path: root/ipc/mqueue.c
diff options
authorKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>2012-05-31 16:26:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-31 17:49:31 -0700
commitcef0184c115e5e4e10498f6548d9526465e72478 (patch)
tree752c4116e0f93328239db9ff2c2ed730fef3ce0e /ipc/mqueue.c
parentfd1f87d24d492fda464bedf10a5dd5174ff9b065 (diff)
mqueue: separate mqueue default value from maximum value
Commit b231cca4381e ("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>
Diffstat (limited to 'ipc/mqueue.c')
1 files changed, 6 insertions, 3 deletions
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 6828e2c93cef..609d53f7a915 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -145,9 +145,10 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
info->qsize = 0;
info->user = NULL; /* set when all is ok */
memset(&info->attr, 0, sizeof(info->attr));
- info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max, DFLT_MSG);
- info->attr.mq_msgsize =
- min(ipc_ns->mq_msgsize_max, DFLT_MSGSIZE);
+ info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max,
+ ipc_ns->mq_msg_default);
+ info->attr.mq_msgsize = min(ipc_ns->mq_msgsize_max,
+ ipc_ns->mq_msgsize_default);
if (attr) {
info->attr.mq_maxmsg = attr->mq_maxmsg;
info->attr.mq_msgsize = attr->mq_msgsize;
@@ -1261,6 +1262,8 @@ int mq_init_ns(struct ipc_namespace *ns)
ns->mq_queues_max = DFLT_QUEUESMAX;
ns->mq_msg_max = DFLT_MSGMAX;
ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
+ ns->mq_msg_default = DFLT_MSG;
+ ns->mq_msgsize_default = DFLT_MSGSIZE;
ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
if (IS_ERR(ns->mq_mnt)) {