Create a torture_param() macro and apply it to rcutorture in order to
save a few lines of code. This same macro may be applied to other
torture frameworks.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Because rcu_torture_random() will be used by the locking equivalent to
rcutorture, pull it out into its own module. This new module cannot
be separately configured, instead, use the Kconfig "select" statement
from the Kconfig options of tests depending on it.
Suggested-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit does a code-style cleanup so that the first curly brace
of an initializer does not appear at the beginning of a line.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The user explicitly disabled load balancing, else this core would not be
disconnected. Don't add these to nohz.idle_cpus_mask.
Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Lei Wen <leiwen@marvell.com>
Link: http://lkml.kernel.org/n/tip-vmme4f49psirp966pklm5l9j@git.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This is a leftover from commit e23ee74777
("sched/rt: Simplify pull_rt_task() logic and remove .leaf_rt_rq_list").
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/52F5CBF6.4060901@huawei.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If a PI boosted task policy/priority is modified by a setscheduler()
call we unconditionally dequeue and requeue the task if it is on the
runqueue even if the new priority is lower than the current effective
boosted priority. This can result in undesired reordering of the
priority bucket list.
If the new priority is less or equal than the current effective we
just store the new parameters in the task struct and leave the
scheduler class and the runqueue untouched. This is handled when the
task deboosts itself. Only if the new priority is higher than the
effective boosted priority we apply the change immediately.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[ Rebase ontop of v3.14-rc1. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Dario Faggioli <raistlin@linux.it>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1391803122-4425-7-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The following scenario does not work correctly:
Runqueue of CPUx contains two runnable and pinned tasks:
T1: SCHED_FIFO, prio 80
T2: SCHED_FIFO, prio 80
T1 is on the cpu and executes the following syscalls (classic priority
ceiling scenario):
sys_sched_setscheduler(pid(T1), SCHED_FIFO, .prio = 90);
...
sys_sched_setscheduler(pid(T1), SCHED_FIFO, .prio = 80);
...
Now T1 gets preempted by T3 (SCHED_FIFO, prio 95). After T3 goes back
to sleep the scheduler picks T2. Surprise!
The same happens w/o actual preemption when T1 is forced into the
scheduler due to a sporadic NEED_RESCHED event. The scheduler invokes
pick_next_task() which returns T2. So T1 gets preempted and scheduled
out.
This happens because sched_setscheduler() dequeues T1 from the prio 90
list and then enqueues it on the tail of the prio 80 list behind T2.
This violates the POSIX spec and surprises user space which relies on
the guarantee that SCHED_FIFO tasks are not scheduled out unless they
give the CPU up voluntarily or are preempted by a higher priority
task. In the latter case the preempted task must get back on the CPU
after the preempting task schedules out again.
We fixed a similar issue already in commit 60db48c (sched: Queue a
deboosted task to the head of the RT prio queue). The same treatment
is necessary for sched_setscheduler(). So enqueue to head of the prio
bucket list if the priority of the task is lowered.
It might be possible that existing user space relies on the current
behaviour, but it can be considered highly unlikely due to the corner
case nature of the application scenario.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1391803122-4425-6-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If the policy and priority remain unchanged a possible modification of
p->sched_reset_on_fork gets lost in the early exit path.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[ Rebase ontop of v3.14-rc1. ]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1391803122-4425-5-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
might_sleep() can tell us where interrupts have been disabled, but we
have no idea what disabled preemption. Add some debug infrastructure.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1391803122-4425-4-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Idle is not allowed to call sleeping functions ever!
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1391803122-4425-3-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We stumbled in RT over a SMP bringup issue on ARM where the
idle->on_rq == 0 was causing try_to_wakeup() on the other cpu to run
into nada land.
After adding that idle->on_rq = 1; I was able to find the root cause
of the lockup: the idle task on the newly woken up cpu was fiddling
with a sleeping spinlock, which is a nono.
I kept the init of idle->on_rq to keep the state consistent and to
avoid another long lasting debug session.
