = -EINVAL; + goto out2; + } + + if (retval == 0) + retval = nbytes; +out2: + cgroup_unlock(); +out1: + kfree(buffer); + return retval; +} + +static int cpuset_write_u64(struct cgroup *cgrp, struct cftype *cft, u64 val) +{ + int retval = 0; + struct cpuset *cs = cgroup_cs(cgrp); + cpuset_filetype_t type = cft->private; + + cgroup_lock(); + + if (cgroup_is_removed(cgrp)) { + cgroup_unlock(); + return -ENODEV; + } + + switch (type) { case FILE_CPU_EXCLUSIVE: - retval = update_flag(CS_CPU_EXCLUSIVE, cs, buffer); + retval = update_flag(CS_CPU_EXCLUSIVE, cs, val); break; case FILE_MEM_EXCLUSIVE: - retval = update_flag(CS_MEM_EXCLUSIVE, cs, buffer); + retval = update_flag(CS_MEM_EXCLUSIVE, cs, val); + break; + case FILE_MEM_HARDWALL: + retval = update_flag(CS_MEM_HARDWALL, cs, val); break; case FILE_SCHED_LOAD_BALANCE: - retval = update_flag(CS_SCHED_LOAD_BALANCE, cs, buffer); + retval = update_flag(CS_SCHED_LOAD_BALANCE, cs, val); break; case FILE_MEMORY_MIGRATE: - retval = update_flag(CS_MEMORY_MIGRATE, cs, buffer); + retval = update_flag(CS_MEMORY_MIGRATE, cs, val); break; case FILE_MEMORY_PRESSURE_ENABLED: - retval = update_memory_pressure_enabled(cs, buffer); + cpuset_memory_pressure_enabled = !!val; break; case FILE_MEMORY_PRESSURE: retval = -EACCES; break; case FILE_SPREAD_PAGE: - retval = update_flag(CS_SPREAD_PAGE, cs, buffer); + retval = update_flag(CS_SPREAD_PAGE, cs, val); cs->mems_generation = cpuset_mems_generation++; break; case FILE_SPREAD_SLAB: - retval = update_flag(CS_SPREAD_SLAB, cs, buffer); + retval = update_flag(CS_SPREAD_SLAB, cs, val); cs->mems_generation = cpuset_mems_generation++; break; default: retval = -EINVAL; - goto out2; + break; } - - if (retval == 0) - retval = nbytes; -out2: cgroup_unlock(); -out1: - kfree(buffer); return retval; } @@ -1390,29 +1406,8 @@ static ssize_t cpuset_common_file_read(struct cgroup *cont, case FILE_MEMLIST: s += cpuset_sprintf_memlist(s, cs); break; - case FILE_CPU_EXCLUSIVE: - *s++ = is_cpu_exclusive(cs) ? '1' : '0'; - break; - case FILE_MEM_EXCLUSIVE: - *s++ = is_mem_exclusive(cs) ? '1' : '0'; - break; - case FILE_SCHED_LOAD_BALANCE: - *s++ = is_sched_load_balance(cs) ? '1' : '0'; - break; - case FILE_MEMORY_MIGRATE: - *s++ = is_memory_migrate(cs) ? '1' : '0'; - break; - case FILE_MEMORY_PRESSURE_ENABLED: - *s++ = cpuset_memory_pressure_enabled ? '1' : '0'; - break; - case FILE_MEMORY_PRESSURE: - s += sprintf(s, "%d", fmeter_getrate(&cs->fmeter)); - break; - case FILE_SPREAD_PAGE: - *s++ = is_spread_page(cs) ? '1' : '0'; - break; - case FILE_SPREAD_SLAB: - *s++ = is_spread_slab(cs) ? '1' : '0'; + case FILE_SCHED_RELAX_DOMAIN_LEVEL: + s += sprintf(s, "%d", cs->relax_domain_level); break; default: retval = -EINVAL; @@ -1426,111 +1421,137 @@ out: return retval; } - - +static u64 cpuset_read_u64(struct cgroup *cont, struct cftype *cft) +{ + struct cpuset *cs = cgroup_cs(cont); + cpuset_filetype_t type = cft->private; + switch (type) { + case FILE_CPU_EXCLUSIVE: + return is_cpu_exclusive(cs); + case FILE_MEM_EXCLUSIVE: + return is_mem_exclusive(cs); + case FILE_MEM_HARDWALL: + return is_mem_hardwall(cs); + case FILE_SCHED_LOAD_BALANCE: + return is_sched_load_balance(cs); + case FILE_MEMORY_MIGRATE: + return is_memory_migrate(cs); + case FILE_MEMORY_PRESSURE_ENABLED: + return cpuset_memory_pressure_enabled; + case FILE_MEMORY_PRESSURE: + return fmeter_getrate(&cs->fmeter); + case FILE_SPREAD_PAGE: + return is_spread_page(cs); + case FILE_SPREAD_SLAB: + return