Peter Zijlstra [Thu, 19 Jan 2017 17:44:08 +0000 (18:44 +0100)]
sched/core: Optimize pick_next_task() for idle_sched_class
Steve noticed that when we switch from IDLE to SCHED_OTHER we fail to
take the shortcut, even though all runnable tasks are of the fair
class, because prev->sched_class != &fair_sched_class.
Since I reworked the put_prev_task() stuff, we don't really care about
prev->class here, so removing that condition will allow this case.
This increases the likely case from 78% to 98% correct for Steve's
workload.
Reported-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Tested-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170119174408.GN6485@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Peter Zijlstra [Thu, 19 Jan 2017 13:36:33 +0000 (14:36 +0100)]
sched/clock: Fix hotplug crash
Mike reported that he could trigger the WARN_ON_ONCE() in
set_sched_clock_stable() using hotplug.
This exposed a fundamental problem with the interface, we should never
mark the TSC stable if we ever find it to be unstable. Therefore
set_sched_clock_stable() is a broken interface.
The reason it existed is that not having it is a pain, it means all
relevant architecture code needs to call clear_sched_clock_stable()
where appropriate.
Of the three architectures that select HAVE_UNSTABLE_SCHED_CLOCK ia64
and parisc are trivial in that they never called
set_sched_clock_stable(), so add an unconditional call to
clear_sched_clock_stable() to them.
For x86 the story is a lot more involved, and what this patch tries to
do is ensure we preserve the status quo. So even is Cyrix or Transmeta
have usable TSC they never called set_sched_clock_stable() so they now
get an explicit mark unstable.
Reported-by: Mike Galbraith <efault@gmx.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 9881b024b7d7 ("sched/clock: Delay switching sched_clock to stable") Link: http://lkml.kernel.org/r/20170119133633.GB6536@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tejun Heo [Fri, 28 Oct 2016 16:58:12 +0000 (12:58 -0400)]
fs/jbd2, locking/mutex, sched/wait: Use mutex_lock_io() for journal->j_checkpoint_mutex
When an ext4 fs is bogged down by a lot of metadata IOs (in the
reported case, it was deletion of millions of files, but any massive
amount of journal writes would do), after the journal is filled up,
tasks which try to access the filesystem and aren't currently
performing the journal writes end up waiting in
__jbd2_log_wait_for_space() for journal->j_checkpoint_mutex.
Because those mutex sleeps aren't marked as iowait, this condition can
lead to misleadingly low iowait and /proc/stat:procs_blocked. While
iowait propagation is far from strict, this condition can be triggered
fairly easily and annotating these sleeps correctly helps initial
diagnosis quite a bit.
Use the new mutex_lock_io() for journal->j_checkpoint_mutex so that
these sleeps are properly marked as iowait.
Reported-by: Mingbo Wan <mingbo@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jan Kara <jack@suse.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kernel-team@fb.com Link: http://lkml.kernel.org/r/1477673892-28940-5-git-send-email-tj@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tejun Heo [Fri, 28 Oct 2016 16:58:11 +0000 (12:58 -0400)]
locking/mutex, sched/wait: Add mutex_lock_io()
We sometimes end up propagating IO blocking through mutexes; however,
because there currently is no way of annotating mutex sleeps as
iowait, there are cases where iowait and /proc/stat:procs_blocked
report misleading numbers obscuring the actual state of the system.
This patch adds mutex_lock_io() so that mutex sleeps can be marked as
iowait in those cases.
Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: adilger.kernel@dilger.ca Cc: jack@suse.com Cc: kernel-team@fb.com Cc: mingbo@fb.com Cc: tytso@mit.edu Link: http://lkml.kernel.org/r/1477673892-28940-4-git-send-email-tj@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tejun Heo [Fri, 28 Oct 2016 16:58:10 +0000 (12:58 -0400)]
sched/core: Separate out io_schedule_prepare() and io_schedule_finish()
Now that IO schedule accounting is done inside __schedule(),
io_schedule() can be split into three steps - prep, schedule, and
finish - where the schedule part doesn't need any special annotation.
This allows marking a sleep as iowait by simply wrapping an existing
blocking function with io_schedule_prepare() and io_schedule_finish().
Because task_struct->in_iowait is single bit, the caller of
io_schedule_prepare() needs to record and the pass its state to
io_schedule_finish() to be safe regarding nesting. While this isn't
the prettiest, these functions are mostly gonna be used by core
functions and we don't want to use more space for ->in_iowait.
While at it, as it's simple to do now, reimplement io_schedule()
without unnecessarily going through io_schedule_timeout().
Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: adilger.kernel@dilger.ca Cc: jack@suse.com Cc: kernel-team@fb.com Cc: mingbo@fb.com Cc: tytso@mit.edu Link: http://lkml.kernel.org/r/1477673892-28940-3-git-send-email-tj@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tejun Heo [Wed, 7 Dec 2016 20:48:41 +0000 (15:48 -0500)]
sched/core: move IO scheduling accounting from io_schedule_timeout() into scheduler
For an interface to support blocking for IOs, it must call
io_schedule() instead of schedule(). This makes it tedious to add IO
blocking to existing interfaces as the switching between schedule()
and io_schedule() is often buried deep.
As we already have a way to mark the task as IO scheduling, this can
be made easier by separating out io_schedule() into multiple steps so
that IO schedule preparation can be performed before invoking a
blocking interface and the actual accounting happens inside the
scheduler.
io_schedule_timeout() does the following three things prior to calling
schedule_timeout().
1. Mark the task as scheduling for IO.
2. Flush out plugged IOs.
3. Account the IO scheduling.
done close to the actual scheduling. This patch moves #3 into the
scheduler so that later patches can separate out preparation and
finish steps from io_schedule().
Patch-originally-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: adilger.kernel@dilger.ca Cc: akpm@linux-foundation.org Cc: axboe@kernel.dk Cc: jack@suse.com Cc: kernel-team@fb.com Cc: mingbo@fb.com Cc: tytso@mit.edu Link: http://lkml.kernel.org/r/20161207204841.GA22296@htj.duckdns.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vincent Guittot [Wed, 21 Dec 2016 15:50:26 +0000 (16:50 +0100)]
sched/core: Fix group_entity's share update
The update of the share of a cfs_rq is done when its load_avg is updated
but before the group_entity's load_avg has been updated for the past time
slot. This generates wrong load_avg accounting which can be significant
when small tasks are involved in the scheduling.
Let take the example of a task a that is dequeued of its task group A:
root
(cfs_rq)
\
(se)
A
(cfs_rq)
\
(se)
a
Task "a" was the only task in task group A which becomes idle when a is
dequeued.
We have the sequence:
- dequeue_entity a->se
- update_load_avg(a->se)
- dequeue_entity_load_avg(A->cfs_rq, a->se)
- update_cfs_shares(A->cfs_rq)
A->cfs_rq->load.weight == 0
A->se->load.weight is updated with the new share (0 in this case)
- dequeue_entity A->se
- update_load_avg(A->se) but its weight is now null so the last time
slot (up to a tick) will be accounted with a weight of 0 instead of
its real weight during the time slot. The last time slot will be
accounted as an idle one whereas it was a running one.
