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  1. 14 Nov, 2014 3 commits
    • Joonsoo Kim's avatar
      mm/page_alloc: fix incorrect isolation behavior by rechecking migratetype · ad53f92e
      Joonsoo Kim authored 
      Before describing bugs itself, I first explain definition of freepage.

 1. pages on buddy list are counted as freepage.
 2. pages on isolate migratetype buddy list are *not* counted as freepage.
 3. pages on cma buddy list are counted as CMA freepage, too.

Now, I describe problems and related patch.

Patch 1: There is race conditions on getting pageblock migratetype that
it results in misplacement of freepages on buddy list, incorrect
freepage count and un-availability of freepage.

Patch 2: Freepages on pcp list could have stale cached information to
determine migratetype of buddy list to go.  This causes misplacement of
freepages on buddy list and incorrect freepage count.

Patch 4: Merging between freepages on different migratetype of
pageblocks will cause freepages accouting problem.  This patch fixes it.

Without patchset [3], above problem doesn't happens on my CMA allocation
test, because CMA reserved pages aren't used at all.  So there is no
chance for above race.

With patchset [3], I did simple CMA allocation test and get below
result:

 - Virtual machine, 4 cpus, 1024 MB memory, 256 MB CMA reservation
 - run kernel build (make -j16) on background
 - 30 times CMA allocation(8MB * 30 = 240MB) attempts in 5 sec interval
 - Result: more than 5000 freepage count are missed

With patchset [3] and this patchset, I found that no freepage count are
missed so that I conclude that problems are solved.

On my simple memory offlining test, these problems also occur on that
environment, too.

This patch (of 4):

There are two paths to reach core free function of buddy allocator,
__free_one_page(), one is free_one_page()->__free_one_page() and the
other is free_hot_cold_page()->free_pcppages_bulk()->__free_one_page().
Each paths has race condition causing serious problems.  At first, this
patch is focused on first type of freepath.  And then, following patch
will solve the problem in second type of freepath.

In the first type of freepath, we got migratetype of freeing page
without holding the zone lock, so it could be racy.  There are two cases
of this race.

 1. pages are added to isolate buddy list after restoring orignal
    migratetype

    CPU1                                   CPU2

    get migratetype => return MIGRATE_ISOLATE
    call free_one_page() with MIGRATE_ISOLATE

                                grab the zone lock
                                unisolate pageblock
                                release the zone lock

    grab the zone lock
    call __free_one_page() with MIGRATE_ISOLATE
    freepage go into isolate buddy list,
    although pageblock is already unisolated

This may cause two problems.  One is that we can't use this page anymore
until next isolation attempt of this pageblock, because freepage is on
isolate buddy list.  The other is that freepage accouting could be wrong
due to merging between different buddy list.  Freepages on isolate buddy
list aren't counted as freepage, but ones on normal buddy list are
counted as freepage.  If merge happens, buddy freepage on normal buddy
list is inevitably moved to isolate buddy list without any consideration
of freepage accouting so it could be incorrect.

 2. pages are added to normal buddy list while pageblock is isolated.
    It is similar with above case.

This also may cause two problems.  One is that we can't keep these
freepages from being allocated.  Although this pageblock is isolated,
freepage would be added to normal buddy list so that it could be
allocated without any restriction.  And the other problem is same as
case 1, that it, incorrect freepage accouting.

This race condition would be prevented by checking migratetype again
with holding the zone lock.  Because it is somewhat heavy operation and
it isn't needed in common case, we want to avoid rechecking as much as
possible.  So this patch introduce new variable, nr_isolate_pageblock in
struct zone to check if there is isolated pageblock.  With this, we can
avoid to re-check migratetype in common case and do it only if there is
isolated pageblock or migratetype is MIGRATE_ISOLATE.  This solve above
mentioned problems.

Changes from v3:
Add one more check in free_one_page() that checks whether migratetype is
MIGRATE_ISOLATE or not. Without this, abovementioned case 1 could happens.
Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: default avatarMinchan Kim <minchan@kernel.org>
Acked-by: default avatarMichal Nazarewicz <mina86@mina86.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Heesub Shin <heesub.shin@samsung.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Ritesh Harjani <ritesh.list@gmail.com>
Cc: Gioh Kim <gioh.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ad53f92e
    • Joonsoo Kim's avatar
      mm/compaction: skip the range until proper target pageblock is met · 58420016
      Joonsoo Kim authored 
      Commit 7d49d886 ("mm, compaction: reduce zone checking frequency in
the migration scanner") has a side-effect that changes the iteration
range calculation.  Before the change, block_end_pfn is calculated using
start_pfn, but now it blindly adds pageblock_nr_pages to the previous
value.