is_spread_slab(cs); + default: + BUG(); + } +} /* * for the common functions, 'private' gives the type of file */ -static struct cftype cft_cpus = { - .name = "cpus", - .read = cpuset_common_file_read, - .write = cpuset_common_file_write, - .private = FILE_CPULIST, -}; - -static struct cftype cft_mems = { - .name = "mems", - .read = cpuset_common_file_read, - .write = cpuset_common_file_write, - .private = FILE_MEMLIST, -}; - -static struct cftype cft_cpu_exclusive = { - .name = "cpu_exclusive", - .read = cpuset_common_file_read, - .write = cpuset_common_file_write, - .private = FILE_CPU_EXCLUSIVE, -}; - -static struct cftype cft_mem_exclusive = { - .name = "mem_exclusive", - .read = cpuset_common_file_read, - .write = cpuset_common_file_write, - .private = FILE_MEM_EXCLUSIVE, -}; - -static struct cftype cft_sched_load_balance = { - .name = "sched_load_balance", - .read = cpuset_common_file_read, - .write = cpuset_common_file_write, - .private = FILE_SCHED_LOAD_BALANCE, -}; - -static struct cftype cft_memory_migrate = { - .name = "memory_migrate", - .read = cpuset_common_file_read, - .write = cpuset_common_file_write, - .private = FILE_MEMORY_MIGRATE, +static struct cftype files[] = { + { + .name = "cpus", + .read = cpuset_common_file_read, + .write = cpuset_common_file_write, + .private = FILE_CPULIST, + }, + + { + .name = "mems", + .read = cpuset_common_file_read, + .write = cpuset_common_file_write, + .private = FILE_MEMLIST, + }, + + { + .name = "cpu_exclusive", + .read_u64 = cpuset_read_u64, + .write_u64 = cpuset_write_u64, + .private = FILE_CPU_EXCLUSIVE, + }, + + { + .name = "mem_exclusive", + .read_u64 = cpuset_read_u64, + .write_u64 = cpuset_write_u64, + .private = FILE_MEM_EXCLUSIVE, + }, + + { + .name = "mem_hardwall", + .read_u64 = cpuset_read_u64, + .write_u64 = cpuset_write_u64, + .private = FILE_MEM_HARDWALL, + }, + + { + .name = "sched_load_balance", + .read_u64 = cpuset_read_u64, + .write_u64 = cpuset_write_u64, + .private = FILE_SCHED_LOAD_BALANCE, + }, + + { + .name = "sched_relax_domain_level", + .read_u64 = cpuset_read_u64, + .write_u64 = cpuset_write_u64, + .private = FILE_SCHED_RELAX_DOMAIN_LEVEL, + }, + + { + .name = "memory_migrate", + .read_u64 = cpuset_read_u64, + .write_u64 = cpuset_write_u64, + .private = FILE_MEMORY_MIGRATE, + }, + + { + .name = "memory_pressure", + .read_u64 = cpuset_read_u64, + .write_u64 = cpuset_write_u64, + .private = FILE_MEMORY_PRESSURE, + }, + + { + .name = "memory_spread_page", + .read_u64 = cpuset_read_u64, + .write_u64 = cpuset_write_u64, + .private = FILE_SPREAD_PAGE, + }, + + { + .name = "memory_spread_slab", + .read_u64 = cpuset_read_u64, + .write_u64 = cpuset_write_u64, + .private = FILE_SPREAD_SLAB, + }, }; static struct cftype cft_memory_pressure_enabled = { .name = "memory_pressure_enabled", - .read = cpuset_common_file_read, - .write = cpuset_common_file_write, + .read_u64 = cpuset_read_u64, + .write_u64 = cpuset_write_u64, .private = FILE_MEMORY_PRESSURE_ENABLED, }; -static struct cftype cft_memory_pressure = { - .name = "memory_pressure", - .read = cpuset_common_file_read, - .write = cpuset_common_file_write, - .private = FILE_MEMORY_PRESSURE, -}; - -static struct cftype cft_spread_page = { - .name = "memory_spread_page", - .read = cpuset_common_file_read, - .write = cpuset_common_file_write, - .private = FILE_SPREAD_PAGE, -}; - -static struct cftype cft_spread_slab = { - .name = "memory_spread_slab", - .read = cpuset_common_file_read, - .write = cpuset_common_file_write, - .private = FILE_SPREAD_SLAB, -}; - static int cpuset_populate(struct cgroup_subsys *ss, struct cgroup *cont) { int err; - if ((err = cgroup_add_file(cont, ss, &cft_cpus)) < 0) - return err; - if ((err = cgroup_add_file(cont, ss, &cft_mems)) < 0) - return err; - if ((err = cgroup_add_file(cont, ss, &cft_cpu_exclusive)) < 0) - return err; - if ((err = cgroup_add_file(cont, ss, &cft_mem_exclusive)) < 0) - return err; - if ((err = cgroup_add_file(cont, ss, &cft_memory_migrate)) < 0) - return err; - if ((err = cgroup_add_file(cont, ss, &cft_sched_load_balance)) < 0) - return err; - if ((err = cgroup_add_file(cont, ss, &cft_memory_pressure)) < 0) - return err; - if ((err = cgroup_add_file(cont, ss, &cft_spread_page)) < 0) - return err; - if ((err = cgroup_add_file(cont, ss, &cft_spread_slab)) < 0) + err = cgroup_add_files(cont, ss, files, ARRAY_SIZE(files)); + if (err) return err; /* memory_pressure_enabled is in root cpuset only */ - if (err == 0 && !cont->parent) + if (!cont->parent) err = cgroup_add_file(cont, ss, - &cft_memory_pressure_enabled); - return 0; + &cft_memory_pressure_enabled); + return err; } /* @@ -1547,7 +1568,8 @@ static int cpuset_populate(struct cgroup_subsys *ss, struct cgroup *cont) * If this becomes a problem for some users who wish to * allow that scenario, then cpuset_post_clone() could be * changed to grant parent->cpus_allowed-sibling_cpus_exclusive - * (and likewise for mems) to the new cgroup. + * (and likewise for mems) to the new cgroup. Called with cgroup_mutex + * held. */ static void cpuset_post_clone(struct cgroup_subsys *ss, struct cgroup *cgroup) @@ -1571,11 +1593,8 @@ static void cpuset_post_clone(struct cgroup_subsys *ss, /* * cpuset_create - create a cpuset - * parent: cpuset that will be parent of the new cpuset. - * name: name of the new cpuset. Will be strcpy'ed. - * mode: mode to set on new inode - * - * Must be called with the mutex on the parent inode held + * ss: cpuset cgroup subsystem + * cont: control group that the new cpuset will be part of */ static struct cgroup_subsys_state *cpuset_create( @@ -1602,10 +1621,11 @@ static struct cgroup_subsys_state *cpuset_create( if (is_spread_slab(parent)) set_bit(CS_SPREAD_SLAB, &cs->flags); set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags); - cs->cpus_allowed = CPU_MASK_NONE; - cs->mems_allowed = NODE_MASK_NONE; + cpus_clear(cs->cpus_allowed); + nodes_clear(cs->mems_allowed); cs->mems_generation = cpuset_mems_generation++; fmeter_init(&cs->fmeter); + cs->relax_domain_level = -1; cs->parent = parent; number_of_cpusets++; @@ -1617,10 +1637,10 @@ static struct cgroup_subsys_state *cpuset_create( * * If the cpuset being removed has its flag 'sched_load_balance' * enabled, then simulate turning sched_load_balance off, which - * will call rebuild_sched_domains(). The lock_cpu_hotplug() + * will call rebuild_sched_domains(). The get_online_cpus() * call in rebuild_sched_domains() must not be made while holding * callback_mutex. Elsewhere the kernel nests callback_mutex inside - * lock_cpu_hotplug() calls. So the reverse nesting would risk an + * get_online_cpus() calls. So the reverse nesting would risk an * ABBA deadlock. */ @@ -1631,7 +1651,7 @@ static void cpuset_destroy(struct cgroup_subsys *ss, struct cgroup *cont) cpuset_update_task_memory_state(); if (is_sched_load_balance(cs)) - update_flag(CS_SCHED_LOAD_BALANCE, cs, "0"); + update_flag(CS_SCHED_LOAD_BALANCE, cs, 0); number_of_cpusets--; kfree(cs); @@ -1672,12 +1692,13 @@ int __init cpuset_init(void) { int err = 0; - top_cpuset.cpus_allowed = CPU_MASK_ALL; - top_cpuset.mems_allowed = NODE_MASK_ALL; + cpus_setall(top_cpuset.cpus_allowed); + nodes_setall(top_cpuset.mems_allowed); fmeter_init(&top_cpuset.fmeter); top_cpuset.mems_generation = cpuset_mems_generation++; set_bit(CS_SCHED_LOAD_BALANCE, &top_cpuset.flags); + top_cpuset.relax_domain_level = -1; err = register_filesystem(&cpuset_fs_type); if (err < 0) @@ -1687,53 +1708,141 @@ int __init cpuset_init(void) return 0; } +/** + * cpuset_do_move_task - move a given task to another cpuset + * @tsk: pointer to task_struct the task to move + * @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner + * + * Called by cgroup_scan_tasks() for each task in a cgroup. + * Return nonzero to stop the walk through the tasks. + */ +static void cpuset_do_move_task(struct task_struct *tsk, + struct cgroup_scanner *scan) +{ + struct cpuset_hotplug_scanner *chsp; + + chsp = container_of(scan, struct cpuset_hotplug_scanner, scan); + cgroup_attach_task(chsp->to, tsk); +} + +/** + * move_member_tasks_to_cpuset - move tasks from one cpuset to another + * @from: cpuset in which the tasks currently reside + * @to: cpuset to which the tasks will be moved + * + * Called with cgroup_mutex held + * callback_mutex must not be held, as cpuset_attach() will take it. + * + * The cgroup_scan_tasks() function will scan all the tasks in a cgroup, + * calling callback functions for each. + */ +static void move_member_tasks_to_cpuset(struct cpuset *from, struct cpuset *to) +{ + struct cpuset_hotplug_scanner scan; + + scan.scan.cg = from->css.cgroup; + scan.scan.test_task = NULL; /* select all tasks in cgroup */ + scan.scan.process_task = cpuset_do_move_task; + scan.scan.heap = NULL; + scan.to = to->css.cgroup; + + if (cgroup_scan_tasks((struct cgroup_scanner *)&scan)) + printk(KERN_ERR "move_member_tasks_to_cpuset: " + "cgroup_scan_tasks failed\n"); +} + /* * If common_cpu_mem_hotplug_unplug(), below, unplugs any CPUs * or memory nodes, we need to walk over the cpuset hierarchy, * removing that CPU or node from all cpusets. If this removes the - * last CPU or node from a cpuset, then the guarantee_online_cpus() - * or guarantee_online_mems() code will use that emptied cpusets - * parent online CPUs or nodes. Cpusets that were already empty of - * CPUs or nodes are left empty. + * last CPU or node from a cpuset, then move the tasks in the empty + * cpuset to its next-highest non-empty parent. + * + * Called with cgroup_mutex held + * callback_mutex must not be held, as cpuset_attach() will take it. + */ +static void remove_tasks_in_empty_cpuset(struct cpuset *cs) +{ + struct cpuset *parent; + + /* + * The cgroup's css_sets list is in use if there are tasks + * in the cpuset; the list is empty if there are none; + * the cs->css.refcnt seems always 0. + */ + if (list_empty(&cs->css.cgroup->css_sets)) + return; + + /* + * Find its next-highest non-empty parent, (top cpuset + * has online cpus, so can't be empty). + */ + parent = cs->parent; + while (cpus_empty(parent->cpus_allowed) || + nodes_empty(parent->mems_allowed)) + parent = parent->parent; + + move_member_tasks_to_cpuset(cs, parent); +} + +/* + * Walk the specified cpuset subtree and look for empty cpusets. + * The tasks of such cpuset must be moved to a parent cpuset. * - * This routine is intentionally inefficient in a couple of regards. - * It will check all cpusets