As a side note, the whole debug mess could have been avoided if
might_sleep() would have yelled when called from the idle task. That's
fixed with patch 2/6 - and that one actually has a changelog :)
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1391803122-4425-2-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On Mon, Feb 10, 2014 at 08:45:16AM -0800, Dave Hansen wrote:
> The reason I coded this up was that NMIs were firing off so fast that
> nothing else was getting a chance to run. With this patch, at least the
> printk() would come out and I'd have some idea what was going on.
It will start spewing to early_printk() (which is a lot nicer to use
from NMI context too) when it fails to queue the IRQ-work because its
already enqueued.
It does have the false-positive for when two CPUs trigger the warn
concurrently, but that should be rare and some extra clutter on the
early printk shouldn't be a problem.
Cc: hpa@zytor.com
Cc: tglx@linutronix.de
Cc: dzickus@redhat.com
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: mingo@kernel.org
Fixes: 6a02ad66b2 ("perf/x86: Push the duration-logging printk() to IRQ context")
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140211150116.GO27965@twins.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Remove a few gratuitous #ifdefs in pick_next_task*().
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-nnzddp5c4fijyzzxxrwlxghf@git.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Dan Carpenter reported:
> kernel/sched/rt.c:1347 pick_next_task_rt() warn: variable dereferenced before check 'prev' (see line 1338)
> kernel/sched/deadline.c:1011 pick_next_task_dl() warn: variable dereferenced before check 'prev' (see line 1005)
Kirill also spotted that migrate_tasks() will have an instant NULL
deref because pick_next_task() will immediately deref prev.
Instead of fixing all the corner cases because migrate_tasks() can
pass in a NULL prev task in the unlikely case of hot-un-plug, provide
a fake task such that we can remove all the NULL checks from the far
more common paths.
A further problem; not previously spotted; is that because we pushed
pre_schedule() and idle_balance() into pick_next_task() we now need to
avoid those getting called and pulling more tasks on our dying CPU.
We avoid pull_{dl,rt}_task() by setting fake_task.prio to MAX_PRIO+1.
We also note that since we call pick_next_task() exactly the amount of
times we have runnable tasks present, we should never land in
idle_balance().
Fixes: 38033c37fa ("sched: Push down pre_schedule() and idle_balance()")
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Kirill Tkhai <tkhai@yandex.ru>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140212094930.GB3545@laptop.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Remove idle_balance() from the public life; also reduce some #ifdef
clutter by folding the pick_next_task_fair() idle path into
idle_balance().
Cc: mingo@kernel.org
Reported-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140211151148.GP27965@twins.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Sasha reported:
[ 522.645288] BUG: unable to handle kernel NULL pointer dereference at ...
[ 522.646271] IP: [<ffffffff81186c6f>] check_preempt_wakeup+0x11f/0x210
...
[ 522.650021] Call Trace:
[ 522.650021] <IRQ>
[ 522.650021] [<ffffffff8117361d>] check_preempt_curr+0x3d/0xb0
[ 522.650021] [<ffffffff81175d88>] ttwu_do_wakeup+0x18/0x130
...
which was caused by the se-depth changed during the time when task is not
FAIR, and we will use the wrong depth value after it switched back to FAIR.
This patch reset the depth at the time when task switched to FAIR, make sure
that we always have the correct value when task is FAIR.
Cc: Ingo Molnar <mingo@kernel.org>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5305732D.70001@linux.vnet.ibm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
In deadline class we do not have group scheduling like in RT.
dl_nr_total is the same as dl_nr_running. So, one of them should
be removed.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/368631392675853@web20h.yandex.ru
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
A hot-removed CPU may have ID that is numerically larger than the number of
existing CPUs in the system (e.g. we can unplug CPU 4 from a system that
has CPUs 0, 1 and 4).
Thus the WARN_ONs should check whether the CPU in question is currently
present, not whether its ID value is less than num_present_cpus().
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392646353-1874-1-git-send-email-boris.ostrovsky@oracle.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Because of a recent syscall design debate; its deemed appropriate for
each syscall to have a flags argument for future extension; without
immediately requiring new syscalls.
Cc: juri.lelli@gmail.com
Cc: Ingo Molnar <mingo@redhat.com>
Suggested-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140214161929.GL27965@twins.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We're copying the on-stack structure to userspace, but forgot to give
the right number of bytes to copy. This allows the calling process to
obtain up to PAGE_SIZE bytes from the stack (and possibly adjacent
kernel memory).
