From: Artem Bityutskiy <dedekind1@gmail.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCHv4 05/14] writeback: do not lose wake-ups in bdi threads
Date: Fri, 23 Jul 2010 18:05:45 +0300 [thread overview]
Message-ID: <1279897554-1526-6-git-send-email-dedekind1@gmail.com> (raw)
In-Reply-To: <1279897554-1526-1-git-send-email-dedekind1@gmail.com>
From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Currently, bdi threads ('bdi_writeback_thread()') can lose wake-ups. For
example, if 'bdi_queue_work()' is executed after the bdi thread have had
finished 'wb_do_writeback()' but before it called
'schedule_timeout_interruptible()'.
To fix this issue, we have to check whether we have works to process after we
have changed the task state to 'TASK_INTERRUPTIBLE'.
This patch also clean-ups handling of the cases when 'dirty_writeback_interval'
is zero or non-zero.
Additionally, this patch also removes unneeded 'list_empty_careful()' call.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
fs/fs-writeback.c | 17 +++++++++--------
1 files changed, 9 insertions(+), 8 deletions(-)
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 5e6b7fc..8cf53ba 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -848,17 +848,18 @@ int bdi_writeback_thread(void *data)
break;
}
- if (dirty_writeback_interval) {
- wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10);
- schedule_timeout_interruptible(wait_jiffies);
- } else {
- set_current_state(TASK_INTERRUPTIBLE);
- if (list_empty_careful(&wb->bdi->work_list) &&
- !kthread_should_stop())
- schedule();
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (!list_empty(&bdi->work_list)) {
__set_current_state(TASK_RUNNING);
+ continue;
}
+ if (dirty_writeback_interval) {
+ wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10);
+ schedule_timeout(wait_jiffies);
+ } else
+ schedule();
+
try_to_freeze();
}
--
1.7.1.1
next prev parent reply other threads:[~2010-07-23 15:05 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-23 15:05 [PATCHv4 00/14] kill unnecessary bdi wakeups + cleanups Artem Bityutskiy
2010-07-23 15:05 ` [PATCHv4 01/14] writeback: harmonize writeback threads naming Artem Bityutskiy
2010-07-23 15:05 ` [PATCHv4 02/14] writeback: fix possible race when creating bdi threads Artem Bityutskiy
2010-07-23 15:05 ` [PATCHv4 03/14] writeback: do not lose wake-ups in the forker thread - 1 Artem Bityutskiy
2010-07-23 15:05 ` [PATCHv4 04/14] writeback: do not lose wake-ups in the forker thread - 2 Artem Bityutskiy
2010-07-23 15:05 ` Artem Bityutskiy [this message]
2010-07-23 15:05 ` [PATCHv4 06/14] writeback: simplify bdi code a little Artem Bityutskiy
2010-07-23 15:05 ` [PATCHv4 07/14] writeback: do not remove bdi from bdi_list Artem Bityutskiy
2010-07-23 15:05 ` [PATCHv4 08/14] writeback: move last_active to bdi Artem Bityutskiy
2010-07-23 15:05 ` [PATCHv4 09/14] writeback: restructure bdi forker loop a little Artem Bityutskiy
2010-07-23 15:05 ` [PATCHv4 10/14] writeback: move bdi threads exiting logic to the forker thread Artem Bityutskiy
2010-07-23 16:23 ` Christoph Hellwig
2010-07-24 5:55 ` Artem Bityutskiy
2010-07-23 15:05 ` [PATCHv4 11/14] writeback: prevent unnecessary bdi threads wakeups Artem Bityutskiy
2010-07-23 15:05 ` [PATCHv4 12/14] writeback: optimize periodic bdi thread wakeups Artem Bityutskiy
2010-07-23 16:28 ` Christoph Hellwig
2010-07-24 6:00 ` Artem Bityutskiy
2010-07-23 15:05 ` [PATCHv4 13/14] writeback: remove unnecessary init_timer call Artem Bityutskiy
2010-07-23 16:28 ` Christoph Hellwig
2010-07-23 15:05 ` [PATCHv4 14/14] writeback: add new tracepoints Artem Bityutskiy
2010-07-23 16:29 ` Christoph Hellwig
2010-07-24 6:01 ` Artem Bityutskiy
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