in a subtree even if the top cpuset of - * the subtree has no offline CPUs or nodes. It checks both CPUs and - * nodes, even though the caller could have been coded to know that - * only one of CPUs or nodes needed to be checked on a given call. - * This was done to minimize text size rather than cpu cycles. + * Called with cgroup_mutex held. We take callback_mutex to modify + * cpus_allowed and mems_allowed. * - * Call with both manage_mutex and callback_mutex held. + * This walk processes the tree from top to bottom, completing one layer + * before dropping down to the next. It always processes a node before + * any of its children. * - * Recursive, on depth of cpuset subtree. + * For now, since we lack memory hot unplug, we'll never see a cpuset + * that has tasks along with an empty 'mems'. But if we did see such + * a cpuset, we'd handle it just like we do if its 'cpus' was empty. */ - -static void guarantee_online_cpus_mems_in_subtree(const struct cpuset *cur) +static void scan_for_empty_cpusets(const struct cpuset *root) { + struct cpuset *cp; /* scans cpusets being updated */ + struct cpuset *child; /* scans child cpusets of cp */ + struct list_head queue; struct cgroup *cont; - struct cpuset *c; - /* Each of our child cpusets mems must be online */ - list_for_each_entry(cont, &cur->css.cgroup->children, sibling) { - c = cgroup_cs(cont); - guarantee_online_cpus_mems_in_subtree(c); - if (!cpus_empty(c->cpus_allowed)) - guarantee_online_cpus(c, &c->cpus_allowed); - if (!nodes_empty(c->mems_allowed)) - guarantee_online_mems(c, &c->mems_allowed); + INIT_LIST_HEAD(&queue); + + list_add_tail((struct list_head *)&root->stack_list, &queue); + + while (!list_empty(&queue)) { + cp = container_of(queue.next, struct cpuset, stack_list); + list_del(queue.next); + list_for_each_entry(cont, &cp->css.cgroup->children, sibling) { + child = cgroup_cs(cont); + list_add_tail(&child->stack_list, &queue); + } + cont = cp->css.cgroup; + + /* Continue past cpusets with all cpus, mems online */ + if (cpus_subset(cp->cpus_allowed, cpu_online_map) && + nodes_subset(cp->mems_allowed, node_states[N_HIGH_MEMORY])) + continue; + + /* Remove offline cpus and mems from this cpuset. */ + mutex_lock(&callback_mutex); + cpus_and(cp->cpus_allowed, cp->cpus_allowed, cpu_online_map); + nodes_and(cp->mems_allowed, cp->mems_allowed, + node_states[N_HIGH_MEMORY]); + mutex_unlock(&callback_mutex); + + /* Move tasks from the empty cpuset to a parent */ + if (cpus_empty(cp->cpus_allowed) || + nodes_empty(cp->mems_allowed)) + remove_tasks_in_empty_cpuset(cp); } } /* * The cpus_allowed and mems_allowed nodemasks in the top_cpuset track * cpu_online_map and node_states[N_HIGH_MEMORY]. Force the top cpuset to - * track what's online after any CPU or memory node hotplug or unplug - * event. - * - * To ensure that we don't remove a CPU or node from the top cpuset - * that is currently in use by a child cpuset (which would violate - * the rule that cpusets must be subsets of their parent), we first - * call the recursive routine guarantee_online_cpus_mems_in_subtree(). + * track what's online after any CPU or memory node hotplug or unplug event. * * Since there are two callers of this routine, one for CPU hotplug * events and one for memory node hotplug events, we could have coded @@ -1744,13 +1853,11 @@ static void guarantee_online_cpus_mems_in_subtree(const struct cpuset *cur) static void