This fix copies only as much as we actually have on the stack
(attr->size defaults to the size of the struct) and leaves the rest of
the userspace-provided buffer untouched.
Found using kmemcheck + trinity.
Fixes: d50dde5a10 ("sched: Add new scheduler syscalls to support an extended scheduling parameters ABI")
Cc: Dario Faggioli <raistlin@linux.it>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392585857-10725-1-git-send-email-vegard.nossum@oracle.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Normally task_numa_work scans over a fairly small amount of memory,
but it is possible to run into a large unpopulated part of virtual
memory, with no pages mapped. In that case, task_numa_work can run
for a while, and it may make sense to reschedule as required.
Cc: akpm@linux-foundation.org
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Reported-by: Xing Gang <gang.xing@hp.com>
Tested-by: Chegu Vinod <chegu_vinod@hp.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392761566-24834-2-git-send-email-riel@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Fix this lockdep warning:
[ 44.804600] =========================================================
[ 44.805746] [ INFO: possible irq lock inversion dependency detected ]
[ 44.805746] 3.14.0-rc2-test+ #14 Not tainted
[ 44.805746] ---------------------------------------------------------
[ 44.805746] bash/3674 just changed the state of lock:
[ 44.805746] (&dl_b->lock){+.....}, at: [<ffffffff8106ad15>] sched_rt_handler+0x132/0x248
[ 44.805746] but this lock was taken by another, HARDIRQ-safe lock in the past:
[ 44.805746] (&rq->lock){-.-.-.}
and interrupts could create inverse lock ordering between them.
[ 44.805746]
[ 44.805746] other info that might help us debug this:
[ 44.805746] Possible interrupt unsafe locking scenario:
[ 44.805746]
[ 44.805746] CPU0 CPU1
[ 44.805746] ---- ----
[ 44.805746] lock(&dl_b->lock);
[ 44.805746] local_irq_disable();
[ 44.805746] lock(&rq->lock);
[ 44.805746] lock(&dl_b->lock);
[ 44.805746] <Interrupt>
[ 44.805746] lock(&rq->lock);
by making dl_b->lock acquiring always IRQ safe.
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392107067-19907-3-git-send-email-juri.lelli@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Don't compare sysctl_sched_rt_runtime against sysctl_sched_rt_period if
the former is equal to RUNTIME_INF, otherwise disabling -rt bandwidth
management (with CONFIG_RT_GROUP_SCHED=n) fails.
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392107067-19907-2-git-send-email-juri.lelli@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
While debugging the crash with the bad nr_running accounting, I hit
another bug where, after running my sched deadline test, I was getting
failures to take a CPU offline. It was giving me a -EBUSY error.
Adding a bunch of trace_printk()s around, I found that the cpu
notifier that called sched_cpu_inactive() was returning a failure. The
overflow value was coming up negative?
Talking this over with Juri, the problem is that the total_bw update was
suppose to be made by dl_overflow() which, during my tests, seemed to
not be called. Adding more trace_printk()s, it wasn't that it wasn't
called, but it exited out right away with the check of new_bw being
equal to p->dl.dl_bw. The new_bw calculates the ratio between period and
runtime. The bug is that if you set a deadline, you do not need to set
a period if you plan on the period being equal to the deadline. That
is, if period is zero and deadline is not, then the system call should
set the period to be equal to the deadline. This is done elsewhere in
the code.
The fix is easy, check if period is set, and if it is not, then use the
deadline.
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140219135335.7e74abd4@gandalf.local.home
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Rostedt writes:
My test suite was locking up hard when enabling mmiotracer. This was due
to the mmiotracer placing all but one CPU offline. I found this out
when I was able to reproduce the bug with just my stress-cpu-hotplug
test. This bug baffled me because it would not always trigger, and
would only trigger on the first run after boot up. The
stress-cpu-hotplug test would crash hard the first run, or never crash
at all. But a new reboot may cause it to crash on the first run again.
I spent all week bisecting this, as I couldn't find a consistent
reproducer. I finally narrowed it down to the sched deadline patches,
and even more peculiar, to the commit that added the sched
deadline boot up self test to the latency tracer. Then it dawned on me
to what the bug was.
