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authorIngo Molnar <mingo@elte.hu>2012-01-08 12:31:24 +0100
committerIngo Molnar <mingo@elte.hu>2012-01-08 12:31:24 +0100
commit636f0c70f2557e0819b50c74e31b4a027327015e (patch)
tree3a259ef26659dac92782651440091b9f5ab1a7f7 /kernel
parent675eef66e3edcab8065533edfefbcbbacb9a30d3 (diff)
parent2e885057b7f75035f0b85e02f737891482815a81 (diff)
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Merge branch 'tip/perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup.c5
-rw-r--r--kernel/cpuset.c29
-rw-r--r--kernel/events/core.c8
-rw-r--r--kernel/exit.c9
-rw-r--r--kernel/futex.c28
-rw-r--r--kernel/hung_task.c14
-rw-r--r--kernel/ptrace.c13
-rw-r--r--kernel/sched_fair.c14
-rw-r--r--kernel/signal.c2
-rw-r--r--kernel/sysctl_binary.c2
-rw-r--r--kernel/time/clockevents.c1
-rw-r--r--kernel/time/clocksource.c12
12 files changed, 98 insertions, 39 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index d9d5648f3cdc..a184470cf9b5 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2098,11 +2098,6 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
continue;
/* get old css_set pointer */
task_lock(tsk);
- if (tsk->flags & PF_EXITING) {
- /* ignore this task if it's going away */
- task_unlock(tsk);
- continue;
- }
oldcg = tsk->cgroups;
get_css_set(oldcg);
task_unlock(tsk);
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 9fe58c46a426..0b1712dba587 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -123,6 +123,19 @@ static inline struct cpuset *task_cs(struct task_struct *task)
struct cpuset, css);
}
+#ifdef CONFIG_NUMA
+static inline bool task_has_mempolicy(struct task_struct *task)
+{
+ return task->mempolicy;
+}
+#else
+static inline bool task_has_mempolicy(struct task_struct *task)
+{
+ return false;
+}
+#endif
+
+
/* bits in struct cpuset flags field */
typedef enum {
CS_CPU_EXCLUSIVE,
@@ -949,7 +962,7 @@ static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from,
static void cpuset_change_task_nodemask(struct task_struct *tsk,
nodemask_t *newmems)
{
- bool masks_disjoint = !nodes_intersects(*newmems, tsk->mems_allowed);
+ bool need_loop;
repeat:
/*
@@ -962,6 +975,14 @@ repeat:
return;
task_lock(tsk);
+ /*
+ * Determine if a loop is necessary if another thread is doing
+ * get_mems_allowed(). If at least one node remains unchanged and
+ * tsk does not have a mempolicy, then an empty nodemask will not be
+ * possible when mems_allowed is larger than a word.
+ */
+ need_loop = task_has_mempolicy(tsk) ||
+ !nodes_intersects(*newmems, tsk->mems_allowed);
nodes_or(tsk->mems_allowed, tsk->mems_allowed, *newmems);
mpol_rebind_task(tsk, newmems, MPOL_REBIND_STEP1);
@@ -981,11 +1002,9 @@ repeat:
/*
* Allocation of memory is very fast, we needn't sleep when waiting
- * for the read-side. No wait is necessary, however, if at least one
- * node remains unchanged.
+ * for the read-side.
*/
- while (masks_disjoint &&
- ACCESS_ONCE(tsk->mems_allowed_change_disable)) {
+ while (need_loop && ACCESS_ONCE(tsk->mems_allowed_change_disable)) {
task_unlock(tsk);
if (!task_curr(tsk))
yield();
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 2f8f3f103cb4..24e3a4b1c89c 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3360,9 +3360,13 @@ static void ring_buffer_wakeup(struct perf_event *event)
rcu_read_lock();
rb = rcu_dereference(event->rb);
- list_for_each_entry_rcu(event, &rb->event_list, rb_entry) {
+ if (!rb)
+ goto unlock;
+
+ list_for_each_entry_rcu(event, &rb->event_list, rb_entry)
wake_up_all(&event->waitq);
- }
+
+unlock:
rcu_read_unlock();
}
diff --git a/kernel/exit.c b/kernel/exit.c
index d0b7d988f873..e6e01b959a0e 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1540,8 +1540,15 @@ static int wait_consider_task(struct wait_opts *wo, int ptrace,
}
/* dead body doesn't have much to contribute */
- if (p->exit_state == EXIT_DEAD)
+ if (unlikely(p->exit_state == EXIT_DEAD)) {
+ /*
+ * But do not ignore this task until the tracer does
+ * wait_task_zombie()->do_notify_parent().
