From 450adcbe518ab3a3953d8475309525d22de77cba Mon Sep 17 00:00:00 2001
From: Vivek Goyal <vgoyal@redhat.com>
Date: Tue, 1 Mar 2011 13:40:54 -0500
Subject: 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>
---
include/linux/blkdev.h | 3 ---
1 file changed, 3 deletions(-)
(limited to 'include/linux')
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 4d18ff3..dd8cd0f 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 */
--
cgit v1.1
From 1654e7411a1ad4999fe7890ef51d2a2bbb1fcf76 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Wed, 2 Mar 2011 08:48:05 -0500
Subject: block: add @force_kblockd to __blk_run_queue()
__blk_run_queue() automatically either calls q->request_fn() directly
or schedules kblockd depending on whether the function is recursed.
blk-flush implementation needs to be able to explicitly choose
kblockd. Add @force_kblockd.
All the current users are converted to specify %false for the
parameter and this patch doesn't introduce any behavior change.
stable: This is prerequisite for fixing ide oops caused by the new
blk-flush implementation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
---
include/linux/blkdev.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
(limited to 'include/linux')
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index dd8cd0f..d5063e1 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -699,7 +699,7 @@ extern void blk_start_queue(struct request_queue *q);
extern void blk_stop_queue(struct request_queue *q);
extern void blk_sync_queue(struct request_queue *q);
extern void __blk_stop_queue(struct request_queue *q);
-extern void __blk_run_queue(struct request_queue *);
+extern void __blk_run_queue(struct request_queue *q, bool force_kblockd);
extern void blk_run_queue(struct request_queue *);
extern int blk_rq_map_user(struct request_queue *, struct request *,
struct rq_map_data *, void __user *, unsigned long,
--
cgit v1.1
From 2d3a8497f8cc5aca14b722cd37d51f6c15ff9f74 Mon Sep 17 00:00:00 2001
From: Tao Ma <boyu.mt@taobao.com>
Date: Thu, 3 Mar 2011 10:53:20 -0500
Subject: blktrace: Remove blk_fill_rwbs_rq.
If we enable trace events to trace block actions, We use
blk_fill_rwbs_rq to analyze the corresponding actions
in request's cmd_flags, but we only choose the minor 2 bits
from it, so most of other flags(e.g, REQ_SYNC) are missing.
For example, with a sync write we get:
write_test-2409 [001] 160.013869: block_rq_insert: 3,64 W 0 () 258135 + =
8 [write_test]
Since now we have integrated the flags of both bio and request,
it is safe to pass rq->cmd_flags directly to blk_fill_rwbs and
blk_fill_rwbs_rq isn't needed any more.
With this patch, after a sync write we get:
write_test-2417 [000] 226.603878: block_rq_insert: 3,64 WS 0 () 258135 +=
8 [write_test]
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
---
include/linux/blktrace_api.h | 1 -
1 file changed, 1 deletion(-)
(limited to 'include/linux')
diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index 3395cf7..b22fb0d 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -245,7 +245,6 @@ static inline int blk_cmd_buf_len(struct request *rq)
extern void blk_dump_cmd(char *buf, struct request *rq);
extern void blk_fill_rwbs(char *rwbs, u32 rw, int bytes);
-extern void blk_fill_rwbs_rq(char *rwbs, struct request *rq);
#endif /* CONFIG_EVENT_TRACING && CONFIG_BLOCK */
--
cgit v1.1