All it took was to run a task under sched deadline to screw up the CPU
hot plugging. This explained why it would lock up only on the first run
of the stress-cpu-hotplug test. The bug happened when the boot up self
test of the schedule latency tracer would test a deadline task. The
deadline task would corrupt something that would cause CPU hotplug to
fail. If it didn't corrupt it, the stress test would always work
(there's no other sched deadline tasks that would run to cause
problems). If it did corrupt on boot up, the first test would lockup
hard.
I proved this theory by running my deadline test program on another box,
and then run the stress-cpu-hotplug test, and it would now consistently
lock up. I could run stress-cpu-hotplug over and over with no problem,
but once I ran the deadline test, the next run of the
stress-cpu-hotplug would lock hard.
After adding lots of tracing to the code, I found the cause. The
function tracer showed that migrate_tasks() was stuck in an infinite
loop, where rq->nr_running never equaled 1 to break out of it. When I
added a trace_printk() to see what that number was, it was 335 and
never decrementing!
Looking at the deadline code I found:
static void __dequeue_task_dl(struct rq *rq, struct task_struct *p, int flags) {
dequeue_dl_entity(&p->dl);
dequeue_pushable_dl_task(rq, p);
}
static void dequeue_task_dl(struct rq *rq, struct task_struct *p, int flags) {
update_curr_dl(rq);
__dequeue_task_dl(rq, p, flags);
dec_nr_running(rq);
}
And this:
if (dl_runtime_exceeded(rq, dl_se)) {
__dequeue_task_dl(rq, curr, 0);
if (likely(start_dl_timer(dl_se, curr->dl.dl_boosted)))
dl_se->dl_throttled = 1;
else
enqueue_task_dl(rq, curr, ENQUEUE_REPLENISH);
if (!is_leftmost(curr, &rq->dl))
resched_task(curr);
}
Notice how we call __dequeue_task_dl() and in the else case we
call enqueue_task_dl()? Also notice that dequeue_task_dl() has
underscores where enqueue_task_dl() does not. The enqueue_task_dl()
calls inc_nr_running(rq), but __dequeue_task_dl() does not. This is
where we get nr_running out of sync.
[snip]
Another point where nr_running can get out of sync is when the dl_timer
fires:
dl_se->dl_throttled = 0;
if (p->on_rq) {
enqueue_task_dl(rq, p, ENQUEUE_REPLENISH);
if (task_has_dl_policy(rq->curr))
check_preempt_curr_dl(rq, p, 0);
else
resched_task(rq->curr);
This patch does two things:
- correctly accounts for throttled tasks (that are now considered
!running);
- fixes the bug, updating nr_running from {inc,dec}_dl_tasks(),
since we risk to update it twice in some situations (e.g., a
task is dequeued while it has exceeded its budget).
Cc: mingo@redhat.com
Cc: torvalds@linux-foundation.org
Cc: akpm@linux-foundation.org
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392884379-13744-1-git-send-email-juri.lelli@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The finish_arch_post_lock_switch is called at the end of the task
switch after all locks have been released. In concept it is paired
with the switch_mm function, but the current code only does the
call in finish_task_switch. Add the call to idle_task_exit and
use_mm. One use case for the additional calls is s390 which will
use finish_arch_post_lock_switch to wait for the completion of
TLB flush operations.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull cgroup fixes from Tejun Heo:
"Quite a few fixes this time.
Three locking fixes, all marked for -stable. A couple error path
fixes and some misc fixes. Hugh found a bug in memcg offlining
sequence and we thought we could fix that from cgroup core side but
that turned out to be insufficient and got reverted. A different fix
has been applied to -mm"
* 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: update cgroup_enable_task_cg_lists() to grab siglock
Revert "cgroup: use an ordered workqueue for cgroup destruction"
cgroup: protect modifications to cgroup_idr with cgroup_mutex
cgroup: fix locking in cgroup_cfts_commit()
cgroup: fix error return from cgroup_create()
cgroup: fix error return value in cgroup_mount()
cgroup: use an ordered workqueue for cgroup destruction
nfs: include xattr.h from fs/nfs/nfs3proc.c
cpuset: update MAINTAINERS entry
arm, pm, vmpressure: add missing slab.h includes
Pull workqueue fixes from Tejun Heo:
"Two workqueue fixes. One for an unlikely but possible critical bug
during kworker shutdown and the other to make lockdep names a bit more
descriptive"
* 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: ensure @task is valid across kthread_stop()
workqueue: add args to workqueue lockdep name
The ENABLED flag needs to be cleared when a ftrace_ops is unregistered
otherwise it wont be able to be registered again.
