clockevents: introduce force broadcast notifier

[linux-2.6-omap-h63xx.git] / kernel / cpuset.c

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index e6d002fc73928f4aac978a95b9386d74dbb7d9a6..57e6448b171e9ff277a85bdf02d061ea8cac7623 100644 (file)
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -516,7 +516,7 @@ static void cpuset_release_agent(const char *pathbuf)
        envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
        envp[i] = NULL;
 
-       call_usermodehelper(argv[0], argv, envp, 0);
+       call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
        kfree(pathbuf);
 }
 
@@ -821,11 +821,22 @@ static int update_cpumask(struct cpuset *cs, char *buf)
                return -EACCES;
 
        trialcs = *cs;
-       retval = cpulist_parse(buf, trialcs.cpus_allowed);
-       if (retval < 0)
-               return retval;
+
+       /*
+        * We allow a cpuset's cpus_allowed to be empty; if it has attached
+        * tasks, we'll catch it later when we validate the change and return
+        * -ENOSPC.
+        */
+       if (!buf[0] || (buf[0] == '\n' && !buf[1])) {
+               cpus_clear(trialcs.cpus_allowed);
+       } else {
+               retval = cpulist_parse(buf, trialcs.cpus_allowed);
+               if (retval < 0)
+                       return retval;
+       }
        cpus_and(trialcs.cpus_allowed, trialcs.cpus_allowed, cpu_online_map);
-       if (cpus_empty(trialcs.cpus_allowed))
+       /* cpus_allowed cannot be empty for a cpuset with attached tasks. */
+       if (atomic_read(&cs->count) && cpus_empty(trialcs.cpus_allowed))
                return -ENOSPC;
        retval = validate_change(cs, &trialcs);
        if (retval < 0)
@@ -918,16 +929,27 @@ static int update_nodemask(struct cpuset *cs, char *buf)
                return -EACCES;
 
        trialcs = *cs;
-       retval = nodelist_parse(buf, trialcs.mems_allowed);
-       if (retval < 0)
-               goto done;
+
+       /*
+        * We allow a cpuset's mems_allowed to be empty; if it has attached
+        * tasks, we'll catch it later when we validate the change and return
+        * -ENOSPC.
+        */
+       if (!buf[0] || (buf[0] == '\n' && !buf[1])) {
+               nodes_clear(trialcs.mems_allowed);
+       } else {
+               retval = nodelist_parse(buf, trialcs.mems_allowed);
+               if (retval < 0)
+                       goto done;
+       }
        nodes_and(trialcs.mems_allowed, trialcs.mems_allowed, node_online_map);
        oldmem = cs->mems_allowed;
        if (nodes_equal(oldmem, trialcs.mems_allowed)) {
                retval = 0;             /* Too easy - nothing to do */
                goto done;
        }
-       if (nodes_empty(trialcs.mems_allowed)) {
+       /* mems_allowed cannot be empty for a cpuset with attached tasks. */
+       if (atomic_read(&cs->count) && nodes_empty(trialcs.mems_allowed)) {
                retval = -ENOSPC;
                goto done;
        }
@@ -959,10 +981,10 @@ static int update_nodemask(struct cpuset *cs, char *buf)
                mmarray = kmalloc(ntasks * sizeof(*mmarray), GFP_KERNEL);
                if (!mmarray)
                        goto done;
-               write_lock_irq(&tasklist_lock);         /* block fork */
+               read_lock(&tasklist_lock);              /* block fork */
                if (atomic_read(&cs->count) <= ntasks)
                        break;                          /* got enough */
-               write_unlock_irq(&tasklist_lock);       /* try again */
+               read_unlock(&tasklist_lock);            /* try again */
                kfree(mmarray);
        }
 
@@ -984,7 +1006,7 @@ static int update_nodemask(struct cpuset *cs, char *buf)
                        continue;
                mmarray[n++] = mm;
        } while_each_thread(g, p);
-       write_unlock_irq(&tasklist_lock);
+       read_unlock(&tasklist_lock);
 
        /*
         * Now that we've dropped the tasklist spinlock, we can
@@ -1660,9 +1682,9 @@ static int pid_array_load(pid_t *pidarray, int npids, struct cpuset *cs)
 
        do_each_thread(g, p) {
                if (p->cpuset == cs) {
-                       pidarray[n++] = p->pid;
                        if (unlikely(n == npids))
                                goto array_full;
+                       pidarray[n++] = p->pid;
                }
        } while_each_thread(g, p);
 
@@ -1750,12 +1772,7 @@ static ssize_t cpuset_tasks_read(struct file *file, char __user *buf,
 {
        struct ctr_struct *ctr = file->private_data;
 
-       if (*ppos + nbytes > ctr->bufsz)
-               nbytes = ctr->bufsz - *ppos;
-       if (copy_to_user(buf, ctr->buf + *ppos, nbytes))
-               return -EFAULT;
-       *ppos += nbytes;
-       return nbytes;
+       return simple_read_from_buffer(buf, nbytes, ppos, ctr->buf, ctr->bufsz);
 }
 
 static int cpuset_tasks_release(struct inode *unused_inode, struct file *file)
@@ -2121,6 +2138,9 @@ static void common_cpu_mem_hotplug_unplug(void)
 static int cpuset_handle_cpuhp(struct notifier_block *nb,
                                unsigned long phase, void *cpu)
 {
+       if (phase == CPU_DYING || phase == CPU_DYING_FROZEN)
+               return NOTIFY_DONE;
+
        common_cpu_mem_hotplug_unplug();
        return 0;
 }