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  1. 16 Nov, 2015 33 commits
  3. 30 Oct, 2015 7 commits
    • Alex Deucher's avatar
      drm/radeon: add pm sysfs files late · 6ce55eb9
      Alex Deucher authored 
      commit 51a4726b upstream.

They were added relatively early in the driver init process
which meant that in some cases the driver was not finished
initializing before external tools tried to use them which
could result in a crash depending on the timing.
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      6ce55eb9
    • Shaohua Li's avatar
      workqueue: make sure delayed work run in local cpu · c7ca6b49
      Shaohua Li authored 
      commit 874bbfe6 upstream.

My system keeps crashing with below message. vmstat_update() schedules a delayed
work in current cpu and expects the work runs in the cpu.
schedule_delayed_work() is expected to make delayed work run in local cpu. The
problem is timer can be migrated with NO_HZ. __queue_work() queues work in
timer handler, which could run in a different cpu other than where the delayed
work is scheduled. The end result is the delayed work runs in different cpu.
The patch makes __queue_delayed_work records local cpu earlier. Where the timer
runs doesn't change where the work runs with the change.

[   28.010131] ------------[ cut here ]------------
[   28.010609] kernel BUG at ../mm/vmstat.c:1392!
[   28.011099] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN
[   28.011860] Modules linked in:
[   28.012245] CPU: 0 PID: 289 Comm: kworker/0:3 Tainted: G        W4.3.0-rc3+ #634
[   28.013065] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153802- 04/01/2014
[   28.014160] Workqueue: events vmstat_update
[   28.014571] task: ffff880117682580 ti: ffff8800ba428000 task.ti: ffff8800ba428000
[   28.015445] RIP: 0010:[<ffffffff8115f921>]  [<ffffffff8115f921>]vmstat_update+0x31/0x80
[   28.016282] RSP: 0018:ffff8800ba42fd80  EFLAGS: 00010297
[   28.016812] RAX: 0000000000000000 RBX: ffff88011a858dc0 RCX:0000000000000000
[   28.017585] RDX: ffff880117682580 RSI: ffffffff81f14d8c RDI:ffffffff81f4df8d
[   28.018366] RBP: ffff8800ba42fd90 R08: 0000000000000001 R09:0000000000000000
[   28.019169] R10: 0000000000000000 R11: 0000000000000121 R12:ffff8800baa9f640
[   28.019947] R13: ffff88011a81e340 R14: ffff88011a823700 R15:0000000000000000
[   28.020071] FS:  0000000000000000(0000) GS:ffff88011a800000(0000)knlGS:0000000000000000
[   28.020071] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[   28.020071] CR2: 00007ff6144b01d0 CR3: 00000000b8e93000 CR4:00000000000006f0
[   28.020071] Stack:
[   28.020071]  ffff88011a858dc0 ffff8800baa9f640 ffff8800ba42fe00ffffffff8106bd88
[   28.020071]  ffffffff8106bd0b 0000000000000096 0000000000000000ffffffff82f9b1e8
[   28.020071]  ffffffff829f0b10 0000000000000000 ffffffff81f18460ffff88011a81e340
[   28.020071] Call Trace:
[   28.020071]  [<ffffffff8106bd88>] process_one_work+0x1c8/0x540
[   28.020071]  [<ffffffff8106bd0b>] ? process_one_work+0x14b/0x540
[   28.020071]  [<ffffffff8106c214>] worker_thread+0x114/0x460
[   28.020071]  [<ffffffff8106c100>] ? process_one_work+0x540/0x540
[   28.020071]  [<ffffffff81071bf8>] kthread+0xf8/0x110
[   28.020071]  [<ffffffff81071b00>] ?kthread_create_on_node+0x200/0x200
[   28.020071]  [<ffffffff81a6522f>] ret_from_fork+0x3f/0x70
[   28.020071]  [<ffffffff81071b00>] ?kthread_create_on_node+0x200/0x200
Signed-off-by: default avatarShaohua Li <shli@fb.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      c7ca6b49
    • Christoph Hellwig's avatar
      3w-9xxx: don't unmap bounce buffered commands · 9dca7991
      Christoph Hellwig authored 
      commit 15e3d5a2 upstream.

3w controller don't dma map small single SGL entry commands but instead
bounce buffer them.  Add a helper to identify these commands and don't
call scsi_dma_unmap for them.

Based on an earlier patch from James Bottomley.