This is only for static tracing and does not affect DYNAMIC_FTRACE at
all.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Being able to change the trace clock at boot can be advantageous if
you need a better source of when things happen across CPUs. The default
trace clock is the fastest, but it uses local clocks which may not be
synced across CPUs and it does not let you know when events took place
with respect to events on other CPUs.
The global trace clock can help in this case, and if you do not care
about timings, the counter "clock" is the best, as that is just a simple
atomic counter that is incremented for every event.
Usage is to add "trace_clock=counter" on the kernel command line. You
can replace counter with "global" or any of the clocks listed in
/sys/kernel/debug/tracing/trace_clock
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Appreciated-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
It seems there's no reason to prevent mixed used of ftrace and perf
for a single uprobe event. At least the kprobes already support it.
Link: http://lkml.kernel.org/r/1389946120-19610-6-git-send-email-namhyung@kernel.org
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add support for event triggering to uprobes. This is same as kprobes
support added by Tom (plus cleanup by Steven).
Link: http://lkml.kernel.org/r/1389946120-19610-5-git-send-email-namhyung@kernel.org
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Support multi-buffer on uprobe-based dynamic events by
using ftrace_event_file.
This patch is based kprobe-based dynamic events multibuffer
support work initially, commited by Masami(commit 41a7dd420c),
but revised as below:
Oleg changed the kprobe-based multibuffer design from
array-pointers of ftrace_event_file into simple list,
so this patch also change to the list design.
rcu_read_lock/unlock added into uprobe_trace_func/uretprobe_trace_func,
to synchronize with ftrace_event_file list add and delete.
Even though we allow multi-uprobes instances now,
but TP_FLAG_PROFILE/TP_FLAG_TRACE are still mutually exclusive
in probe_event_enable currently, this means we cannot allow
one user is using uprobe-tracer, and another user is using
perf-probe on same uprobe concurrently.
(Perhaps this will be fix in future, kprobe don't have this
limitation now)
Link: http://lkml.kernel.org/r/1389946120-19610-4-git-send-email-namhyung@kernel.org
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
A single uprobe event might serve different users like ftrace and
perf. And this is especially important for upcoming multi buffer
support. But in this case it'll fetch (same) data from userspace
multiple times. So move it to the beginning of the dispatcher
function and reuse it for each users.
Link: http://lkml.kernel.org/r/1389946120-19610-3-git-send-email-namhyung@kernel.org
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The uprobe_{trace,perf}_print functions are misnomers since what they
do is not printing. There's also a real print function named
print_uprobe_event() so they'll only increase confusion IMHO.
Rename them with double underscores to follow convention of kprobe.
Link: http://lkml.kernel.org/r/1389946120-19610-2-git-send-email-namhyung@kernel.org
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Create a "set_ftrace_filter" and "set_ftrace_notrace" files in the instance
directories to let users filter of functions to trace for the given instance.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In preparation for having the function tracing instances be able to
filter on functions, the generic filter functions must first be
converted to take in the global_ops as a parameter.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Allow instances (sub-buffers) to enable function tracing.
Each instance will have its own function tracing capability.
For now, instances will not have function stack tracing, or will
they be able to pick and choose what functions they can trace.
Picking and choosing their own functions will come later.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As tracers will soon be used by instances, the tracer enabled field
needs to be converted to a counter instead of a boolean.
This counter is protected by the trace_types_lock mutex.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When an instance is about to be deleted, make sure the tracer
is set to nop. If it isn't reset the tracer and set it to the nop
tracer, otherwise memory leaks and bad pointers may result.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If global_ops function is being called directly, instead of the global_ops
list function, set the global_ops private to be the same as the ops private
that's being called directly.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
