From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: [patch RT 6/7] fs, jbd: pull your plug when waiting for space Date: Wed, 11 Jul 2012 22:05:20 -0000 Message-ID: <20120711215612.161878327@linutronix.de> References: <20120711214552.036760674@linutronix.de> Cc: Steven Rostedt , RT-users , Carsten Emde , Mike Galbraith , Theodore Tso To: LKML Return-path: Content-Disposition: inline; filename=fs-jbd-pull-plug-when-waiting.patch Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org With an -rt kernel, and a heavy sync IO load, tasks can jam up on journal locks without unplugging, which can lead to terminal IO starvation. Unplug and schedule when waiting for space. Signed-off-by: Mike Galbraith Cc: Steven Rostedt Cc: Theodore Tso Link: http://lkml.kernel.org/r/1341812414.7370.73.camel@marge.simpson.net Signed-off-by: Thomas Gleixner --- fs/jbd/checkpoint.c | 2 ++ 1 file changed, 2 insertions(+) Index: linux-stable-rt/fs/jbd/checkpoint.c =================================================================== --- linux-stable-rt.orig/fs/jbd/checkpoint.c +++ linux-stable-rt/fs/jbd/checkpoint.c @@ -129,6 +129,8 @@ void __log_wait_for_space(journal_t *jou if (journal->j_flags & JFS_ABORT) return; spin_unlock(&journal->j_state_lock); + if (current->plug) + io_schedule(); mutex_lock(&journal->j_checkpoint_mutex); /*