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author | Manfred Spraul <manfred@colorfullife.com> | 2013-05-26 11:08:52 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-26 15:14:51 -0700 |
commit | ab465df9dda42a997f7537c875127eeb6a88158c (patch) | |
tree | 28a1ec28c15f1b59c938b7757c8f56eed0de0ecd /Kconfig | |
parent | 89ff77837a67994e4a4a20bb648687fbcc3083f2 (diff) | |
download | lwn-ab465df9dda42a997f7537c875127eeb6a88158c.tar.gz lwn-ab465df9dda42a997f7537c875127eeb6a88158c.zip |
ipc/sem.c: Fix missing wakeups in do_smart_update_queue()
do_smart_update_queue() is called when an operation (semop,
semctl(SETVAL), semctl(SETALL), ...) modified the array. It must check
which of the sleeping tasks can proceed.
do_smart_update_queue() missed a few wakeups:
- if a sleeping complex op was completed, then all per-semaphore queues
must be scanned - not only those that were modified by *sops
- if a sleeping simple op proceeded, then the global queue must be
scanned again
And:
- the test for "|sops == NULL) before scanning the global queue is not
required: If the global queue is empty, then it doesn't need to be
scanned - regardless of the reason for calling do_smart_update_queue()
The patch is not optimized, i.e. even completing a wait-for-zero
operation causes a rescan. This is done to keep the patch as simple as
possible.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Kconfig')
0 files changed, 0 insertions, 0 deletions