This causes the problem that isolation_start_pfn is larger than
block_end_pfn when we isolate the page with more than pageblock order.
In this case, isolation would fail due to an invalid range parameter.

To prevent this, this patch implements skipping the range until a proper
target pageblock is met.  Without this patch, CMA with more than
pageblock order always fails but with this patch it will succeed.
Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      58420016
    • Weijie Yang's avatar
      zram: avoid kunmap_atomic() of a NULL pointer · c4065152
      Weijie Yang authored 
      zram could kunmap_atomic() a NULL pointer in a rare situation: a zram
page becomes a full-zeroed page after a partial write io.  The current
code doesn't handle this case and performs kunmap_atomic() on a NULL
pointer, which panics the kernel.

This patch fixes this issue.
Signed-off-by: default avatarWeijie Yang <weijie.yang@samsung.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Weijie Yang <weijie.yang.kh@gmail.com>
Acked-by: default avatarJerome Marchand <jmarchan@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c4065152
  3. 13 Nov, 2014 4 commits
  5. 12 Nov, 2014 10 commits
  7. 11 Nov, 2014 5 commits
  9. 10 Nov, 2014 11 commits
    • Rabin Vincent's avatar
      tracing: Do not risk busy looping in buffer splice · 07906da7
      Rabin Vincent authored 
      If the read loop in trace_buffers_splice_read() keeps failing due to
memory allocation failures without reading even a single page then this
function will keep busy looping.

Remove the risk for that by exiting the function if memory allocation
failures are seen.

Link: http://lkml.kernel.org/r/1415309167-2373-2-git-send-email-rabin@rab.inSigned-off-by: default avatarRabin Vincent <rabin@rab.in>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      07906da7
    • Rabin Vincent's avatar
      tracing: Do not busy wait in buffer splice · e30f53aa
      Rabin Vincent authored 
      On a !PREEMPT kernel, attempting to use trace-cmd results in a soft
lockup:

 # trace-cmd record -e raw_syscalls:* -F false
 NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [trace-cmd:61]
 ...
 Call Trace:
  [<ffffffff8105b580>] ? __wake_up_common+0x90/0x90
  [<ffffffff81092e25>] wait_on_pipe+0x35/0x40
  [<ffffffff810936e3>] tracing_buffers_splice_read+0x2e3/0x3c0
  [<ffffffff81093300>] ? tracing_stats_read+0x2a0/0x2a0
  [<ffffffff812d10ab>] ? _raw_spin_unlock+0x2b/0x40
  [<ffffffff810dc87b>] ? do_read_fault+0x21b/0x290
  [<ffffffff810de56a>] ? handle_mm_fault+0x2ba/0xbd0
  [<ffffffff81095c80>] ? trace_event_buffer_lock_reserve+0x40/0x80
  [<ffffffff810951e2>] ? trace_buffer_lock_reserve+0x22/0x60
  [<ffffffff81095c80>] ? trace_event_buffer_lock_reserve+0x40/0x80
  [<ffffffff8112415d>] do_splice_to+0x6d/0x90
  [<ffffffff81126971>] SyS_splice+0x7c1/0x800
  [<ffffffff812d1edd>] tracesys_phase2+0xd3/0xd8

The problem is this: tracing_buffers_splice_read() calls
ring_buffer_wait() to wait for data in the ring buffers.  The buffers
are not empty so ring_buffer_wait() returns immediately.  But
tracing_buffers_splice_read() calls ring_buffer_read_page() with full=1,
meaning it only wants to read a full page.  When the full page is not
available, tracing_buffers_splice_read() tries to wait again with
ring_buffer_wait(), which again returns immediately, and so on.

Fix this by adding a "full" argument to ring_buffer_wait() which will
make ring_buffer_wait() wait until the writer has left the reader's
page, i.e.  until full-page reads will succeed.

Link: http://lkml.kernel.org/r/1415645194-25379-1-git-send-email-rabin@rab.in

Cc: stable@vger.kernel.org # 3.16+
Fixes: b1169cc6 ("tracing: Remove mock up poll wait function")
Signed-off-by: default avatarRabin Vincent <rabin@rab.in>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      e30f53aa
    • Joe Thornber's avatar
      dm btree: fix a recursion depth bug in btree walking code · 9b460d36
      Joe Thornber authored 
      The walk code was using a 'ro_spine' to hold it's locked btree nodes.
But this data structure is designed for the rolling lock scheme, and
as such automatically unlocks blocks that are two steps up the call
chain.  This is not suitable for the simple recursive walk algorithm,
which retraces its steps.