Fixes: 118c85 ("3w-9xxx: fix command completion race")
Reported-by: default avatarTóth Attila <atoth@atoth.sote.hu>
Tested-by: default avatarTóth Attila <atoth@atoth.sote.hu>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarAdam Radford <aradford@gmail.com>
Signed-off-by: default avatarJames Bottomley <JBottomley@Odin.com>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      9dca7991
    • Joe Thornber's avatar
      dm cache: fix NULL pointer when switching from cleaner policy · 495ec73d
      Joe Thornber authored 
      commit 2bffa150 upstream.

The cleaner policy doesn't make use of the per cache block hint space in
the metadata (unlike the other policies).  When switching from the
cleaner policy to mq or smq a NULL pointer crash (in dm_tm_new_block)
was observed.  The crash was caused by bugs in dm-cache-metadata.c
when trying to skip creation of the hint btree.

The minimal fix is to change hint size for the cleaner policy to 4 bytes
(only hint size supported).
Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      495ec73d
    • Peter Zijlstra's avatar
      sched/core: Fix TASK_DEAD race in finish_task_switch() · 206b196c
      Peter Zijlstra authored 
      commit 95913d97 upstream.

So the problem this patch is trying to address is as follows:

        CPU0                            CPU1

        context_switch(A, B)
                                        ttwu(A)
                                          LOCK A->pi_lock
                                          A->on_cpu == 0
        finish_task_switch(A)
          prev_state = A->state  <-.
          WMB                      |
          A->on_cpu = 0;           |
          UNLOCK rq0->lock         |
                                   |    context_switch(C, A)
                                   `--  A->state = TASK_DEAD
          prev_state == TASK_DEAD
            put_task_struct(A)
                                        context_switch(A, C)
                                        finish_task_switch(A)
                                          A->state == TASK_DEAD
                                            put_task_struct(A)

The argument being that the WMB will allow the load of A->state on CPU0
to cross over and observe CPU1's store of A->state, which will then
result in a double-drop and use-after-free.

Now the comment states (and this was true once upon a long time ago)
that we need to observe A->state while holding rq->lock because that
will order us against the wakeup; however the wakeup will not in fact
acquire (that) rq->lock; it takes A->pi_lock these days.

We can obviously fix this by upgrading the WMB to an MB, but that is
expensive, so we'd rather avoid that.

The alternative this patch takes is: smp_store_release(&A->on_cpu, 0),
which avoids the MB on some archs, but not important ones like ARM.
Reported-by: default avatarOleg Nesterov <oleg@redhat.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: manfred@colorfullife.com
Cc: will.deacon@arm.com
Fixes: e4a52bcb ("sched: Remove rq->lock from the first half of ttwu()")
Link: http://lkml.kernel.org/r/20150929124509.GG3816@twins.programming.kicks-ass.netSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      206b196c
    • Mark Salyzyn's avatar
      arm64: readahead: fault retry breaks mmap file read random detection · 42e74492
      Mark Salyzyn authored 
      commit 569ba74a upstream.

This is the arm64 portion of commit 45cac65b ("readahead: fault
retry breaks mmap file read random detection"), which was absent from
the initial port and has since gone unnoticed. The original commit says:

> .fault now can retry.  The retry can break state machine of .fault.  In
> filemap_fault, if page is miss, ra->mmap_miss is increased.  In the second
> try, since the page is in page cache now, ra->mmap_miss is decreased.  And
> these are done in one fault, so we can't detect random mmap file access.
>
> Add a new flag to indicate .fault is tried once.  In the second try, skip
> ra->mmap_miss decreasing.  The filemap_fault state machine is ok with it.

With this change, Mark reports that:

> Random read improves by 250%, sequential read improves by 40%, and
> random write by 400% to an eMMC device with dm crypto wrapped around it.

Cc: Shaohua Li <shli@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: default avatarMark Salyzyn <salyzyn@android.com>
Signed-off-by: default avatarRiley Andrews <riandrews@android.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      42e74492
    • Takashi Iwai's avatar
      ALSA: synth: Fix conflicting OSS device registration on AWE32 · 6be8542e
      Takashi Iwai authored 
      commit 225db576 upstream.

When OSS emulation is loaded on ISA SB AWE32 chip, we get now kernel
warnings like:
  WARNING: CPU: 0 PID: 2791 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x51/0x80()
  sysfs: cannot create duplicate filename '/devices/isa/sbawe.0/sound/card0/seq-oss-0-0'

It's because both emux synth and opl3 drivers try to register their
OSS device object with the same static index number 0.  This hasn't
been a big problem until the recent rewrite of device management code
(that exposes sysfs at the same time), but it's been an obvious bug.

This patch works around it just by using a different index number of
emux synth object.  There can be a more elegant way to fix, but it's
enough for now, as this code won't be touched so often, in anyway.
Reported-and-tested-by: default avatarMichael Shell <list1@michaelshell.org>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      6be8542e
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