common_cpu_mem_hotplug_unplug(void) { cgroup_lock(); - mutex_lock(&callback_mutex); - guarantee_online_cpus_mems_in_subtree(&top_cpuset); top_cpuset.cpus_allowed = cpu_online_map; top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY]; + scan_for_empty_cpusets(&top_cpuset); - mutex_unlock(&callback_mutex); cgroup_unlock(); } @@ -1806,6 +1913,7 @@ void __init cpuset_init_smp(void) * cpuset_cpus_allowed - return cpus_allowed mask from a tasks cpuset. * @tsk: pointer to task_struct from which to obtain cpuset->cpus_allowed. + * @pmask: pointer to cpumask_t variable to receive cpus_allowed set. * * Description: Returns the cpumask_t cpus_allowed of the cpuset * attached to the specified @tsk. Guaranteed to return some non-empty @@ -1813,35 +1921,27 @@ void __init cpuset_init_smp(void) * tasks cpuset. **/ -cpumask_t cpuset_cpus_allowed(struct task_struct *tsk) +void cpuset_cpus_allowed(struct task_struct *tsk, cpumask_t *pmask) { - cpumask_t mask; - mutex_lock(&callback_mutex); - mask = cpuset_cpus_allowed_locked(tsk); + cpuset_cpus_allowed_locked(tsk, pmask); mutex_unlock(&callback_mutex); - - return mask; } /** * cpuset_cpus_allowed_locked - return cpus_allowed mask from a tasks cpuset. - * Must be called with callback_mutex held. + * Must be called with callback_mutex held. **/ -cpumask_t cpuset_cpus_allowed_locked(struct task_struct *tsk) +void cpuset_cpus_allowed_locked(struct task_struct *tsk, cpumask_t *pmask) { - cpumask_t mask; - task_lock(tsk); - guarantee_online_cpus(task_cs(tsk), &mask); + guarantee_online_cpus(task_cs(tsk), pmask); task_unlock(tsk); - - return mask; } void cpuset_init_current_mems_allowed(void) { - current->mems_allowed = NODE_MASK_ALL; + nodes_setall(current->mems_allowed); } /** @@ -1868,33 +1968,25 @@ nodemask_t cpuset_mems_allowed(struct task_struct *tsk) } /** - * cpuset_zonelist_valid_mems_allowed - check zonelist vs. curremt mems_allowed - * @zl: the zonelist to be checked + * cpuset_nodemask_valid_mems_allowed - check nodemask vs. curremt mems_allowed + * @nodemask: the nodemask to be checked * - * Are any of the nodes on zonelist zl allowed in current->mems_allowed? + * Are any of the nodes in the nodemask allowed in current->mems_allowed? */ -int cpuset_zonelist_valid_mems_allowed(struct zonelist *zl) +int cpuset_nodemask_valid_mems_allowed(nodemask_t *nodemask) { - int i; - - for (i = 0; zl->zones[i]; i++) { - int nid = zone_to_nid(zl->zones[i]); - - if (node_isset(nid, current->mems_allowed)) - return 1; - } - return 0; + return nodes_intersects(*nodemask, current->mems_allowed); } /* - * nearest_exclusive_ancestor() - Returns the nearest mem_exclusive - * ancestor to the specified cpuset. Call holding callback_mutex. - * If no ancestor is mem_exclusive (an unusual configuration), then - * returns the root cpuset. + * nearest_hardwall_ancestor() - Returns the nearest mem_exclusive or + * mem_hardwall ancestor to the specified cpuset. Call holding + * callback_mutex. If no ancestor is mem_exclusive or mem_hardwall + * (an unusual configuration), then returns the root cpuset. */ -static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs) +static const struct cpuset *nearest_hardwall_ancestor(const struct cpuset *cs) { - while (!is_mem_exclusive(cs) && cs->parent) + while (!