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Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

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* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf tools: Fix time function double declaration with glibc
  perf tools: Fix build by checking if extra warnings are supported
  perf tools: Fix build when using gcc 3.4.6
  perf tools: Add missing header, fixes build
  perf tools: Fix 64 bit integer format strings
  perf test: Fix build on older glibcs
  perf: perf_event_exit_task_context: s/rcu_dereference/rcu_dereference_raw/
  perf test: Use cpu_map->[cpu] when setting affinity
  perf symbols: Fix annotation of thumb code
  perf: Annotate cpuctx->ctx.mutex to avoid a lockdep splat
  powerpc, perf: Fix frequency calculation for overflowing counters (FSL version)
  perf: Fix perf_event_init_task()/perf_event_free_task() interaction
  perf: Fix find_get_context() vs perf_event_exit_task() race
This commit is contained in:
Linus Torvalds
2011-01-25 05:26:47 +10:00
parent ce84d539ce 00e99a49f6
commit 500d85ce39
28 changed files with 164 additions and 121 deletions
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46
kernel/perf_event.c
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@@ -2201,13 +2201,6 @@ find_lively_task_by_vpid(pid_t vpid)
if (!task)
return ERR_PTR(-ESRCH);
/*
* Can't attach events to a dying task.
*/
err = -ESRCH;
if (task->flags & PF_EXITING)
goto errout;
/* Reuse ptrace permission checks for now. */
err = -EACCES;
if (!ptrace_may_access(task, PTRACE_MODE_READ))
@@ -2268,14 +2261,27 @@ retry:
get_ctx(ctx);
if (cmpxchg(&task->perf_event_ctxp[ctxn], NULL, ctx)) {
/*
* We raced with some other task; use
* the context they set.
*/
err = 0;
mutex_lock(&task->perf_event_mutex);
/*
* If it has already passed perf_event_exit_task().
* we must see PF_EXITING, it takes this mutex too.
*/
if (task->flags & PF_EXITING)
err = -ESRCH;
else if (task->perf_event_ctxp[ctxn])
err = -EAGAIN;
else
rcu_assign_pointer(task->perf_event_ctxp[ctxn], ctx);
mutex_unlock(&task->perf_event_mutex);
if (unlikely(err)) {
put_task_struct(task);
kfree(ctx);
goto retry;
if (err == -EAGAIN)
goto retry;
goto errout;
}
}
@@ -5374,6 +5380,8 @@ free_dev:
goto out;
}
static struct lock_class_key cpuctx_mutex;
int perf_pmu_register(struct pmu *pmu, char *name, int type)
{
int cpu, ret;
@@ -5422,6 +5430,7 @@ skip_type:
cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
__perf_event_init_context(&cpuctx->ctx);
lockdep_set_class(&cpuctx->ctx.mutex, &cpuctx_mutex);
cpuctx->ctx.type = cpu_context;
cpuctx->ctx.pmu = pmu;
cpuctx->jiffies_interval = 1;
@@ -6127,7 +6136,7 @@ static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
* scheduled, so we are now safe from rescheduling changing
* our context.
*/
child_ctx = child->perf_event_ctxp[ctxn];
child_ctx = rcu_dereference_raw(child->perf_event_ctxp[ctxn]);
task_ctx_sched_out(child_ctx, EVENT_ALL);
/*
@@ -6440,11 +6449,6 @@ int perf_event_init_context(struct task_struct *child, int ctxn)
unsigned long flags;
int ret = 0;
child->perf_event_ctxp[ctxn] = NULL;
mutex_init(&child->perf_event_mutex);
INIT_LIST_HEAD(&child->perf_event_list);
if (likely(!parent->perf_event_ctxp[ctxn]))
return 0;
@@ -6533,6 +6537,10 @@ int perf_event_init_task(struct task_struct *child)
{
int ctxn, ret;
memset(child->perf_event_ctxp, 0, sizeof(child->perf_event_ctxp));
mutex_init(&child->perf_event_mutex);
INIT_LIST_HEAD(&child->perf_event_list);
for_each_task_context_nr(ctxn) {
ret = perf_event_init_context(child, ctxn);
if (ret)