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| author | Manfred Spraul | 2013-07-09 01:01:25 +0200 |
|---|---|---|
| committer | Linus Torvalds | 2013-07-09 19:33:28 +0200 |
| commit | d12e1e50e47e0900dbbf52237b7e171f4f15ea1e (patch) | |
| tree | 83b54585a883ee062353eb464d93944d08ab4a1c /COPYING | |
| parent | ipc/sem.c: always use only one queue for alter operations (diff) | |
| download | kernel-qcow2-linux-d12e1e50e47e0900dbbf52237b7e171f4f15ea1e.tar.gz kernel-qcow2-linux-d12e1e50e47e0900dbbf52237b7e171f4f15ea1e.tar.xz kernel-qcow2-linux-d12e1e50e47e0900dbbf52237b7e171f4f15ea1e.zip | |
ipc/sem.c: replace shared sem_otime with per-semaphore value
sem_otime contains the time of the last semaphore operation that
completed successfully. Every operation updates this value, thus access
from multiple cpus can cause thrashing.
Therefore the patch replaces the variable with a per-semaphore variable.
The per-array sem_otime is only calculated when required.
No performance improvement on a single-socket i3 - only important for
larger systems.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'COPYING')
0 files changed, 0 insertions, 0 deletions