If the running time of task a is short enough that no tick happens when it
runs, all running time of group entity A->se will be accounted as idle
time.
Instead, we should update the share of a cfs_rq (in fact the weight of its
group entity) only after having updated the load_avg of the group_entity.
update_cfs_shares() now takes the sched_entity as a parameter instead of the
cfs_rq, and the weight of the group_entity is updated only once its load_avg
has been synced with current time.
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: pjt@google.com Link: http://lkml.kernel.org/r/1482335426-7664-1-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Peter Zijlstra [Wed, 21 Dec 2016 08:05:02 +0000 (09:05 +0100)]
sched/completions: Fix complete_all() semantics
Documentation/scheduler/completion.txt says this about complete_all():
"calls complete_all() to signal all current and future waiters."
Which doesn't strictly match the current semantics. Currently
complete_all() is equivalent to UINT_MAX/2 complete() invocations,
which is distinctly less than 'all current and future waiters'
(enumerable vs innumerable), although it has worked in practice.
However, Dmitry had a weird case where it might matter, so change
completions to use saturation semantics for complete()/complete_all().
Once done hits UINT_MAX (and complete_all() sets it there) it will
never again be decremented.
Requested-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: der.herr@hofr.at Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/deadline: Show leftover runtime and abs deadline in /proc/*/sched
This patch allows for reading the current (leftover) runtime and
absolute deadline of a SCHED_DEADLINE task through /proc/*/sched
(entries dl.runtime and dl.deadline), while debugging/testing.
Signed-off-by: Tommaso Cucinotta <tommaso.cucinotta@sssup.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@arm.com> Reviewed-by: Luca Abeni <luca.abeni@unitn.it> Acked-by: Daniel Bistrot de Oliveira <danielbristot@gmail.com> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1477473437-10346-2-git-send-email-tommaso.cucinotta@sssup.it Signed-off-by: Ingo Molnar <mingo@kernel.org>
Peter Zijlstra [Thu, 15 Dec 2016 12:36:17 +0000 (13:36 +0100)]
sched/clock: Provide better clock continuity
When switching between the unstable and stable variants it is
currently possible that clock discontinuities occur.
And while these will mostly be 'small', attempt to do better.
As observed on my IVB-EP, the sched_clock() is ~1.5s ahead of the
ktime_get_ns() based timeline at the point of switchover
(sched_clock_init_late()) after SMP bringup.
Equally, when the TSC is later found to be unstable -- typically
because SMM tries to hide its SMI latencies by mucking with the TSC --
we want to avoid large jumps.
Since the clocksource watchdog reports the issue after the fact we
cannot exactly fix up time, but since SMI latencies are typically
small (~10ns range), the discontinuity is mainly due to drift between
sched_clock() and ktime_get_ns() (which on my desktop is ~79s over
24days).
I dislike this patch because it adds overhead to the good case in
favour of dealing with badness. But given the widespread failure of
TSC stability this is worth it.
Note that in case the TSC makes drastic jumps after SMP bringup we're
still hosed. There's just not much we can do in that case without
stupid overhead.
If we were to somehow expose tsc_clocksource_reliable (which is hard
because this code is also used on ia64 and parisc) we could avoid some
of the newly introduced overhead.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Peter Zijlstra [Thu, 15 Dec 2016 12:35:52 +0000 (13:35 +0100)]
sched/clock: Delay switching sched_clock to stable
Currently we switch to the stable sched_clock if we guess the TSC is
usable, and then switch back to the unstable path if it turns out TSC
isn't stable during SMP bringup after all.
Delay switching to the stable path until after SMP bringup is
complete. This way we'll avoid switching during the time we detect the
worst of the TSC offences.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Matt Fleming [Wed, 21 Sep 2016 13:38:13 +0000 (14:38 +0100)]
sched/core: Add debugging code to catch missing update_rq_clock() calls
There's no diagnostic checks for figuring out when we've accidentally
missed update_rq_clock() calls. Let's add some by piggybacking on the
rq_*pin_lock() wrappers.
The idea behind the diagnostic checks is that upon pining rq lock the
rq clock should be updated, via update_rq_clock(), before anybody
reads the clock with rq_clock() or rq_clock_task().
The exception to this rule is when updates have explicitly been
disabled with the rq_clock_skip_update() optimisation.
There are some functions that only unpin the rq lock in order to grab
some other lock and avoid deadlock. In that case we don't need to
update the clock again and the previous diagnostic state can be
carried over in rq_repin_lock() by saving the state in the rq_flags
context.
Since this patch adds a new clock update flag and some already exist
in rq::clock_skip_update, that field has now been renamed. An attempt
has been made to keep the flag manipulation code small and fast since
it's used in the heart of the __schedule() fast path.
For the !CONFIG_SCHED_DEBUG case the only object code change (other
than addresses) is the following change to reset RQCF_ACT_SKIP inside
of __schedule(),
Peter Zijlstra [Mon, 3 Oct 2016 14:35:32 +0000 (16:35 +0200)]
sched/core: Add missing update_rq_clock() call for task_hot()
Add the update_rq_clock() call at the top of the callstack instead of
at the bottom where we find it missing, this to aid later effort to
minimize the number of update_rq_lock() calls.
Peter Zijlstra [Mon, 3 Oct 2016 14:28:37 +0000 (16:28 +0200)]
sched/core: Add missing update_rq_clock() in detach_task_cfs_rq()
Instead of adding the update_rq_clock() all the way at the bottom of
the callstack, add one at the top, this to aid later effort to
minimize update_rq_lock() calls.
Matt Fleming [Wed, 21 Sep 2016 13:38:11 +0000 (14:38 +0100)]
sched/core: Reset RQCF_ACT_SKIP before unpinning rq->lock
rq_clock() is called from sched_info_{depart,arrive}() after resetting
RQCF_ACT_SKIP but prior to a call to update_rq_clock().
In preparation for pending patches that check whether the rq clock has
been updated inside of a pin context before rq_clock() is called, move
the reset of rq->clock_skip_update immediately before unpinning the rq
lock.
This will avoid the new warnings which check if update_rq_clock() is
being actively skipped.
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@unitn.it> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Galbraith <efault@gmx.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Rik van Riel <riel@redhat.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yuyang Du <yuyang.du@intel.com> Link: http://lkml.kernel.org/r/20160921133813.31976-6-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
Matt Fleming [Wed, 21 Sep 2016 13:38:10 +0000 (14:38 +0100)]
sched/core: Add wrappers for lockdep_(un)pin_lock()
In preparation for adding diagnostic checks to catch missing calls to
update_rq_clock(), provide wrappers for (re)pinning and unpinning
rq->lock.
Because the pending diagnostic checks allow state to be maintained in
rq_flags across pin contexts, swap the 'struct pin_cookie' arguments
for 'struct rq_flags *'.
