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Commit 5634cc2a authored by Tejun Heo's avatar Tejun Heo Committed by Jens Axboe
Browse files

writeback: update writeback tracepoints to report cgroup 



The following tracepoints are updated to report the cgroup used during
cgroup writeback.

* writeback_write_inode[_start]
* writeback_queue
* writeback_exec
* writeback_start
* writeback_written
* writeback_wait
* writeback_nowork
* writeback_wake_background
* wbc_writepage
* writeback_queue_io
* bdi_dirty_ratelimit
* balance_dirty_pages
* writeback_sb_inodes_requeue
* writeback_single_inode[_start]

Note that writeback_bdi_register is separated out from writeback_class
as reporting cgroup doesn't make sense to it.  Tracepoints which take
bdi are updated to take bdi_writeback instead.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Suggested-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 9acee9c5

fs/fs-writeback.c

+7 −7
Original line number Diff line number Diff line
@@ -176,7 +176,7 @@ static void wb_wakeup(struct bdi_writeback *wb) 
static void wb_queue_work(struct bdi_writeback *wb,

			  struct wb_writeback_work *work)

{

	trace_writeback_queue(wb->bdi, work);

	trace_writeback_queue(wb, work);



	spin_lock_bh(&wb->work_lock);

	if (!test_bit(WB_registered, &wb->state))
@@ -883,7 +883,7 @@ void wb_start_writeback(struct bdi_writeback *wb, long nr_pages, 
	 */

	work = kzalloc(sizeof(*work), GFP_ATOMIC);

	if (!work) {

		trace_writeback_nowork(wb->bdi);

		trace_writeback_nowork(wb);

		wb_wakeup(wb);

		return;

	}
@@ -913,7 +913,7 @@ void wb_start_background_writeback(struct bdi_writeback *wb) 
	 * We just wake up the flusher thread. It will perform background

	 * writeback as soon as there is no other work to do.

	 */

	trace_writeback_wake_background(wb->bdi);

	trace_writeback_wake_background(wb);

	wb_wakeup(wb);

}
@@ -1616,14 +1616,14 @@ static long wb_writeback(struct bdi_writeback *wb, 
		} else if (work->for_background)

			oldest_jif = jiffies;



		trace_writeback_start(wb->bdi, work);

		trace_writeback_start(wb, work);

		if (list_empty(&wb->b_io))

			queue_io(wb, work);

		if (work->sb)

			progress = writeback_sb_inodes(work->sb, wb, work);

		else

			progress = __writeback_inodes_wb(wb, work);

		trace_writeback_written(wb->bdi, work);

		trace_writeback_written(wb, work);



		wb_update_bandwidth(wb, wb_start);
@@ -1648,7 +1648,7 @@ static long wb_writeback(struct bdi_writeback *wb, 
		 * we'll just busyloop.

		 */

		if (!list_empty(&wb->b_more_io))  {

			trace_writeback_wait(wb->bdi, work);

			trace_writeback_wait(wb, work);

			inode = wb_inode(wb->b_more_io.prev);

			spin_lock(&inode->i_lock);

			spin_unlock(&wb->list_lock);
@@ -1754,7 +1754,7 @@ static long wb_do_writeback(struct bdi_writeback *wb) 
	while ((work = get_next_work_item(wb)) != NULL) {

		struct wb_completion *done = work->done;



		trace_writeback_exec(wb->bdi, work);

		trace_writeback_exec(wb, work);



		wrote += wb_writeback(wb, work);

include/trace/events/writeback.h

+141 −39
Original line number Diff line number Diff line
@@ -131,6 +131,66 @@ DEFINE_EVENT(writeback_dirty_inode_template, writeback_dirty_inode, 
	TP_ARGS(inode, flags)

);



#ifdef CREATE_TRACE_POINTS

#ifdef CONFIG_CGROUP_WRITEBACK



static inline size_t __trace_wb_cgroup_size(struct bdi_writeback *wb)

{

	return kernfs_path_len(wb->memcg_css->cgroup->kn) + 1;

}



static inline void __trace_wb_assign_cgroup(char *buf, struct bdi_writeback *wb)

{

	struct cgroup *cgrp = wb->memcg_css->cgroup;

	char *path;



	path = cgroup_path(cgrp, buf, kernfs_path_len(cgrp->kn) + 1);

	WARN_ON_ONCE(path != buf);

}



static inline size_t __trace_wbc_cgroup_size(struct writeback_control *wbc)

{

	if (wbc->wb)

		return __trace_wb_cgroup_size(wbc->wb);

	else

		return 2;

}



static inline void __trace_wbc_assign_cgroup(char *buf,

					     struct writeback_control *wbc)

{

	if (wbc->wb)

		__trace_wb_assign_cgroup(buf, wbc->wb);

	else

		strcpy(buf, "/");

}



#else	/* CONFIG_CGROUP_WRITEBACK */



static inline size_t __trace_wb_cgroup_size(struct bdi_writeback *wb)

{

	return 2;

}



static inline void __trace_wb_assign_cgroup(char *buf, struct bdi_writeback *wb)

{

	strcpy(buf, "/");

}



static inline size_t __trace_wbc_cgroup_size(struct writeback_control *wbc)

{

	return 2;

}



static inline void __trace_wbc_assign_cgroup(char *buf,

					     struct writeback_control *wbc)

{

	strcpy(buf, "/");

