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>

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 6f379c20b3e27adfd9c08301a98a4a94acc70932..6b67122d887bd5f63970666373d96a12a8420754 100644 (file)
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -151,7 +151,7 @@ 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);
@@ -264,7 +264,7 @@ 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);