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luca Abeni <luca.abeni@unitn.it> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Galbraith <efault@gmx.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Rik van Riel <riel@redhat.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Cc: Yuyang Du <yuyang.du@intel.com> Link: http://lkml.kernel.org/r/20160921133813.31976-5-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/cputime: Rename vtime_account_user() to vtime_flush()
CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y used to accumulate user time and
account it on ticks and context switches only through the
vtime_account_user() function.
Now this model has been generalized on the 3 archs for all kind of
cputime (system, irq, ...) and all the cputime flushing happens under
vtime_account_user().
So let's rename this function to better reflect its new role.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1483636310-6557-11-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/cputime, s390: Implement delayed accounting of system time
The account_system_time() function is called with a cputime that
occurred while running in the kernel. The function detects which
context the CPU is currently running in and accounts the time to
the correct bucket. This forces the arch code to account the
cputime for hardirq and softirq immediately.
Such accounting function can be costly and perform unwelcome divisions
and multiplications, among others.
The arch code can delay the accounting for system time. For s390
the accounting is done once per timer tick and for each task switch.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
[ Rebase against latest linus tree and move account_system_index_scaled(). ] Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1483636310-6557-10-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/cputime, ia64: Accumulate cputime and account only on tick/task switch
Currently CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y accounts the cputime on
any context boundary: irq entry/exit, guest entry/exit, context switch,
etc...
Calling functions such as account_system_time(), account_user_time()
and such can be costly, especially if they are called on many fastpath
such as twice per IRQ. Those functions do more than just accounting to
kcpustat and task cputime. Depending on the config, some subsystems can
perform unpleasant multiplications and divisions, among other things.
So lets accumulate the cputime instead and delay the accounting on ticks
and context switches only.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1483636310-6557-9-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/cputime, powerpc/vtime: Accumulate cputime and account only on tick/task switch
Currently CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y accounts the cputime on
any context boundary: irq entry/exit, guest entry/exit, context switch,
etc...
Calling functions such as account_system_time(), account_user_time()
and such can be costly, especially if they are called on many fastpath
such as twice per IRQ. Those functions do more than just accounting to
kcpustat and task cputime. Depending on the config, some subsystems can
perform unpleasant multiplications and divisions, among other things.
So lets accumulate the cputime instead and delay the accounting on ticks
and context switches only.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1483636310-6557-8-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/cputime, powerpc: Prepare accounting structure for cputime flush on tick
In order to prepare for CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y to delay
cputime accounting to the tick, provide finegrained accumulators to
powerpc in order to store the cputime until flushing.
While at it, normalize the name of several fields according to common
cputime naming.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1483636310-6557-6-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
In order to prepare for CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y to delay
cputime accounting to the tick, let's allow archs to account cputime
directly to gtime.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1483636310-6557-5-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/cputime: Allow accounting system time using cpustat index
In order to prepare for CONFIG_VIRT_CPU_ACCOUNTING_NATIVE=y to delay
cputime accounting to the tick, let's provide APIs to account system
time to precise contexts: hardirq, softirq, pure system, ...
Inspired-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1483636310-6557-4-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/cputime, powerpc32: Fix stale scaled stime on context switch
On context switch with powerpc32, the cputime is accumulated in the
thread_info struct. So the switching-in task must move forward its
start time snapshot to the current time in order to later compute the
delta spent in system mode.
This is what we do for the normal cputime by initializing the starttime
field to the value of the previous task's starttime which got freshly
updated.
But we are missing the update of the scaled cputime start time. As a
result we may be accounting too much scaled cputime later.
Fix this by initializing the scaled cputime the same way we do for
normal cputime.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Wanpeng Li <wanpeng.li@hotmail.com> Link: http://lkml.kernel.org/r/1483636310-6557-2-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Linus Torvalds [Sat, 14 Jan 2017 01:40:22 +0000 (17:40 -0800)]
Merge branch 'for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"These are all over the place.
The tracepoint part of the pull fixes a crash and adds a little more
information to two tracepoints, while the rest are good old fashioned
fixes"
* 'for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: make tracepoint format strings more compact
Btrfs: add truncated_len for ordered extent tracepoints
Btrfs: add 'inode' for extent map tracepoint
btrfs: fix crash when tracepoint arguments are freed by wq callbacks
Btrfs: adjust outstanding_extents counter properly when dio write is split
Btrfs: fix lockdep warning about log_mutex
Btrfs: use down_read_nested to make lockdep silent
btrfs: fix locking when we put back a delayed ref that's too new
btrfs: fix error handling when run_delayed_extent_op fails
btrfs: return the actual error value from from btrfs_uuid_tree_iterate
Linus Torvalds [Sat, 14 Jan 2017 01:35:43 +0000 (17:35 -0800)]
Merge tag 'vfio-v4.10-rc4' of git://github.com/awilliam/linux-vfio
Pull VFIO fixes from Alex Williamson:
- Cleanups and bug fixes for the mtty sample driver (Dan Carpenter)
- Export and make use of has_capability() to fix incorrect use of
ns_capable() for testing task capabilities (Jike Song)
* tag 'vfio-v4.10-rc4' of git://github.com/awilliam/linux-vfio:
vfio/type1: Remove pid_namespace.h include
vfio iommu type1: fix the testing of capability for remote task
capability: export has_capability
vfio-mdev: remove some dead code
vfio-mdev: buffer overflow in ioctl()
vfio-mdev: return -EFAULT if copy_to_user() fails
Linus Torvalds [Sat, 14 Jan 2017 01:00:42 +0000 (17:00 -0800)]
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Catalin Marinas:
- Fix huge_ptep_set_access_flags() to return "changed" when any of the
ptes in the contiguous range is changed, not just the last one
- Fix the adr_l assembly macro to work in modules under KASLR
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: assembler: make adr_l work in modules under KASLR
arm64: hugetlb: fix the wrong return value for huge_ptep_set_access_flags
Linus Torvalds [Fri, 13 Jan 2017 20:38:36 +0000 (12:38 -0800)]
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"The major fix is the bfa firmware, since the latest 10Gb cards fail
probing with the current firmware.
The rest is a set of minor fixes: one missed Kconfig dependency
causing randconfig failures, a missed error return on an error leg, a
change for how multiqueue waits on a blocked device and a don't reset
while in reset fix"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: bfa: Increase requested firmware version to 3.2.5.1
scsi: snic: Return error code on memory allocation failure
scsi: fnic: Avoid sending reset to firmware when another reset is in progress
scsi: qedi: fix build, depends on UIO
scsi: scsi-mq: Wait for .queue_rq() if necessary
Linus Torvalds [Fri, 13 Jan 2017 19:49:34 +0000 (11:49 -0800)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input updates from Dmitry Torokhov:
"Small driver fixups"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: elants_i2c - avoid divide by 0 errors on bad touchscreen data
Input: adxl34x - make it enumerable in ACPI environment
Input: ALPS - fix TrackStick Y axis handling for SS5 hardware
Input: synaptics-rmi4 - fix F03 build error when serio is module
Input: xpad - use correct product id for x360w controllers
Input: synaptics_i2c - change msleep to usleep_range for small msecs
Input: i8042 - add Pegatron touchpad to noloop table
Input: joydev - remove unused linux/miscdevice.h include
Jike Song [Thu, 12 Jan 2017 08:52:03 +0000 (16:52 +0800)]
vfio iommu type1: fix the testing of capability for remote task
Before the mdev enhancement type1 iommu used capable() to test the
capability of current task; in the course of mdev development a
new requirement, testing for another task other than current, was
raised. ns_capable() was used for this purpose, however it still
tests current, the only difference is, in a specified namespace.
