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Message-ID: <CA+icZUUqDxwf8eEXfdB_ESAUXt0dcbvO4ByukRDfirPCLnwhFQ@mail.gmail.com>
Date: Wed, 30 Mar 2016 11:20:11 +0200
From: Sedat Dilek <sedat.dilek@...il.com>
To: Ingo Molnar <mingo@...nel.org>
Cc: Peter Zijlstra <peterz@...radead.org>,
Alfredo Alvarez Fernandez <alfredoalvarezfernandez@...il.com>,
Linus Torvalds <torvalds@...ux-foundation.org>,
"Theodore Ts'o" <tytso@....edu>,
linux-fsdevel <linux-fsdevel@...r.kernel.org>,
LKML <linux-kernel@...r.kernel.org>,
Sasha Levin <sasha.levin@...cle.com>
Subject: Re: [Linux-v4.6-rc1] ext4: WARNING: CPU: 2 PID: 2692 at
kernel/locking/lockdep.c:2017 __lock_acquire+0x180e/0x2260
On Tue, Mar 29, 2016 at 10:47 AM, Ingo Molnar <mingo@...nel.org> wrote:
>
> * Peter Zijlstra <peterz@...radead.org> wrote:
>
>> On Sun, Mar 27, 2016 at 05:03:44AM -0700, Linus Torvalds wrote:
>> > Anyway, I don't think that DEBUG_LOCKS_WARN_ON() in
>> >
>> > kernel/locking/lockdep.c:2017 __lock_acquire
>> >
>> > would be an ext4 issue, it looks more like an internal lockdep issue.
>> >
>> > Adding in the lockdep people, who will set me right.
>>
>> You are right; this is lockdep running into a hash collision; which is a new
>> DEBUG_LOCKDEP test. See 9e4e7554e755 ("locking/lockdep: Detect chain_key
>> collisions").
>
> I've Cc:-ed Alfredo Alvarez Fernandez who added that test.
>
> Thanks,
>
[ CC Sasha (liblockdep maintainer) ]
I have added CONFIG_DEBUG_LOCKING_API_SELFTESTS=y to my 6th kernel-run.
$ egrep -i 'lockdep|locking' /boot/config-4.6.0-rc1-6-iniza-small
CONFIG_LOCKDEP_SUPPORT=y
CONFIG_FILE_LOCKING=y
CONFIG_MANDATORY_FILE_LOCKING=y
CONFIG_PROVE_LOCKING=y
CONFIG_LOCKDEP=y
CONFIG_DEBUG_LOCKDEP=y
CONFIG_DEBUG_LOCKING_API_SELFTESTS=y
[ 0.000000] | Locking API testsuite:
[ 0.000000] ----------------------------------------------------------------------------
[ 0.000000] | spin |wlock |rlock
|mutex | wsem | rsem |
[ 0.000000]
--------------------------------------------------------------------------
[ 0.000000] A-A deadlock: ok | ok | ok |
ok | ok | ok |
[ 0.000000] A-B-B-A deadlock: ok | ok | ok |
ok | ok | ok |
[ 0.000000] A-B-B-C-C-A deadlock: ok | ok | ok |
ok | ok | ok |
[ 0.000000] A-B-C-A-B-C deadlock: ok | ok | ok |
ok | ok | ok |
[ 0.000000] A-B-B-C-C-D-D-A deadlock: ok | ok | ok |
ok | ok | ok |
[ 0.000000] A-B-C-D-B-D-D-A deadlock: ok | ok | ok |
ok | ok | ok |
[ 0.000000] A-B-C-D-B-C-D-A deadlock: ok | ok | ok |
ok | ok | ok |
[ 0.000000] double unlock: ok | ok | ok |
ok | ok | ok |
[ 0.000000] initialize held: ok | ok | ok |
ok | ok | ok |
[ 0.000000] bad unlock order: ok | ok | ok |
ok | ok | ok |
[ 0.000000]
--------------------------------------------------------------------------
[ 0.000000] recursive read-lock: | ok |
| ok |
[ 0.000000] recursive read-lock #2: | ok |
| ok |
[ 0.000000] mixed read-write-lock: | ok |
| ok |
[ 0.000000] mixed write-read-lock: | ok |
| ok |
[ 0.000000]
