Centos-kernel-stream-9/ipc
Davidlohr Bueso ff35e5ef86 ipc,msg: provide barrier pairings for lockless receive
We currently use a full barrier on the sender side to to avoid receiver
tasks disappearing on us while still performing on the sender side wakeup.
 We lack however, the proper CPU-CPU interactions pairing on the receiver
side which busy-waits for the message.  Similarly, we do not need a full
smp_mb, and can relax the semantics for the writer and reader sides of the
message.  This is safe as we are only ordering loads and stores to r_msg.
And in both smp_wmb and smp_rmb, there are no stores after the calls
_anyway_.

This obviously applies for pipelined_send and expunge_all, for EIRDM when
destroying a queue.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30 19:44:58 -07:00
..
Makefile
compat.c
compat_mq.c
ipc_sysctl.c
mq_sysctl.c
mqueue.c
msg.c ipc,msg: provide barrier pairings for lockless receive 2015-06-30 19:44:58 -07:00
msgutil.c
namespace.c
sem.c
shm.c
syscall.c
util.c
util.h