Fix it by using has_capability() instead, which tests the cap for
specified task in init_user_ns, the same namespace as capable().
Cc: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Jike Song <jike.song@intel.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Linus Torvalds [Thu, 12 Jan 2017 22:45:59 +0000 (14:45 -0800)]
Merge tag 'sound-4.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"This time we got a few more fixes than the previous rc's, and most of
commits were about ASoC.
The only significant change in the core side is the regression fix wrt
the aux device list handling, and all the rest are driver-specific
small / trivial fixes"
* tag 'sound-4.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: usb-audio: Add a quirk for Plantronics BT600
ASoC: rt5645: set sel_i2s_pre_div1 to 2
ASoC: dpcm: Avoid putting stream state to STOP when FE stream is paused
ASoC: Intel: Skylake: Release FW ctx in cleanup
ASoC: Intel: bytcr-rt5640: fix settings in internal clock mode
ASoC: fsl_ssi: set fifo watermark to more reliable value
ASoC: nau8825: fix invalid configuration in Pre-Scalar of FLL
ASoC: nau8825: correct the function name of register
ASoC: Intel: Skylake: Fix to fail safely if module not available in path
ASoC: tlv320aic3x: Mark the RESET register as volatile
ASoC: Fix binding and probing of auxiliary components
ASoC: wm_adsp: Don't overrun firmware file buffer when reading region data
ASoC: Intel: bytcr_rt5640: fallback mechanism if MCLK is not enabled
ASoC: hdmi-codec: use unsigned type to structure members with bit-field
ASoC: topology: kfree kcontrol->private_value before freeing kcontrol
ASoC: rsnd: don't double free kctrl
ASoC: dwc: Fix PIO mode initialization
Linus Torvalds [Thu, 12 Jan 2017 19:00:22 +0000 (11:00 -0800)]
Merge tag 'rproc-v4.10-fixes' of git://github.com/andersson/remoteproc
Pull remoteproc fixes from Bjorn Andersson:
"This fixes two regressions that have been reported to be introduced in
v4.10-rc1.
- correct an incorrect usage of the kref api
- revert the change to make the resource table read-only. As the
space each vdev resource is used as virtio device config space it
must be shared with the remote"
* tag 'rproc-v4.10-fixes' of git://github.com/andersson/remoteproc:
Revert "remoteproc: Merge table_ptr and cached_table pointers"
remoteproc: fix vdev reference management
Linus Torvalds [Thu, 12 Jan 2017 18:58:16 +0000 (10:58 -0800)]
Merge tag 'rpmsg-v4.10-fixes' of git://github.com/andersson/remoteproc
Pull rpmsg fixes from Bjorn Andersson:
"This fixes a regression introduced in v4.10-rc1 that prohibits
multiple channels with the same name but different endpoint addresses
to be used"
* tag 'rpmsg-v4.10-fixes' of git://github.com/andersson/remoteproc:
rpmsg: virtio_rpmsg_bus: fix channel creation
Linus Torvalds [Thu, 12 Jan 2017 18:55:28 +0000 (10:55 -0800)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
Pull HID fixes from Jiri Kosina:
- device descriptor length validation fix to hid-cypress driver from
Greg
- introduction of a short delay into i2c-hid, which is not really
mandated by the spec, but fixes Asus Touchpads
- Petzl USB connectable flashlight quirk from myself
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
HID: i2c-hid: Add sleep between POWER ON and RESET
HID: hid-cypress: validate length of report
HID: ignore Petzl USB headlamp
Linus Torvalds [Thu, 12 Jan 2017 18:17:59 +0000 (10:17 -0800)]
Merge tag 'md/4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md
Pull md fixes from Shaohua Li:
"Basically one fix for raid5 cache which is merged in this cycle,
others are trival fixes"
* tag 'md/4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
md/raid5: Use correct IS_ERR() variation on pointer check
md: cleanup mddev flag clear for takeover
md/r5cache: fix spelling mistake on "recoverying"
md/r5cache: assign conf->log before r5l_load_log()
md/r5cache: simplify handling of sh->log_start in recovery
md/raid5-cache: removes unnecessary write-through mode judgments
md/raid10: Refactor raid10_make_request
md/raid1: Refactor raid1_make_request
Ard Biesheuvel [Wed, 11 Jan 2017 14:54:53 +0000 (14:54 +0000)]
arm64: assembler: make adr_l work in modules under KASLR
When CONFIG_RANDOMIZE_MODULE_REGION_FULL=y, the offset between loaded
modules and the core kernel may exceed 4 GB, putting symbols exported
by the core kernel out of the reach of the ordinary adrp/add instruction
pairs used to generate relative symbol references. So make the adr_l
macro emit a movz/movk sequence instead when executing in module context.
While at it, remove the pointless special case for the stack pointer.
Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Paolo Bonzini [Thu, 12 Jan 2017 14:02:32 +0000 (15:02 +0100)]
KVM: x86: fix emulation of "MOV SS, null selector"
This is CVE-2017-2583. On Intel this causes a failed vmentry because
SS's type is neither 3 nor 7 (even though the manual says this check is
only done for usable SS, and the dmesg splat says that SS is unusable!).
On AMD it's worse: svm.c is confused and sets CPL to 0 in the vmcb.
The fix fabricates a data segment descriptor when SS is set to a null
selector, so that CPL and SS.DPL are set correctly in the VMCS/vmcb.
Furthermore, only allow setting SS to a NULL selector if SS.RPL < 3;
this in turn ensures CPL < 3 because RPL must be equal to CPL.
Thanks to Andy Lutomirski and Willy Tarreau for help in analyzing
the bug and deciphering the manuals.
The syzkaller folks reported a NULL pointer dereference due to
ENABLE_CAP succeeding even without an irqchip. The Hyper-V
synthetic interrupt controller is activated, resulting in a
wrong request to rescan the ioapic and a NULL pointer dereference.
The syzkaller folks reported a NULL pointer dereference that due to
unregister an consumer which fails registration before. The syzkaller
creates two VMs w/ an equal eventfd occasionally. So the second VM
fails to register an irqbypass consumer. It will make irqfd as inactive
and queue an workqueue work to shutdown irqfd and unregister the irqbypass
consumer when eventfd is closed. However, the second consumer has been
initialized though it fails registration. So the token(same as the first
VM's) is taken to unregister the consumer through the workqueue, the
consumer of the first VM is found and unregistered, then NULL deref incurred
in the path of deleting consumer from the consumers list.