--------------------------------------------------------------------------
[ 0.000000] hard-irqs-on + irq-safe-A/12: ok | ok | ok |
[ 0.000000] soft-irqs-on + irq-safe-A/12: ok | ok | ok |
[ 0.000000] hard-irqs-on + irq-safe-A/21: ok | ok | ok |
[ 0.000000] soft-irqs-on + irq-safe-A/21: ok | ok | ok |
[ 0.000000] sirq-safe-A => hirqs-on/12: ok | ok | ok |
[ 0.000000] sirq-safe-A => hirqs-on/21: ok | ok | ok |
[ 0.000000] hard-safe-A + irqs-on/12: ok | ok | ok |
[ 0.000000] soft-safe-A + irqs-on/12: ok | ok | ok |
[ 0.000000] hard-safe-A + irqs-on/21: ok | ok | ok |
[ 0.000000] soft-safe-A + irqs-on/21: ok | ok | ok |
[ 0.000000] hard-safe-A + unsafe-B #1/123: ok | ok | ok |
[ 0.000000] soft-safe-A + unsafe-B #1/123: ok | ok | ok |
[ 0.000000] hard-safe-A + unsafe-B #1/132: ok | ok | ok |
[ 0.000000] soft-safe-A + unsafe-B #1/132: ok | ok | ok |
[ 0.000000] hard-safe-A + unsafe-B #1/213: ok | ok | ok |
[ 0.000000] soft-safe-A + unsafe-B #1/213: ok | ok | ok |
[ 0.000000] hard-safe-A + unsafe-B #1/231: ok | ok | ok |
[ 0.000000] soft-safe-A + unsafe-B #1/231: ok | ok | ok |
[ 0.000000] hard-safe-A + unsafe-B #1/312: ok | ok | ok |
[ 0.000000] soft-safe-A + unsafe-B #1/312: ok | ok | ok |
[ 0.000000] hard-safe-A + unsafe-B #1/321: ok | ok | ok |
[ 0.000000] soft-safe-A + unsafe-B #1/321: ok | ok | ok |
[ 0.000000] hard-safe-A + unsafe-B #2/123: ok | ok | ok |
[ 0.000000] soft-safe-A + unsafe-B #2/123: ok | ok | ok |
[ 0.000000] hard-safe-A + unsafe-B #2/132: ok | ok | ok |
[ 0.000000] soft-safe-A + unsafe-B #2/132: ok | ok | ok |
[ 0.000000] hard-safe-A + unsafe-B #2/213: ok | ok | ok |
[ 0.000000] soft-safe-A + unsafe-B #2/213: ok | ok | ok |
[ 0.000000] hard-safe-A + unsafe-B #2/231: ok | ok | ok |
[ 0.000000] soft-safe-A + unsafe-B #2/231: ok | ok | ok |
[ 0.000000] hard-safe-A + unsafe-B #2/312: ok | ok | ok |
[ 0.000000] soft-safe-A + unsafe-B #2/312: ok | ok | ok |
[ 0.000000] hard-safe-A + unsafe-B #2/321: ok | ok | ok |
[ 0.000000] soft-safe-A + unsafe-B #2/321: ok | ok | ok |
[ 0.000000] hard-irq lock-inversion/123: ok | ok | ok |
[ 0.000000] soft-irq lock-inversion/123: ok | ok | ok |
[ 0.000000] hard-irq lock-inversion/132: ok | ok | ok |
[ 0.000000] soft-irq lock-inversion/132: ok | ok | ok |
[ 0.000000] hard-irq lock-inversion/213: ok | ok | ok |
[ 0.000000] soft-irq lock-inversion/213: ok | ok | ok |
[ 0.000000] hard-irq lock-inversion/231: ok | ok | ok |
[ 0.000000] soft-irq lock-inversion/231: ok | ok | ok |
[ 0.000000] hard-irq lock-inversion/312: ok | ok | ok |
[ 0.000000] soft-irq lock-inversion/312: ok | ok | ok |
[ 0.000000] hard-irq lock-inversion/321: ok | ok | ok |
[ 0.000000] soft-irq lock-inversion/321: ok | ok | ok |
[ 0.000000] hard-irq read-recursion/123: ok |
[ 0.000000] soft-irq read-recursion/123: ok |
[ 0.000000] hard-irq read-recursion/132: ok |
[ 0.000000] soft-irq read-recursion/132: ok |
[ 0.000000] hard-irq read-recursion/213: ok |
[ 0.000000] soft-irq read-recursion/213: ok |
