From: Artem Bityutskiy <dedekind1@gmail.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [RFC][PATCH 09/16] writeback: do not lose wake-ups in bdi threads
Date: Fri, 16 Jul 2010 15:45:05 +0300 [thread overview]
Message-ID: <1279284312-2411-10-git-send-email-dedekind1@gmail.com> (raw)
In-Reply-To: <1279284312-2411-1-git-send-email-dedekind1@gmail.com>
From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
The bdi threads ('bdi_writeback_thread()') can lose wake-ups if,
for example, 'bdi_queue_work()' is executed while after the bdi
thread finished 'wb_do_writeback()' but before it has called
'schedule_timeout_interruptible()'.
To fix this issue, we have to check whether we have works to
process after we change the task state to 'TASK_INTERRUPTIBLE'.
Also, 'bdi_writeback_thread()' inconsistently handles the cases
when 'dirty_writeback_interval' is zero and non-zero. But there is
no fundamental difference between these cases, so they have to be
handled the same way, which this patch also does.
This patch also removes strange 'list_empty_careful()' call.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
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 3fc5194..f045450 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:[~2010-07-16 12:45 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-16 12:44 [RFC][PATCH 00/16] kill unnecessary bdi wakeups + cleanups Artem Bityutskiy
2010-07-16 12:44 ` [RFC][PATCH 01/16] writeback: do not self-wakeup Artem Bityutskiy
2010-07-18 6:44 ` Christoph Hellwig
2010-07-18 9:43 ` Artem Bityutskiy
2010-07-16 12:44 ` [RFC][PATCH 02/16] writeback: remove redundant list initialization Artem Bityutskiy
2010-07-18 6:44 ` Christoph Hellwig
2010-07-16 12:44 ` [RFC][PATCH 03/16] writeback: harmonize writeback threads naming Artem Bityutskiy
2010-07-18 6:45 ` Christoph Hellwig
2010-07-16 12:45 ` [RFC][PATCH 04/16] writeback: fix possible race when shutting down bdi Artem Bityutskiy
2010-07-18 6:47 ` Christoph Hellwig
2010-07-20 8:58 ` Artem Bityutskiy
2010-07-16 12:45 ` [RFC][PATCH 05/16] writeback: fix possible race when creating bdi threads Artem Bityutskiy
2010-07-16 12:45 ` [RFC][PATCH 06/16] writeback: improve bdi_has_dirty_io Artem Bityutskiy
2010-07-18 6:49 ` Christoph Hellwig
2010-07-16 12:45 ` [RFC][PATCH 07/16] writeback: do not lose wake-ups in the forker thread Artem Bityutskiy
2010-07-18 6:49 ` Christoph Hellwig
2010-07-16 12:45 ` [RFC][PATCH 08/16] writeback: do not lose default bdi wake-ups Artem Bityutskiy
2010-07-18 6:52 ` Christoph Hellwig
2010-07-16 12:45 ` Artem Bityutskiy [this message]
2010-07-18 6:52 ` [RFC][PATCH 09/16] writeback: do not lose wake-ups in bdi threads Christoph Hellwig
2010-07-16 12:45 ` [RFC][PATCH 10/16] writeback: simplify bdi code a little Artem Bityutskiy
2010-07-18 6:56 ` Christoph Hellwig
2010-07-20 10:34 ` Artem Bityutskiy
2010-07-16 12:45 ` [RFC][PATCH 11/16] writeback: move last_active to bdi Artem Bityutskiy
2010-07-18 7:03 ` Christoph Hellwig
2010-07-16 12:45 ` [RFC][PATCH 12/16] writeback: add to bdi_list in the forker thread Artem Bityutskiy
2010-07-18 6:58 ` Christoph Hellwig
2010-07-20 11:07 ` Artem Bityutskiy
2010-07-20 11:32 ` Artem Bityutskiy
2010-07-16 12:45 ` [RFC][PATCH 13/16] writeback: restructure bdi forker loop a little Artem Bityutskiy
2010-07-16 12:45 ` [RFC][PATCH 14/16] writeback: move bdi threads exiting logic to the forker thread Artem Bityutskiy
2010-07-18 7:02 ` Christoph Hellwig
2010-07-20 12:23 ` Artem Bityutskiy
2010-07-20 12:54 ` Artem Bityutskiy
2010-07-16 12:45 ` [RFC][PATCH 15/16] writeback: clean-up the warning about non-registered bdi Artem Bityutskiy
2010-07-18 7:03 ` Christoph Hellwig
2010-07-16 12:45 ` [RFC][PATCH 16/16] writeback: prevent unnecessary bdi threads wakeups Artem Bityutskiy
2010-07-18 7:45 ` Christoph Hellwig
2010-07-20 13:13 ` Artem Bityutskiy
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