This patch fixes it by making irq_bypass_register/unregister_consumer()
looks for the consumer entry based on consumer pointer itself instead of
token matching.
Reported-by: Dmitry Vyukov <dvyukov@google.com> Suggested-by: Alex Williamson <alex.williamson@redhat.com> Cc: stable@vger.kernel.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Steve Rutherford [Thu, 12 Jan 2017 02:28:29 +0000 (18:28 -0800)]
KVM: x86: Introduce segmented_write_std
Introduces segemented_write_std.
Switches from emulated reads/writes to standard read/writes in fxsave,
fxrstor, sgdt, and sidt. This fixes CVE-2017-2584, a longstanding
kernel memory leak.
Since commit 283c95d0e389 ("KVM: x86: emulate FXSAVE and FXRSTOR",
2016-11-09), which is luckily not yet in any final release, this would
also be an exploitable kernel memory *write*!
Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: stable@vger.kernel.org Fixes: 96051572c819194c37a8367624b285be10297eca Fixes: 283c95d0e3891b64087706b344a4b545d04a6e62 Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Steve Rutherford <srutherford@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
KVM's lapic emulation uses static_key_deferred (apic_{hw,sw}_disabled).
These are implemented with delayed_work structs which can still be
pending when the KVM module is unloaded. We've seen this cause kernel
panics when the kvm_intel module is quickly reloaded.
Use the new static_key_deferred_flush() API to flush pending updates on
module unload.
Signed-off-by: David Matlack <dmatlack@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
David Matlack [Fri, 16 Dec 2016 22:30:35 +0000 (14:30 -0800)]
jump_labels: API for flushing deferred jump label updates
Modules that use static_key_deferred need a way to synchronize with
any delayed work that is still pending when the module is unloaded.
Introduce static_key_deferred_flush() which flushes any pending
jump label updates.
Signed-off-by: David Matlack <dmatlack@google.com> Cc: stable@vger.kernel.org Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Brendan McGrath [Fri, 6 Jan 2017 21:01:38 +0000 (08:01 +1100)]
HID: i2c-hid: Add sleep between POWER ON and RESET
Support for the Asus Touchpad was recently added. It turns out this
device can fail initialisation (and become unusable) when the RESET
command is sent too soon after the POWER ON command.
Unfortunately the i2c-hid specification does not specify the need for
a delay between these two commands. But it was discovered the Windows
driver has a 1ms delay.
As a result, this patch modifies the i2c-hid module to add a sleep
inbetween the POWER ON and RESET commands which lasts between 1ms and 5ms.
See https://github.com/vlasenko/hid-asus-dkms/issues/24 for further
details.
Linus Torvalds [Wed, 11 Jan 2017 19:15:15 +0000 (11:15 -0800)]
Merge branch 'akpm' (patches from Andrew)
Merge fixes from Andrew Morton:
"27 fixes.
There are three patches that aren't actually fixes. They're simple
function renamings which are nice-to-have in mainline as ongoing net
development depends on them."
* akpm: (27 commits)
timerfd: export defines to userspace
mm/hugetlb.c: fix reservation race when freeing surplus pages
mm/slab.c: fix SLAB freelist randomization duplicate entries
zram: support BDI_CAP_STABLE_WRITES
zram: revalidate disk under init_lock
mm: support anonymous stable page
mm: add documentation for page fragment APIs
mm: rename __page_frag functions to __page_frag_cache, drop order from drain
mm: rename __alloc_page_frag to page_frag_alloc and __free_page_frag to page_frag_free
mm, memcg: fix the active list aging for lowmem requests when memcg is enabled
mm: don't dereference struct page fields of invalid pages
mailmap: add codeaurora.org names for nameless email commits
signal: protect SIGNAL_UNKILLABLE from unintentional clearing.
mm: pmd dirty emulation in page fault handler
ipc/sem.c: fix incorrect sem_lock pairing
lib/Kconfig.debug: fix frv build failure
mm: get rid of __GFP_OTHER_NODE
mm: fix remote numa hits statistics
mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done}
ocfs2: fix crash caused by stale lvb with fsdlm plugin
...
Dan Carpenter [Sat, 7 Jan 2017 06:30:08 +0000 (09:30 +0300)]
vfio-mdev: remove some dead code
We set info.count to 1 in mtty_get_irq_info() so static checkers
complain that, "Why do we have impossible conditions?" The answer is
that it seems to be left over dead code that can be safely removed.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Dan Carpenter [Sat, 7 Jan 2017 06:28:40 +0000 (09:28 +0300)]
vfio-mdev: buffer overflow in ioctl()
This is a sample driver for documentation so the impact is probably
pretty low. But we should check that bar_index is valid so we
don't write beyond the end of the mdev_state->region_info[] array.
Fixes: 9d1a546c53b4 ("docs: Sample driver to demonstrate how to use Mediated device framework.") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Dan Carpenter [Sat, 7 Jan 2017 06:27:49 +0000 (09:27 +0300)]
vfio-mdev: return -EFAULT if copy_to_user() fails
The copy_to_user() function returns the number of bytes which it wasn't
able to copy but we want to return a negative error code.
Fixes: 9d1a546c53b4 ("docs: Sample driver to demonstrate how to use Mediated device framework.") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Takashi Iwai [Wed, 11 Jan 2017 18:49:27 +0000 (19:49 +0100)]
Merge tag 'asoc-fix-v4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Fixes for v4.10
As well as the usual smattering of driver specific fixes collected since
the merge window this has one particularly important fix to the core for
handling of aux_devs which was broken during the merge window by some of
the componentization refactoring.
Jan Kara [Wed, 11 Jan 2017 18:20:04 +0000 (10:20 -0800)]
xfs: Timely free truncated dirty pages
Commit 99579ccec4e2 "xfs: skip dirty pages in ->releasepage()" started
to skip dirty pages in xfs_vm_releasepage() which also has the effect
that if a dirty page is truncated, it does not get freed by
block_invalidatepage() and is lingering in LRU list waiting for reclaim.
So a simple loop like:
while true; do
dd if=/dev/zero of=file bs=1M count=100
rm file
done
will keep using more and more memory until we hit low watermarks and
start pagecache reclaim which will eventually reclaim also the truncate
pages. Keeping these truncated (and thus never usable) pages in memory
is just a waste of memory, is unnecessarily stressing page cache
reclaim, and reportedly also leads to anonymous mmap(2) returning ENOMEM
prematurely.
So instead of just skipping dirty pages in xfs_vm_releasepage(), return
to old behavior of skipping them only if they have delalloc or unwritten
buffers and fix the spurious warnings by warning only if the page is
clean.
CC: stable@vger.kernel.org CC: Brian Foster <bfoster@redhat.com> CC: Vlastimil Babka <vbabka@suse.cz> Reported-by: Petr Tůma <petr.tuma@d3s.mff.cuni.cz> Fixes: 99579ccec4e271c3d4d4e7c946058766812afdab Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2) Memory disclosure in appletalk ipddp routing code, from Vlad
Tsyrklevich.