[ 0.000000] hard-irq read-recursion/231: ok |
[ 0.000000] soft-irq read-recursion/231: ok |
[ 0.000000] hard-irq read-recursion/312: ok |
[ 0.000000] soft-irq read-recursion/312: ok |
[ 0.000000] hard-irq read-recursion/321: ok |
[ 0.000000] soft-irq read-recursion/321: ok |
[ 0.000000]
--------------------------------------------------------------------------
[ 0.000000] | Wound/wait tests |
[ 0.000000] ---------------------
[ 0.000000] ww api failures: ok | ok | ok |
[ 0.000000] ww contexts mixing: ok | ok |
[ 0.000000] finishing ww context: ok | ok | ok | ok |
[ 0.000000] locking mismatches: ok | ok | ok |
[ 0.000000] EDEADLK handling: ok | ok | ok |
ok | ok | ok | ok | ok | ok | ok |
[ 0.000000] spinlock nest unlocked: ok |
[ 0.000000] -----------------------------------------------------
[ 0.000000] |block | try |context|
[ 0.000000] -----------------------------------------------------
[ 0.000000] context: ok | ok | ok |
[ 0.000000] try: ok | ok | ok |
[ 0.000000] block: ok | ok | ok |
[ 0.000000] spinlock: ok | ok | ok |
[ 0.000000] -------------------------------------------------------
[ 0.000000] Good, all 253 testcases passed! |
[ 0.000000] ---------------------------------
And it's all good?
( On shutdown I saw an(other) issue - will investigate, might not be related. )
With my patch "
liblockdep: Fix unsupported 'basename -s' in run_tests.sh" (see
<https://patchwork.kernel.org/patch/8693641/>),
tools/lib/lockdep/run_tests.sh runs fine, now.
$ cd linux/
$ LC_ALL=C make -C tools/ liblockdep
make: Entering directory `/home/wearefam/src/linux-kernel/linux/tools'
DESCEND lib/lockdep
make[1]: Entering directory
`/home/wearefam/src/linux-kernel/linux/tools/lib/lockdep'
CC fixdep.o
LD fixdep-in.o
LINK fixdep
CC common.o
CC lockdep.o
CC preload.o
CC rbtree.o
LD liblockdep-in.o
LD liblockdep.a
LD liblockdep.so.4.6.0-rc1
make[1]: Leaving directory
`/home/wearefam/src/linux-kernel/linux/tools/lib/lockdep'
make: Leaving directory `/home/wearefam/src/linux-kernel/linux/tools'
$ cd tools/lib/lockdep/
$ LC_ALL=C ./run_tests.sh
AA... PASSED!
ABA... PASSED!
ABBA... PASSED!
ABBA_2threads... PASSED!
ABBCCA... PASSED!
ABBCCDDA... PASSED!
ABCABC... PASSED!
ABCDBCDA... PASSED!
ABCDBDDA... PASSED!
WW... PASSED!
unlock_balance... PASSED!
(PRELOAD) AA... PASSED!
(PRELOAD) ABA... PASSED!
(PRELOAD) ABBA... PASSED!
(PRELOAD) ABBA_2threads... PASSED!
(PRELOAD) ABBCCA... PASSED!
(PRELOAD) ABBCCDDA... PASSED!
(PRELOAD) ABCABC... PASSED!
(PRELOAD) ABCDBCDA... PASSED!
(PRELOAD) ABCDBDDA... PASSED!
(PRELOAD) WW... PASSED!
(PRELOAD) unlock_balance... PASSED!
Thanks for all involved people (another interesting issue was caught
while dealing with this issue).
Linux-config and dmesg-log attached.
- Sedat -
View attachment "dmesg_4.6.0-rc1-6-iniza-small.txt" of type "text/plain" (63534 bytes)
Download attachment "config-4.6.0-rc1-6-iniza-small" of type "application/octet-stream" (134966 bytes)
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