2017-11-22 17:48:53

by Sebastian Ott

[permalink] [raw]
Subject: [bisected] system hang after boot

Hi,

One of my test systems (s390) hangs after boot. One of the cpus is idle
the other is in arch_spin_relax. Bisect pointed to this one:

a8a217c22116eff6c120d753c9934089fb229af0 is the first bad commit
commit a8a217c22116eff6c120d753c9934089fb229af0
Author: Will Deacon <[email protected]>
Date: Tue Oct 3 19:25:27 2017 +0100

locking/core: Remove {read,spin,write}_can_lock()

Outside of the locking code itself, {read,spin,write}_can_lock() have no
users in tree. Apparmor (the last remaining user of write_can_lock()) got
moved over to lockdep by the previous patch.

This patch removes the use of {read,spin,write}_can_lock() from the
BUILD_LOCK_OPS macro, deferring to the trylock operation for testing the
lock status, and subsequently removes the unused macros altogether. They
aren't guaranteed to work in a concurrent environment and can give
incorrect results in the case of qrwlock.

Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>


Bisect log and config attached. The same config but with lockdep enabled
works ok.

Sebastian


Attachments:
bisect.log (2.78 kB)
config (56.21 kB)
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