3) r8152 can erroneously split an RX packet into multiple URBs if the
Rx FIFO is not empty when we suspend. Fix this by waiting for the
FIFO to empty before suspending. From Hayes Wang.
4) Two GRO fixes (enter slow path when not enough SKB tail room exists,
disable frag0 optimizations when there are IPV6 extension headers)
from Eric Dumazet and Herbert Xu.
5) A series of mlx5e bug fixes (do source udp port offloading for
tunnels properly, Ip fragment matching fixes, handling firmware
errors properly when installing TC rules, etc.) from Saeed Mahameed,
Or Gerlitz, Roi Dayan, Hadar Hen Zion, Gil Rockah, and Daniel
Jurgens.
6) Two VRF fixes from David Ahern (don't skip multipath selection for
VRF paths, disallow VRF to be configured with table ID 0).
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (35 commits)
net: vrf: do not allow table id 0
net: phy: marvell: fix Marvell 88E1512 used in SGMII mode
sctp: Fix spelling mistake: "Atempt" -> "Attempt"
net: ipv4: Fix multipath selection with vrf
cgroup: move CONFIG_SOCK_CGROUP_DATA to init/Kconfig
gro: use min_t() in skb_gro_reset_offset()
net/mlx5: Only cancel recovery work when cleaning up device
net/mlx5e: Remove WARN_ONCE from adaptive moderation code
net/mlx5e: Un-register uplink representor on nic_disable
net/mlx5e: Properly handle FW errors while adding TC rules
net/mlx5e: Fix kbuild warnings for uninitialized parameters
net/mlx5e: Set inline mode requirements for matching on IP fragments
net/mlx5e: Properly get address type of encapsulation IP headers
net/mlx5e: TC ipv4 tunnel encap offload error flow fixes
net/mlx5e: Warn when rejecting offload attempts of IP tunnels
net/mlx5e: Properly handle offloading of source udp port for IP tunnels
gro: Disable frag0 optimization on IPv6 ext headers
gro: Enter slow-path if there is no tailroom
mlx4: Return EOPNOTSUPP instead of ENOTSUPP
net/af_iucv: don't use paged skbs for TX on HiperSockets
...
David Ahern [Tue, 10 Jan 2017 23:22:25 +0000 (15:22 -0800)]
net: vrf: do not allow table id 0
Frank reported that vrf devices can be created with a table id of 0.
This breaks many of the run time table id checks and should not be
allowed. Detect this condition at create time and fail with EINVAL.
Fixes: 193125dbd8eb ("net: Introduce VRF device driver") Reported-by: Frank Kellermann <frank.kellermann@atos.net> Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Russell King [Tue, 10 Jan 2017 23:13:45 +0000 (23:13 +0000)]
net: phy: marvell: fix Marvell 88E1512 used in SGMII mode
When an Marvell 88E1512 PHY is connected to a nic in SGMII mode, the
fiber page is used for the SGMII host-side connection. The PHY driver
notices that SUPPORTED_FIBRE is set, so it tries reading the fiber page
for the link status, and ends up reading the MAC-side status instead of
the outgoing (copper) link. This leads to incorrect results reported
via ethtool.
If the PHY is connected via SGMII to the host, ignore the fiber page.
However, continue to allow the existing power management code to
suspend and resume the fiber page.
Fixes: 6cfb3bcc0641 ("Marvell phy: check link status in case of fiber link.") Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
Colin Ian King [Tue, 10 Jan 2017 22:53:06 +0000 (22:53 +0000)]
sctp: Fix spelling mistake: "Atempt" -> "Attempt"
Trivial fix to spelling mistake in WARN_ONCE message
Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
David Ahern [Tue, 10 Jan 2017 22:37:35 +0000 (14:37 -0800)]
net: ipv4: Fix multipath selection with vrf
fib_select_path does not call fib_select_multipath if oif is set in the
flow struct. For VRF use cases oif is always set, so multipath route
selection is bypassed. Use the FLOWI_FLAG_SKIP_NH_OIF to skip the oif
check similar to what is done in fib_table_lookup.
Add saddr and proto to the flow struct for the fib lookup done by the
VRF driver to better match hash computation for a flow.
Fixes: 613d09b30f8b ("net: Use VRF device index for lookups on TX") Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Arnd Bergmann [Tue, 10 Jan 2017 12:08:06 +0000 (13:08 +0100)]
cgroup: move CONFIG_SOCK_CGROUP_DATA to init/Kconfig
We now 'select SOCK_CGROUP_DATA' but Kconfig complains that this is
not right when CONFIG_NET is disabled and there is no socket interface:
warning: (CGROUP_BPF) selects SOCK_CGROUP_DATA which has unmet direct dependencies (NET)
I don't know what the correct solution for this is, but simply removing
the dependency on NET from SOCK_CGROUP_DATA by moving it out of the
'if NET' section avoids the warning and does not produce other build
errors.
Fixes: 483c4933ea09 ("cgroup: Fix CGROUP_BPF config") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet [Wed, 11 Jan 2017 03:52:43 +0000 (19:52 -0800)]
gro: use min_t() in skb_gro_reset_offset()
On 32bit arches, (skb->end - skb->data) is not 'unsigned int',
so we shall use min_t() instead of min() to avoid a compiler error.
Fixes: 1272ce87fa01 ("gro: Enter slow-path if there is no tailroom") Reported-by: kernel test robot <fengguang.wu@intel.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Huang Shijie [Wed, 11 Jan 2017 06:02:00 +0000 (14:02 +0800)]
arm64: hugetlb: fix the wrong return value for huge_ptep_set_access_flags
In current code, the @changed always returns the last one's status for
the huge page with the contiguous bit set. This is really not what we
want. Even one of the PTEs is changed, we should tell it to the caller.
David S. Miller [Wed, 11 Jan 2017 02:34:03 +0000 (21:34 -0500)]
Merge branch 'mlx5-fixes'
Saeed Mahameed says:
====================
Mellanox mlx5 fixes and cleanups 2017-01-10
This series includes some mlx5e general cleanups from Daniel, Gil, Hadar
and myself.
Also it includes some critical mlx5e TC offloads fixes from Or Gerlitz.
For -stable:
- net/mlx5e: Remove WARN_ONCE from adaptive moderation code
Although this fix doesn't affect any functionality, I thought it is
better to clean this -WARN_ONCE- up for -stable in case someone hits
such corner case.
Please apply and let me know if there's any problem.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Jurgens [Tue, 10 Jan 2017 20:33:39 +0000 (22:33 +0200)]
net/mlx5: Only cancel recovery work when cleaning up device
Do not attempt to drain the health workqueue when unloading the device in
the recovery flow, this can cause a deadlock when the recovery work
tries to cancel itself with sync.