+ */
+ if (likely(!ptrace) && unlikely(ptrace_reparented(p)))
+ wo->notask_error = 0;
return 0;
+ }
/* slay zombie? */
if (p->exit_state == EXIT_ZOMBIE) {
diff --git a/kernel/futex.c b/kernel/futex.c
index ea87f4d2f455..1614be20173d 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -314,17 +314,29 @@ again:
#endif
lock_page(page_head);
+
+ /*
+ * If page_head->mapping is NULL, then it cannot be a PageAnon
+ * page; but it might be the ZERO_PAGE or in the gate area or
+ * in a special mapping (all cases which we are happy to fail);
+ * or it may have been a good file page when get_user_pages_fast
+ * found it, but truncated or holepunched or subjected to
+ * invalidate_complete_page2 before we got the page lock (also
+ * cases which we are happy to fail). And we hold a reference,
+ * so refcount care in invalidate_complete_page's remove_mapping
+ * prevents drop_caches from setting mapping to NULL beneath us.
+ *
+ * The case we do have to guard against is when memory pressure made
+ * shmem_writepage move it from filecache to swapcache beneath us:
+ * an unlikely race, but we do need to retry for page_head->mapping.
+ */
if (!page_head->mapping) {
+ int shmem_swizzled = PageSwapCache(page_head);
unlock_page(page_head);
put_page(page_head);
- /*
- * ZERO_PAGE pages don't have a mapping. Avoid a busy loop
- * trying to find one. RW mapping would have COW'd (and thus
- * have a mapping) so this page is RO and won't ever change.
- */
- if ((page_head == ZERO_PAGE(address)))
- return -EFAULT;
- goto again;
+ if (shmem_swizzled)
+ goto again;
+ return -EFAULT;
}
/*
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 8b1748d0172c..2e48ec0c2e91 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -74,11 +74,17 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
/*
* Ensure the task is not frozen.
- * Also, when a freshly created task is scheduled once, changes
- * its state to TASK_UNINTERRUPTIBLE without having ever been
- * switched out once, it musn't be checked.
+ * Also, skip vfork and any other user process that freezer should skip.
*/
- if (unlikely(t->flags & PF_FROZEN || !switch_count))
+ if (unlikely(t->flags & (PF_FROZEN | PF_FREEZER_SKIP)))
+ return;
+
+ /*
+ * When a freshly created task is scheduled once, changes its state to
+ * TASK_UNINTERRUPTIBLE without having ever been switched out once, it
+ * musn't be checked.
+ */
+ if (unlikely(!switch_count))
return;
if (switch_count != t->last_switch_count) {
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 24d04477b257..78ab24a7b0e4 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -96,9 +96,20 @@ void __ptrace_unlink(struct task_struct *child)
*/
if (!(child->flags & PF_EXITING) &&
(child->signal->flags & SIGNAL_STOP_STOPPED ||
- child->signal->group_stop_count))
+ child->signal->group_stop_count)) {
child->jobctl |= JOBCTL_STOP_PENDING;
+ /*
+ * This is only possible if this thread was cloned by the
+ * traced task running in the stopped group, set the signal
+ * for the future reports.
+ * FIXME: we should change ptrace_init_task() to handle this
+ * case.
