Commit b4304a87 authored Jan 19, 2016 by Tim Murray Committed by Mark Salyzyn Feb 22, 2016

ANDROID: dm-verity: run in a WQ_HIGHPRI workqueue



(cherry picked from commit a96fcc535ba881b4100eb2c9db8423fe7ef23422)

Running dm-verity in a standard workqueue results in IO competing for
CPU time with standard user apps, which can lead to pipeline bubbles and
seriously degraded performance. Move to a WQ_HIGHPRI workqueue to
protect against that.

Signed-off-by: Tim Murray <timmurray@google.com>
Bug: 25392275
Change-Id: Ic65d7bd6f04e4d77780119e926a50e71323575f0

parent dcdee0d4

drivers/md/dm-verity-target.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -1046,7 +1046,9 @@ static int verity_ctr(struct dm_target ti, unsigned argc, char *argv)
		}

		/* WQ_UNBOUND greatly improves performance when running on ramdisk */
		v->verify_wq = alloc_workqueue("kverityd", WQ_CPU_INTENSIVE \| WQ_MEM_RECLAIM \| WQ_UNBOUND, num_online_cpus());
		v->verify_wq = alloc_workqueue("kverityd",
		WQ_HIGHPRI \| WQ_MEM_RECLAIM \| WQ_UNBOUND,
		num_online_cpus());
		if (!v->verify_wq) {
		ti->error = "Cannot allocate workqueue";
		r = -ENOMEM;