This code is only used by the persistent array code, which in turn is
only used by dm-cache.  In order to trigger it you need to have a
mapping tree that is more than 2 levels deep; which equates to 8-16
million cache blocks.  For instance a 4T ssd with a very small block
size of 32k only just triggers this bug.

The fix just places the locked blocks on the stack, and stops using
the ro_spine altogether.
Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
      9b460d36
    • Tony Lindgren's avatar
      mfd: twl4030-power: Fix poweroff with PM configuration enabled · 481c7f86
      Tony Lindgren authored 
      Commit e7cd1d1e ("mfd: twl4030-power: Add generic reset
configuration") enabled configuring the PM features for twl4030.

This caused poweroff command to fail on devices that have the
BCI charger on twl4030 wired, or have power wired for VBUS.
Instead of powering off, the device reboots. This is because
voltage is detected on charger or VBUS with the default bits
enabled for the power transition registers.

To fix the issue, let's just clear VBUS and CHG bits as we want
poweroff command to keep the system powered off.

Fixes: e7cd1d1e ("mfd: twl4030-power: Add generic reset configuration")
Cc: stable@vger.kernel.org # v3.16+
Reported-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
      481c7f86
    • Krzysztof Kozlowski's avatar
      mfd: max77693: Fix always masked MUIC interrupts · c0acb814
      Krzysztof Kozlowski authored 
      All interrupts coming from MUIC were ignored because interrupt source
register was masked.

The Maxim 77693 has a "interrupt source" - a separate register and interrupts
which give information about PMIC block triggering the individual
interrupt (charger, topsys, MUIC, flash LED).

By default bootloader could initialize this register to "mask all"
value. In such case (observed on Trats2 board) MUIC interrupts won't be
generated regardless of their mask status. Regmap irq chip was unmasking
individual MUIC interrupts but the source was masked

Before introducing regmap irq chip this interrupt source was unmasked,
read and acked. Reading and acking is not necessary but unmasking is.

Fixes: 342d669c ("mfd: max77693: Handle IRQs using regmap")

Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
      c0acb814
    • Krzysztof Kozlowski's avatar
      mfd: max77693: Use proper regmap for handling MUIC interrupts · 43fc9396
      Krzysztof Kozlowski authored 
      Interrupts coming from Maxim77693 MUIC block (MicroUSB Interface
Controller) were not handled at all because wrong regmap was used for
MUIC's regmap_irq_chip.

The MUIC component of Maxim 77693 uses different I2C address thus second
regmap is created and used by max77693 extcon driver. The registers for
MUIC interrupts are also in that block and should be handled by that
second regmap.

However the regmap irq chip for MUIC was configured with default regmap
which could not read MUIC registers.

Fixes: 342d669c ("mfd: max77693: Handle IRQs using regmap")

Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
      43fc9396
    • Johan Hovold's avatar
      mfd: viperboard: Fix platform-device id collision · b6684228
      Johan Hovold authored 
      Allow more than one viperboard to be connected by registering with
PLATFORM_DEVID_AUTO instead of PLATFORM_DEVID_NONE.

The subdevices are currently registered with PLATFORM_DEVID_NONE, which
will cause a name collision on the platform bus when a second viperboard
is plugged in:

