From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx176.postini.com [74.125.245.176]) by kanga.kvack.org (Postfix) with SMTP id CEEB76B0074 for ; Sun, 19 May 2013 16:08:09 -0400 (EDT) From: Glauber Costa Subject: [PATCH v7 20/34] i915: bail out earlier when shrinker cannot acquire mutex Date: Mon, 20 May 2013 00:07:13 +0400 Message-Id: <1368994047-5997-21-git-send-email-glommer@openvz.org> In-Reply-To: <1368994047-5997-1-git-send-email-glommer@openvz.org> References: <1368994047-5997-1-git-send-email-glommer@openvz.org> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: cgroups@vger.kernel.org, Andrew Morton , Greg Thelen , kamezawa.hiroyu@jp.fujitsu.com, Michal Hocko , Johannes Weiner , linux-fsdevel@vger.kernel.org, Dave Chinner , hughd@google.com, Glauber Costa , Dave Chinner , Mel Gorman , Daniel Vetter , Kent Overstreet The main shrinker driver will keep trying for a while to free objects if the returned value from the shrink scan procedure is 0. That means "no objects now", but a retry could very well succeed. A negative value has a different meaning. It means it is impossible to shrink, and we would better bail out soon. We find this behavior more appropriate for the case where the lock cannot be taken. Specially given the hammer behavior of the i915: if another thread is already shrinking, we are likely not to be able to shrink anything anyway when we finally acquire the mutex. Signed-off-by: Glauber Costa CC: Dave Chinner CC: Mel Gorman CC: Daniel Vetter CC: Kent Overstreet --- drivers/gpu/drm/i915/i915_gem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 6b17122..52b3ac1 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -4448,10 +4448,10 @@ i915_gem_inactive_count(struct shrinker *shrinker, struct shrink_control *sc) if (!mutex_trylock(&dev->struct_mutex)) { if (!mutex_is_locked_by(&dev->struct_mutex, current)) - return 0; + return -1; if (dev_priv->mm.shrinker_no_lock_stealing) - return 0; + return -1; unlock = false; } -- 1.8.1.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org