]> git.baikalelectronics.ru Git - kernel.git/commit
mqueue: separate mqueue default value from maximum value
authorKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Thu, 31 May 2012 23:26:33 +0000 (16:26 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 1 Jun 2012 00:49:31 +0000 (17:49 -0700)
commitc45383df6820ee5ee90f53baac0b196d34bf9ac5
tree752c4116e0f93328239db9ff2c2ed730fef3ce0e
parente452700ebd7ba271a1ce0481f91bf283d80ae7ee
mqueue: separate mqueue default value from maximum value

Commit 40f61d147e18 ("message queues: increase range limits") changed
mqueue default value when attr parameter is specified NULL from hard
coded value to fs.mqueue.{msg,msgsize}_max sysctl value.

This made large side effect.  When user need to use two mqueue
applications 1) using !NULL attr parameter and it require big message
size and 2) using NULL attr parameter and only need small size message,
app (1) require to raise fs.mqueue.msgsize_max and app (2) consume large
memory size even though it doesn't need.

Doug Ledford propsed to switch back it to static hard coded value.
However it also has a compatibility problem.  Some applications might
started depend on the default value is tunable.

The solution is to separate default value from maximum value.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Acked-by: Joe Korty <joe.korty@ccur.com>
Cc: Amerigo Wang <amwang@redhat.com>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/sysctl/fs.txt
include/linux/ipc_namespace.h
ipc/mq_sysctl.c
ipc/mqueue.c