linux/ipc
Manfred Spraul d12e1e50e4 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>
2013-07-09 10:33:28 -07:00
..
compat_mq.c ipc: initialize structure memory to zero for compat functions 2010-10-27 18:03:13 -07:00
compat.c get rid of union semop in sys_semctl(2) arguments 2013-03-05 15:14:16 -05:00
ipc_sysctl.c ipc: add sysctl to specify desired next object id 2013-01-04 16:11:45 -08:00
ipcns_notifier.c ipc: do not use a negative value to re-enable msgmni automatic recomputing 2008-07-25 10:53:42 -07:00
Makefile Add generic sys_ipc wrapper 2010-03-12 15:52:32 -08:00
mq_sysctl.c mqueue: separate mqueue default value from maximum value 2012-05-31 17:49:31 -07:00
mqueue.c audit: fix mq_open and mq_unlink to add the MQ root as a hidden parent audit_names record 2013-07-09 10:33:19 -07:00
msg.c ipc: remove unused functions 2013-07-09 10:33:27 -07:00
msgutil.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
namespace.c proc: Split the namespace stuff out into linux/proc_ns.h 2013-05-01 17:29:39 -04:00
sem.c ipc/sem.c: replace shared sem_otime with per-semaphore value 2013-07-09 10:33:28 -07:00
shm.c ipc: move locking out of ipcctl_pre_down_nolock 2013-07-09 10:33:27 -07:00
syscall.c get rid of union semop in sys_semctl(2) arguments 2013-03-05 15:14:16 -05:00
util.c ipc/util.c, ipc_rcu_alloc: cacheline align allocation 2013-07-09 10:33:28 -07:00
util.h ipc: close open coded spin lock calls 2013-07-09 10:33:27 -07:00