Because the work is no longer unconditionally canceled when unloading, it
must be explicitly canceled in the AER flow.
fixes: 689a248df83b ("net/mlx5: Cancel recovery work in remove flow") Signed-off-by: Daniel Jurgens <danielj@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Gil Rockah [Tue, 10 Jan 2017 20:33:38 +0000 (22:33 +0200)]
net/mlx5e: Remove WARN_ONCE from adaptive moderation code
When trying to do interface down or changing interface configuration
under heavy traffic, some of the adaptive moderation corner cases can
occur and leave a WARN_ONCE call trace in the kernel log.
Those WARN_ONCE are meant for debug only, and should have been inserted
only under debug. We avoid such call traces by removing those WARN_ONCE.
Fixes: cb3c7fd4f839 ("net/mlx5e: Support adaptive RX coalescing") Signed-off-by: Gil Rockah <gilr@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Saeed Mahameed [Tue, 10 Jan 2017 20:33:37 +0000 (22:33 +0200)]
net/mlx5e: Un-register uplink representor on nic_disable
The code before this patch registered uplink e-Switch representor
on nic_enable and unregistered on nic_cleanup, the right place
for this unregister is in nic_disable.
Fixes: 127ea380acc9 ("net/mlx5: Add Representors registration API") Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Reviewed-by: Mohamad Haj Yahia <mohamad@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Or Gerlitz [Tue, 10 Jan 2017 20:33:36 +0000 (22:33 +0200)]
net/mlx5e: Properly handle FW errors while adding TC rules
When the firmware returns an error (common example is an attempt to
add twice the same rule which is refused by the some FWs), we are not
properly derefing/cleaning few resources allocated on the way.
Examples are vport vlan deref under eswitch vlan offloads, and encap
entry/neighbour deref under eswitch encapsulation offloads, fix that.
Fixes: a54e20b4fcae ('net/mlx5e: Add basic TC tunnel set action for SRIOV offloads') Fixes: 8b32580df1cb ('net/mlx5e: Add TC vlan action for SRIOV offloads') Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Roi Dayan <roid@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Hadar Hen Zion [Tue, 10 Jan 2017 20:33:35 +0000 (22:33 +0200)]
net/mlx5e: Fix kbuild warnings for uninitialized parameters
kbuild warn about parameters that may be used uninitialized, fix it.
Fixes: a54e20b4fcae ('net/mlx5e: Add basic TC tunnel set action for SRIOV offloads') Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Or Gerlitz [Tue, 10 Jan 2017 20:33:34 +0000 (22:33 +0200)]
net/mlx5e: Set inline mode requirements for matching on IP fragments
For e-switch level matching on packets being an IP fragment, we
need to make sure the source vport inline mode is L3, fix that.
Fixes: 3f7d0eb42d59 ('net/mlx5e: Offload TC matching on packets being IP fragments') Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Roi Dayan <roid@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Or Gerlitz [Tue, 10 Jan 2017 20:33:33 +0000 (22:33 +0200)]
net/mlx5e: Properly get address type of encapsulation IP headers
As done elsewhere in our TC/flower offload code, the address type of
the encapsulation IP headers should be realized accroding to the
addr_type field of the encapsulation control dissector key, do that.
Fixes: bbd00f7e2349 ('net/mlx5e: Add TC tunnel release action for SRIOV offloads') Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Hadar Hen Zion <hadarh@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
When the route lookup fails we should return the actual error.
When the neigh isn't valid, we should return -EOPNOTSUPP as done
in similar cases along the code.
When the offload can't take place as of invalid neigh etc, we
must release the neigh.
Fixes: a54e20b4fcae ('net/mlx5e: Add basic TC tunnel set action for SRIOV offloads') Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Hadar Hen Zion <hadarh@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Or Gerlitz [Tue, 10 Jan 2017 20:33:31 +0000 (22:33 +0200)]
net/mlx5e: Warn when rejecting offload attempts of IP tunnels
We silently reject offloading of IPv6 tunnels, non vxlan tunnels,
vxlan tunnels where the dst port to match is not provided, etc.
Be a bit more verbose and print a warning so the user better
realizes what went wrong here and can fix it.
Fixes: a54e20b4fcae ('net/mlx5e: Add basic TC tunnel set action for SRIOV offloads') Fixes: bbd00f7e2349 ('net/mlx5e: Add TC tunnel release action for SRIOV offloads') Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Hadar Hen Zion <hadarh@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Or Gerlitz [Tue, 10 Jan 2017 20:33:30 +0000 (22:33 +0200)]
net/mlx5e: Properly handle offloading of source udp port for IP tunnels
We can offload the matching on source udp port of ip tunnels for
decapsulation. We can not offload setting source udp port for tunnels
as part of encapsulation. Fix both the code that deals with matching
offload (decap) and the code that deal with encap offload to align with
that.
Fixes: a54e20b4fcae ('net/mlx5e: Add basic TC tunnel set action for SRIOV offloads') Fixes: bbd00f7e2349 ('net/mlx5e: Add TC tunnel release action for SRIOV offloads') Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Hadar Hen Zion <hadarh@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Mike Frysinger [Wed, 11 Jan 2017 00:58:30 +0000 (16:58 -0800)]
timerfd: export defines to userspace
Since userspace is expected to call timerfd syscalls directly with these
flags/ioctls, make sure we export them so they don't have to duplicate
the values themselves.
Link: http://lkml.kernel.org/r/20161219064052.7196-1-vapier@gentoo.org Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Kravetz [Wed, 11 Jan 2017 00:58:27 +0000 (16:58 -0800)]
mm/hugetlb.c: fix reservation race when freeing surplus pages
return_unused_surplus_pages() decrements the global reservation count,
and frees any unused surplus pages that were backing the reservation.
Commit 7848a4bf51b3 ("mm/hugetlb.c: add cond_resched_lock() in
return_unused_surplus_pages()") added a call to cond_resched_lock in the
loop freeing the pages.
As a result, the hugetlb_lock could be dropped, and someone else could
use the pages that will be freed in subsequent iterations of the loop.
This could result in inconsistent global hugetlb page state, application
api failures (such as mmap) failures or application crashes.
When dropping the lock in return_unused_surplus_pages, make sure that
the global reservation count (resv_huge_pages) remains sufficiently
large to prevent someone else from claiming pages about to be freed.
Analyzed by Paul Cassella.
Fixes: 7848a4bf51b3 ("mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()") Link: http://lkml.kernel.org/r/1483991767-6879-1-git-send-email-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reported-by: Paul Cassella <cassella@cray.com> Suggested-by: Michal Hocko <mhocko@kernel.org> Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: <stable@vger.kernel.org> [3.15+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes a bug in the freelist randomization code. When a high
random number is used, the freelist will contain duplicate entries. It
will result in different allocations sharing the same chunk.
It will result in odd behaviours and crashes. It should be uncommon but
it depends on the machines. We saw it happening more often on some
machines (every few hours of running tests).
Fixes: c7ce4f60ac19 ("mm: SLAB freelist randomization") Link: http://lkml.kernel.org/r/20170103181908.143178-1-thgarnie@google.com Signed-off-by: John Sperbeck <jsperbeck@google.com> Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Wed, 11 Jan 2017 00:58:21 +0000 (16:58 -0800)]
zram: support BDI_CAP_STABLE_WRITES
zram has used per-cpu stream feature from v4.7. It aims for increasing
cache hit ratio of scratch buffer for compressing. Downside of that
approach is that zram should ask memory space for compressed page in
per-cpu context which requires stricted gfp flag which could be failed.