(is_mem_exclusive(cs) || is_mem_hardwall(cs)) && cs->parent) cs = cs->parent; return cs; } @@ -1908,7 +2000,7 @@ static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs) * __GFP_THISNODE is set, yes, we can always allocate. If zone * z's node is in our tasks mems_allowed, yes. If it's not a * __GFP_HARDWALL request and this zone's nodes is in the nearest - * mem_exclusive cpuset ancestor to this tasks cpuset, yes. + * hardwalled cpuset ancestor to this tasks cpuset, yes. * If the task has been OOM killed and has access to memory reserves * as specified by the TIF_MEMDIE flag, yes. * Otherwise, no. @@ -1931,7 +2023,7 @@ static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs) * and do not allow allocations outside the current tasks cpuset * unless the task has been OOM killed as is marked TIF_MEMDIE. * GFP_KERNEL allocations are not so marked, so can escape to the - * nearest enclosing mem_exclusive ancestor cpuset. + * nearest enclosing hardwalled ancestor cpuset. * * Scanning up parent cpusets requires callback_mutex. The * __alloc_pages() routine only calls here with __GFP_HARDWALL bit @@ -1954,7 +2046,7 @@ static const struct cpuset *nearest_exclusive_ancestor(const struct cpuset *cs) * in_interrupt - any node ok (current task context irrelevant) * GFP_ATOMIC - any node ok * TIF_MEMDIE - any node ok - * GFP_KERNEL - any node in enclosing mem_exclusive cpuset ok + * GFP_KERNEL - any node in enclosing hardwalled cpuset ok * GFP_USER - only nodes in current tasks mems allowed ok. * * Rule: @@ -1991,7 +2083,7 @@ int __cpuset_zone_allowed_softwall(struct zone *z, gfp_t gfp_mask) mutex_lock(&callback_mutex); task_lock(current); - cs = nearest_exclusive_ancestor(task_cs(current)); + cs = nearest_hardwall_ancestor(task_cs(current)); task_unlock(current); allowed = node_isset(node, cs->mems_allowed); @@ -2163,10 +2255,8 @@ void __cpuset_memory_pressure_bump(void) * - Used for /proc//cpuset. * - No need to task_lock(tsk) on this tsk->cpuset reference, as it * doesn't really matter if tsk->cpuset changes after we read it, - * and we take manage_mutex, keeping attach_task() from changing it - * anyway. No need to check that tsk->cpuset != NULL, thanks to - * the_top_cpuset_hack in cpuset_exit(), which sets an exiting tasks - * cpuset to top_cpuset. + * and we take cgroup_mutex, keeping cpuset_attach() from changing it + * anyway. */ static int proc_cpuset_show(struct seq_file *m, void *unused_v) { @@ -2219,13 +2309,22 @@ const struct file_operations proc_cpuset_operations = { #endif /* CONFIG_PROC_PID_CPUSET */ /* Display task cpus_allowed, mems_allowed in /proc//status file. */ -char *cpuset_task_status_allowed(struct task_struct *task, char *buffer) -{ - buffer += sprintf(buffer, "Cpus_allowed:\t"); - buffer += cpumask_scnprintf(buffer, PAGE_SIZE, task->cpus_allowed); - buffer += sprintf(buffer, "\n"); - buffer += sprintf(buffer, "Mems_allowed:\t"); - buffer += nodemask_scnprintf(buffer, PAGE_SIZE, task->mems_allowed); - buffer += sprintf(buffer, "\n"); - return buffer; +void cpuset_task_status_allowed(struct seq_file *m, struct task_struct *task) +{ + seq_printf(m, "Cpus_allowed:\t"); + m->count += cpumask_scnprintf(m->buf + m->count, m->size - m->count, + task->cpus_allowed); + seq_printf(m, "\n"); + seq_printf(m, "Cpus_allowed_list:\t"); + m->count += cpulist_scnprintf(m->buf + m->count, m->size - m->count, + task->cpus_allowed); + seq_printf(m, "\n"); + seq_printf(m, "Mems_allowed:\t"); + m->count += nodemask_scnprintf(m->buf + m->count, m->size - m->count, + task->mems_allowed); + seq_printf(m, "\n"); + seq_printf(m, "Mems_allowed_list:\t"); + m->count += nodelist_scnprintf(m->buf + m->count, m->size - m->count, + task->mems_allowed); + seq_printf(m, "\n"); }