+ */
+ if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
+ child->jobctl |= SIGSTOP;
+ }
+
/*
* If transition to TASK_STOPPED is pending or in TASK_TRACED, kick
* @child in the butt. Note that @resume should be used iff @child
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index a78ed2736ba7..8a39fa3e3c6c 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -2352,13 +2352,11 @@ again:
if (!smt && (sd->flags & SD_SHARE_CPUPOWER))
continue;
- if (!(sd->flags & SD_SHARE_PKG_RESOURCES)) {
- if (!smt) {
- smt = 1;
- goto again;
- }
+ if (smt && !(sd->flags & SD_SHARE_CPUPOWER))
+ break;
+
+ if (!(sd->flags & SD_SHARE_PKG_RESOURCES))
break;
- }
sg = sd->groups;
do {
@@ -2378,6 +2376,10 @@ next:
sg = sg->next;
} while (sg != sd->groups);
}
+ if (!smt) {
+ smt = 1;
+ goto again;
+ }
done:
rcu_read_unlock();
diff --git a/kernel/signal.c b/kernel/signal.c
index b3f78d09a105..206551563cce 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1994,8 +1994,6 @@ static bool do_signal_stop(int signr)
*/
if (!(sig->flags & SIGNAL_STOP_STOPPED))
sig->group_exit_code = signr;
- else
- WARN_ON_ONCE(!current->ptrace);
sig->group_stop_count = 0;
diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index 6318b511afa1..a650694883a1 100644
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -1354,7 +1354,7 @@ static ssize_t binary_sysctl(const int *name, int nlen,
fput(file);
out_putname:
- putname(pathname);
+ __putname(pathname);
out:
return result;
}
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index c4eb71c8b2ea..1ecd6ba36d6c 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -387,7 +387,6 @@ void clockevents_exchange_device(struct clock_event_device *old,
* released list and do a notify add later.
*/
if (old) {
- old->event_handler = clockevents_handle_noop;
clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED);
list_del(&old->list);
list_add(&old->list, &clockevents_released);
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index da2f760e780c..d3ad022136e5 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -647,7 +647,7 @@ static void clocksource_enqueue(struct clocksource *cs)
/**
* __clocksource_updatefreq_scale - Used update clocksource with new freq
- * @t: clocksource to be registered
+ * @cs: clocksource to be registered
* @scale: Scale factor multiplied against freq to get clocksource hz
* @freq: clocksource frequency (cycles per second) divided by scale
*
@@ -699,7 +699,7 @@ EXPORT_SYMBOL_GPL(__clocksource_updatefreq_scale);
/**
* __clocksource_register_scale - Used to install new clocksources
- * @t: clocksource to be registered
+ * @cs: clocksource to be registered
* @scale: Scale factor multiplied against freq to get clocksource hz
* @freq: clocksource frequency (cycles per second) divided by scale
*
@@ -727,7 +727,7 @@ EXPORT_SYMBOL_GPL(__clocksource_register_scale);
/**
* clocksource_register - Used to install new clocksources
- * @t: clocksource to be registered
+ * @cs: clocksource to be registered
*
* Returns -EBUSY if registration fails, zero otherwise.
*/
@@ -761,6 +761,8 @@ static void __clocksource_change_rating(struct clocksource *cs, int rating)
/**
* clocksource_change_rating - Change the rating of a registered clocksource
+ * @cs: clocksource to be changed
+ * @rating: new rating
*/
void clocksource_change_rating(struct clocksource *cs, int rating)
{
@@ -772,6 +774,7 @@ EXPORT_SYMBOL(clocksource_change_rating);
/**
* clocksource_unregister - remove a registered clocksource
+ * @cs: clocksource to be unregistered
*/
void clocksource_unregister(struct clocksource *cs)
{
@@ -787,6 +790,7 @@ EXPORT_SYMBOL(clocksource_unregister);
/**
* sysfs_show_current_clocksources - sysfs interface for current clocksource
* @dev: unused
+ * @attr: unused
* @buf: char buffer to be filled with clocksource list
*
* Provides sysfs interface for listing current clocksource.
@@ -807,6 +811,7 @@ sysfs_show_current_clocksources(struct sys_device *dev,
/**
* sysfs_override_clocksource - interface for manually overriding clocksource
* @dev: unused
+ * @attr: unused
* @buf: name of override clocksource
* @count: length of buffer
*
@@ -842,6 +847,7 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
/**
* sysfs_show_available_clocksources - sysfs interface for listing clocksource
* @dev: unused
+ * @attr: unused
* @buf: char buffer to be filled with clocksource list
*
* Provides sysfs interface for listing registered clocksources