If so, it retries to allocate memory space out of per-cpu context so it
could get memory this time and compress the data again, copies it to the
memory space.
In this scenario, zram assumes the data should never be changed but it is
not true without stable page support. So, If the data is changed under
us, zram can make buffer overrun so that zsmalloc free object chain is
broken so system goes crash like below
https://bugzilla.suse.com/show_bug.cgi?id=997574
This patch adds BDI_CAP_STABLE_WRITES to zram for declaring "I am block
device needing *stable write*".
Fixes: da9556a2367c ("zram: user per-cpu compression streams") Link: http://lkml.kernel.org/r/1482366980-3782-4-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Hyeoncheol Lee <cheol.lee@lge.com> Cc: <yjay.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Cc: Hugh Dickins <hughd@google.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: <stable@vger.kernel.org> [4.7+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Minchan Kim [Wed, 11 Jan 2017 00:58:18 +0000 (16:58 -0800)]
zram: revalidate disk under init_lock
Commit b4c5c60920e3 ("zram: avoid lockdep splat by revalidate_disk")
moved revalidate_disk call out of init_lock to avoid lockdep
false-positive splat. However, commit 08eee69fcf6b ("zram: remove
init_lock in zram_make_request") removed init_lock in IO path so there
is no worry about lockdep splat. So, let's restore it.
This patch is needed to set BDI_CAP_STABLE_WRITES atomically in next
patch.
Fixes: da9556a2367c ("zram: user per-cpu compression streams") Link: http://lkml.kernel.org/r/1482366980-3782-3-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Hyeoncheol Lee <cheol.lee@lge.com> Cc: <yjay.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Cc: Hugh Dickins <hughd@google.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: <stable@vger.kernel.org> [4.7+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With investigation, it reveals currently stable page doesn't support
anonymous page. IOW, reuse_swap_page can reuse the page without waiting
writeback completion so it can overwrite page zram is compressing.
Unfortunately, zram has used per-cpu stream feature from v4.7.
It aims for increasing cache hit ratio of scratch buffer for
compressing. Downside of that approach is that zram should ask
memory space for compressed page in per-cpu context which requires
stricted gfp flag which could be failed. If so, it retries to
allocate memory space out of per-cpu context so it could get memory
this time and compress the data again, copies it to the memory space.
In this scenario, zram assumes the data should never be changed
but it is not true unless stable page supports. So, If the data is
changed under us, zram can make buffer overrun because second
compression size could be bigger than one we got in previous trial
and blindly, copy bigger size object to smaller buffer which is
buffer overrun. The overrun breaks zsmalloc free object chaining
so system goes crash like above.
I think below is same problem.
https://bugzilla.suse.com/show_bug.cgi?id=997574
Unfortunately, reuse_swap_page should be atomic so that we cannot wait on
writeback in there so the approach in this patch is simply return false if
we found it needs stable page. Although it increases memory footprint
temporarily, it happens rarely and it should be reclaimed easily althoug
it happened. Also, It would be better than waiting of IO completion,
which is critial path for application latency.
Fixes: da9556a2367c ("zram: user per-cpu compression streams") Link: http://lkml.kernel.org/r/20161120233015.GA14113@bbox Link: http://lkml.kernel.org/r/1482366980-3782-2-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Hugh Dickins <hughd@google.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Hyeoncheol Lee <cheol.lee@lge.com> Cc: <yjay.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Cc: <stable@vger.kernel.org> [4.7+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alexander Duyck [Wed, 11 Jan 2017 00:58:12 +0000 (16:58 -0800)]
mm: add documentation for page fragment APIs
This is a first pass at trying to add documentation for the page_frag
APIs. They may still change over time but for now I thought I would try
to get these documented so that as more network drivers and stack calls
make use of them we have one central spot to document how they are meant
to be used.
Alexander Duyck [Wed, 11 Jan 2017 00:58:09 +0000 (16:58 -0800)]
mm: rename __page_frag functions to __page_frag_cache, drop order from drain
This patch does two things.
First it goes through and renames the __page_frag prefixed functions to
__page_frag_cache so that we can be clear that we are draining or
refilling the cache, not the frags themselves.
Second we drop the order parameter from __page_frag_cache_drain since we
don't actually need to pass it since all fragments are either order 0 or
must be a compound page.
Alexander Duyck [Wed, 11 Jan 2017 00:58:06 +0000 (16:58 -0800)]
mm: rename __alloc_page_frag to page_frag_alloc and __free_page_frag to page_frag_free
Patch series "Page fragment updates", v4.
This patch series takes care of a few cleanups for the page fragments
API.
First we do some renames so that things are much more consistent. First
we move the page_frag_ portion of the name to the front of the functions
names. Secondly we split out the cache specific functions from the
other page fragment functions by adding the word "cache" to the name.
Finally I added a bit of documentation that will hopefully help to
explain some of this. I plan to revisit this later as we get things
more ironed out in the near future with the changes planned for the DMA
setup to support eXpress Data Path.
This patch (of 3):
This patch renames the page frag functions to be more consistent with
other APIs. Specifically we place the name page_frag first in the name
and then have either an alloc or free call name that we append as the
suffix. This makes it a bit clearer in terms of naming.
In addition we drop the leading double underscores since we are
technically no longer a backing interface and instead the front end that
is called from the networking APIs.
the oom killer is clearly pre-mature because there there is still a lot
of page cache in the zone Normal which should satisfy this lowmem
request. Further debugging has shown that the reclaim cannot make any
forward progress because the page cache is hidden in the active list
which doesn't get rotated because inactive_list_is_low is not memcg
aware.
The code simply subtracts per-zone highmem counters from the respective
memcg's lru sizes which doesn't make any sense. We can simply end up
always seeing the resulting active and inactive counts 0 and return
false. This issue is not limited to 32b kernels but in practice the
effect on systems without CONFIG_HIGHMEM would be much harder to notice
because we do not invoke the OOM killer for allocations requests
targeting < ZONE_NORMAL.
Fix the issue by tracking per zone lru page counts in mem_cgroup_per_node
and subtract per-memcg highmem counts when memcg is enabled. Introduce
helper lruvec_zone_lru_size which redirects to either zone counters or
mem_cgroup_get_zone_lru_size when appropriate.
We are losing empty LRU but non-zero lru size detection introduced by ca707239e8a7 ("mm: update_lru_size warn and reset bad lru_size") because
of the inherent zone vs. node discrepancy.
Fixes: f8d1a31163fc ("mm: consider whether to decivate based on eligible zones inactive ratio") Link: http://lkml.kernel.org/r/20170104100825.3729-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Nils Holland <nholland@tisys.org> Tested-by: Nils Holland <nholland@tisys.org> Reported-by: Klaus Ethgen <Klaus@Ethgen.de> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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