kernel_optimize_test/ipc
Davidlohr Bueso e3658538bf ipc/msg: batch queue sender wakeups
Currently the use of wake_qs in sysv msg queues are only for the receiver
tasks that are blocked on the queue.  But blocked sender tasks (due to
queue size constraints) still are awoken with the ipc object lock held,
which can be a problem particularly for small sized queues and far from
gracious for -rt (just like it was for the receiver side).

The paths that actually wakeup a sender are obviously related to when we
are either getting rid of the queue or after (some) space is freed-up
after a receiver takes the msg (msgrcv).  Furthermore, with the exception
of msgrcv, we can always piggy-back on expunge_all that has its own tasks
lined-up for waking.  Finally, upon unlinking the message, it should be no
problem delaying the wakeups a bit until after we've released the lock.

Link: http://lkml.kernel.org/r/1469748819-19484-3-git-send-email-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:33 -07:00
..
compat_mq.c
compat.c
ipc_sysctl.c
Makefile
mq_sysctl.c
mqueue.c fs: Replace CURRENT_TIME with current_time() for inode timestamps 2016-09-27 21:06:21 -04:00
msg.c ipc/msg: batch queue sender wakeups 2016-10-11 15:06:33 -07:00
msgutil.c ipc: delete "nr_ipc_ns" 2016-08-02 19:35:44 -04:00
namespace.c Merge branch 'nsfs-ioctls' into HEAD 2016-09-22 20:00:36 -05:00
sem.c ipc/sem.c: fix complex_count vs. simple op race 2016-10-11 15:06:33 -07:00
shm.c shmem: make shmem_inode_info::lock irq-safe 2016-07-26 16:19:19 -07:00
syscall.c
util.c tree wide: use kvfree() than conditional kfree()/vfree() 2016-01-22 17:02:18 -08:00
util.h tree wide: use kvfree() than conditional kfree()/vfree() 2016-01-22 17:02:18 -08:00