[3.16.y-ckt stable] Patch "libceph: ceph-msgr workqueue needs a resque worker" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    libceph: ceph-msgr workqueue needs a resque worker

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt2.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 427ee2fadbd2d6da087c6a03bd5c45e89ae76035 Mon Sep 17 00:00:00 2001
From: Ilya Dryomov <idryomov at redhat.com>
Date: Fri, 10 Oct 2014 16:39:05 +0400
Subject: libceph: ceph-msgr workqueue needs a resque worker

commit f9865f06f7f18c6661c88d0511f05c48612319cc upstream.

Commit f363e45fd118 ("net/ceph: make ceph_msgr_wq non-reentrant")
effectively removed WQ_MEM_RECLAIM flag from ceph_msgr_wq.  This is
wrong - libceph is very much a memory reclaim path, so restore it.

Signed-off-by: Ilya Dryomov <idryomov at redhat.com>
Tested-by: Micha Krause <micha at krausam.de>
Reviewed-by: Sage Weil <sage at redhat.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/ceph/messenger.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 3d9ddc2842e1..6b15183a68c8 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -291,7 +291,11 @@ int ceph_msgr_init(void)
 	if (ceph_msgr_slab_init())
 		return -ENOMEM;

-	ceph_msgr_wq = alloc_workqueue("ceph-msgr", 0, 0);
+	/*
+	 * The number of active work items is limited by the number of
+	 * connections, so leave @max_active at default.
+	 */
+	ceph_msgr_wq = alloc_workqueue("ceph-msgr", WQ_MEM_RECLAIM, 0);
 	if (ceph_msgr_wq)
 		return 0;

--
2.1.0