viperboard 1-2.4:1.0: version 0.00 found at bus 001 address 004
------------[ cut here ]------------
WARNING: CPU: 0 PID: 181 at /home/johan/work/omicron/src/linux/fs/sysfs/dir.c:31 sysfs_warn_dup+0x74/0x84()
sysfs: cannot create duplicate filename '/bus/platform/devices/viperboard-gpio'
Modules linked in: i2c_viperboard viperboard netconsole [last unloaded: viperboard]
CPU: 0 PID: 181 Comm: bash Tainted: G        W      3.17.0-rc6 #1
[<c0016bf4>] (unwind_backtrace) from [<c0013860>] (show_stack+0x20/0x24)
[<c0013860>] (show_stack) from [<c04305f8>] (dump_stack+0x24/0x28)
[<c04305f8>] (dump_stack) from [<c0040fb4>] (warn_slowpath_common+0x80/0x98)
[<c0040fb4>] (warn_slowpath_common) from [<c004100c>] (warn_slowpath_fmt+0x40/0x48)
[<c004100c>] (warn_slowpath_fmt) from [<c016f1bc>] (sysfs_warn_dup+0x74/0x84)
[<c016f1bc>] (sysfs_warn_dup) from [<c016f548>] (sysfs_do_create_link_sd.isra.2+0xcc/0xd0)
[<c016f548>] (sysfs_do_create_link_sd.isra.2) from [<c016f588>] (sysfs_create_link+0x3c/0x48)
[<c016f588>] (sysfs_create_link) from [<c02867ec>] (bus_add_device+0x12c/0x1e0)
[<c02867ec>] (bus_add_device) from [<c0284820>] (device_add+0x410/0x584)
[<c0284820>] (device_add) from [<c0289440>] (platform_device_add+0xd8/0x26c)
[<c0289440>] (platform_device_add) from [<c02a5ae4>] (mfd_add_device+0x240/0x344)
[<c02a5ae4>] (mfd_add_device) from [<c02a5ce0>] (mfd_add_devices+0xb8/0x110)
[<c02a5ce0>] (mfd_add_devices) from [<bf00d1c8>] (vprbrd_probe+0x160/0x1b0 [viperboard])
[<bf00d1c8>] (vprbrd_probe [viperboard]) from [<c030c000>] (usb_probe_interface+0x1bc/0x2a8)
[<c030c000>] (usb_probe_interface) from [<c028768c>] (driver_probe_device+0x14c/0x3ac)
[<c028768c>] (driver_probe_device) from [<c02879e4>] (__driver_attach+0xa4/0xa8)
[<c02879e4>] (__driver_attach) from [<c0285698>] (bus_for_each_dev+0x70/0xa4)
[<c0285698>] (bus_for_each_dev) from [<c0287030>] (driver_attach+0x2c/0x30)
[<c0287030>] (driver_attach) from [<c030a288>] (usb_store_new_id+0x170/0x1ac)
[<c030a288>] (usb_store_new_id) from [<c030a2f8>] (new_id_store+0x34/0x3c)
[<c030a2f8>] (new_id_store) from [<c02853ec>] (drv_attr_store+0x30/0x3c)
[<c02853ec>] (drv_attr_store) from [<c016eaa8>] (sysfs_kf_write+0x5c/0x60)
[<c016eaa8>] (sysfs_kf_write) from [<c016dc68>] (kernfs_fop_write+0xd4/0x194)
[<c016dc68>] (kernfs_fop_write) from [<c010fe40>] (vfs_write+0xb4/0x1c0)
[<c010fe40>] (vfs_write) from [<c01104a8>] (SyS_write+0x4c/0xa0)
[<c01104a8>] (SyS_write) from [<c000f900>] (ret_fast_syscall+0x0/0x48)
---[ end trace 98e8603c22d65817 ]---
viperboard 1-2.4:1.0: Failed to add mfd devices to core.
viperboard: probe of 1-2.4:1.0 failed with error -17
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
      b6684228
    • Thierry Reding's avatar
      mfd: rtsx: Fix build warnings for !PM · 451be648
      Thierry Reding authored 
      rtsx_pci_power_off() is called only from rtsx_pci_suspend(), which isn't
built when PM is disabled.
Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
      451be648
    • Linus Walleij's avatar
      mfd: stmpe: Fix STMPE24xx GPMR LSB · 871c3cf4
      Linus Walleij authored 
      The least significat byte of the GPIO value read register
on the STMPE24xx series is on addres 0xA4 not 0xA5. Correct
against datasheet and tested on the STMPE2401 hardware.
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
      871c3cf4
    • Chris Zankel's avatar
      Merge tag 'v3.18-rc4' into for_next · aeb58973
      Chris Zankel authored 
      Linux 3.18-rc4
      aeb58973
    • Dave Airlie's avatar
      Merge tag 'drm-intel-fixes-2014-11-07' of git://anongit.freedesktop.org/drm-intel into drm-fixes · 03dca708
      Dave Airlie authored 
      Black screen, screen corruption, hardware state corruption fixes.

* tag 'drm-intel-fixes-2014-11-07' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: safeguard against too high minimum brightness
  drm/i915: vlv: fix gunit HW state corruption during S4 suspend
  drm/i915: Disable caches for Global GTT.
      03dca708
  11. 09 Nov, 2014 7 commits
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