Commit fd1f87d2 authored May 31, 2012 by KOSAKI Motohiro Committed by Linus Torvalds May 31, 2012

mqueue: don't use kmalloc with KMALLOC_MAX_SIZE



KMALLOC_MAX_SIZE is not a good threshold.  It is extremely high and
problematic.  Unfortunately, some silly drivers depend on this and we
can't change it.  But any new code needn't use such extreme ugly high
order allocations.  It brings us awful fragmentation issues and system
slowdown.

Signed-off-by: KOSAKI Motohiro <mkosaki@jp.fujitsu.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Acked-by: Joe Korty <joe.korty@ccur.com>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Joe Korty <joe.korty@ccur.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e6315bb1

ipc/mqueue.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -153,7 +153,7 @@ static struct inode mqueue_get_inode(struct super_block sb,
		info->attr.mq_msgsize = attr->mq_msgsize;
		}
		mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *);
		if (mq_msg_tblsz > KMALLOC_MAX_SIZE)
		if (mq_msg_tblsz > PAGE_SIZE)
		info->messages = vmalloc(mq_msg_tblsz);
		else
		info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
		@@ -266,7 +266,7 @@ static void mqueue_evict_inode(struct inode *inode)
		spin_lock(&info->lock);
		for (i = 0; i < info->attr.mq_curmsgs; i++)
		free_msg(info->messages[i]);
		if (info->attr.mq_maxmsg * sizeof(struct msg_msg *) > KMALLOC_MAX_SIZE)
		if (is_vmalloc_addr(info->messages))
		vfree(info->messages);
		else
		kfree(info->messages);