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| author | Vivek Goyal <vgoyal@redhat.com> | 2011-03-01 13:40:54 -0500 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2011-03-01 13:41:53 -0500 |
| commit | 450adcbe518ab3a3953d8475309525d22de77cba (patch) | |
| tree | 352fd47d75b86804e590fd88c09f953a798ba8b0 /include | |
| parent | 3e1f2356ce231488dc1fa844e5ce91bcb59fc2a1 (diff) | |
| download | lwn-450adcbe518ab3a3953d8475309525d22de77cba.tar.gz lwn-450adcbe518ab3a3953d8475309525d22de77cba.zip | |
blk-throttle: Do not use kblockd workqueue for throtl work
o Dominik Klein reported a system hang issue while doing some blkio
throttling testing.
https://lkml.org/lkml/2011/2/24/173
o Some tracing revealed that CFQ was not dispatching any more jobs as
queue unplug was not happening. And queue unplug was not happening
because unplug work was not being called as there was one throttling
work on same cpu which as not finished yet. And throttling work had not
finished as it was tyring to dispatch a bio to CFQ but all the request
descriptors were consume to it was put to sleep.
o So basically it is a cyclic dependecny between CFQ unplug work and
throtl dispatch work. Tejun suggested that use separate workqueue for
such cases.
o This patch uses a separate workqueue for throttle related work and
does not rely on kblockd workqueue anymore.
Cc: stable@kernel.org
Reported-by: Dominik Klein <dk@in-telegence.net>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/blkdev.h | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 4d18ff34670a..dd8cd0f47e3a 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1088,7 +1088,6 @@ static inline void put_dev_sector(Sector p) struct work_struct; int kblockd_schedule_work(struct request_queue *q, struct work_struct *work); -int kblockd_schedule_delayed_work(struct request_queue *q, struct delayed_work *dwork, unsigned long delay); #ifdef CONFIG_BLK_CGROUP /* @@ -1136,7 +1135,6 @@ static inline uint64_t rq_io_start_time_ns(struct request *req) extern int blk_throtl_init(struct request_queue *q); extern void blk_throtl_exit(struct request_queue *q); extern int blk_throtl_bio(struct request_queue *q, struct bio **bio); -extern void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay); extern void throtl_shutdown_timer_wq(struct request_queue *q); #else /* CONFIG_BLK_DEV_THROTTLING */ static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio) @@ -1146,7 +1144,6 @@ static inline int blk_throtl_bio(struct request_queue *q, struct bio **bio) static inline int blk_throtl_init(struct request_queue *q) { return 0; } static inline int blk_throtl_exit(struct request_queue *q) { return 0; } -static inline void throtl_schedule_delayed_work(struct request_queue *q, unsigned long delay) {} static inline void throtl_shutdown_timer_wq(struct request_queue *q) {} #endif /* CONFIG_BLK_DEV_THROTTLING */ |