}



#endif	/* CONFIG_CGROUP_WRITEBACK */

#endif	/* CREATE_TRACE_POINTS */



DECLARE_EVENT_CLASS(writeback_write_inode_template,



	TP_PROTO(struct inode *inode, struct writeback_control *wbc),
@@ -141,6 +201,7 @@ DECLARE_EVENT_CLASS(writeback_write_inode_template, 
		__array(char, name, 32)

		__field(unsigned long, ino)

		__field(int, sync_mode)

		__dynamic_array(char, cgroup, __trace_wbc_cgroup_size(wbc))

	),



	TP_fast_assign(
@@ -148,12 +209,14 @@ DECLARE_EVENT_CLASS(writeback_write_inode_template, 
			dev_name(inode_to_bdi(inode)->dev), 32);

		__entry->ino		= inode->i_ino;

		__entry->sync_mode	= wbc->sync_mode;

		__trace_wbc_assign_cgroup(__get_str(cgroup), wbc);

	),



	TP_printk("bdi %s: ino=%lu sync_mode=%d",

	TP_printk("bdi %s: ino=%lu sync_mode=%d cgroup=%s",

		__entry->name,

		__entry->ino,

		__entry->sync_mode

		__entry->sync_mode,

		__get_str(cgroup)

	)

);
@@ -172,8 +235,8 @@ DEFINE_EVENT(writeback_write_inode_template, writeback_write_inode, 
);



DECLARE_EVENT_CLASS(writeback_work_class,

	TP_PROTO(struct backing_dev_info *bdi, struct wb_writeback_work *work),

	TP_ARGS(bdi, work),

	TP_PROTO(struct bdi_writeback *wb, struct wb_writeback_work *work),

	TP_ARGS(wb, work),

	TP_STRUCT__entry(

		__array(char, name, 32)

		__field(long, nr_pages)
@@ -183,10 +246,11 @@ DECLARE_EVENT_CLASS(writeback_work_class, 
		__field(int, range_cyclic)

		__field(int, for_background)

		__field(int, reason)

		__dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb))

	),

	TP_fast_assign(

		strncpy(__entry->name,

			bdi->dev ? dev_name(bdi->dev) : "(unknown)", 32);

			wb->bdi->dev ? dev_name(wb->bdi->dev) : "(unknown)", 32);

		__entry->nr_pages = work->nr_pages;

		__entry->sb_dev = work->sb ? work->sb->s_dev : 0;

		__entry->sync_mode = work->sync_mode;
@@ -194,9 +258,10 @@ DECLARE_EVENT_CLASS(writeback_work_class, 
		__entry->range_cyclic = work->range_cyclic;

		__entry->for_background	= work->for_background;

		__entry->reason = work->reason;

		__trace_wb_assign_cgroup(__get_str(cgroup), wb);

	),

	TP_printk("bdi %s: sb_dev %d:%d nr_pages=%ld sync_mode=%d "

		  "kupdate=%d range_cyclic=%d background=%d reason=%s",

		  "kupdate=%d range_cyclic=%d background=%d reason=%s cgroup=%s",

		  __entry->name,

		  MAJOR(__entry->sb_dev), MINOR(__entry->sb_dev),

		  __entry->nr_pages,
@@ -204,13 +269,14 @@ DECLARE_EVENT_CLASS(writeback_work_class, 
		  __entry->for_kupdate,

		  __entry->range_cyclic,

		  __entry->for_background,

		  __print_symbolic(__entry->reason, WB_WORK_REASON)

		  __print_symbolic(__entry->reason, WB_WORK_REASON),

		  __get_str(cgroup)

	)

);

#define DEFINE_WRITEBACK_WORK_EVENT(name) \

DEFINE_EVENT(writeback_work_class, name, \

	TP_PROTO(struct backing_dev_info *bdi, struct wb_writeback_work *work), \

	TP_ARGS(bdi, work))

	TP_PROTO(struct bdi_writeback *wb, struct wb_writeback_work *work), \

	TP_ARGS(wb, work))

DEFINE_WRITEBACK_WORK_EVENT(writeback_queue);

DEFINE_WRITEBACK_WORK_EVENT(writeback_exec);

DEFINE_WRITEBACK_WORK_EVENT(writeback_start);
@@ -230,26 +296,42 @@ TRACE_EVENT(writeback_pages_written, 
);



DECLARE_EVENT_CLASS(writeback_class,

	TP_PROTO(struct backing_dev_info *bdi),

	TP_ARGS(bdi),

	TP_PROTO(struct bdi_writeback *wb),

	TP_ARGS(wb),

	TP_STRUCT__entry(

		__array(char, name, 32)

		__dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb))

	),

	TP_fast_assign(

		strncpy(__entry->name, dev_name(bdi->dev), 32);

		strncpy(__entry->name, dev_name(wb->bdi->dev), 32);

		__trace_wb_assign_cgroup(__get_str(cgroup), wb);

	),

	TP_printk("bdi %s",

		  __entry->name

	TP_printk("bdi %s: cgroup=%s",

		  __entry->name,

		  __get_str(cgroup)

	)

);

#define DEFINE_WRITEBACK_EVENT(name) \

DEFINE_EVENT(writeback_class, name, \

	TP_PROTO(struct backing_dev_info *bdi), \

	TP_ARGS(bdi))

	TP_PROTO(struct bdi_writeback *wb), \

	TP_ARGS(wb))



DEFINE_WRITEBACK_EVENT(writeback_nowork);

DEFINE_WRITEBACK_EVENT(writeback_wake_background);

DEFINE_WRITEBACK_EVENT(writeback_bdi_register);



TRACE_EVENT(writeback_bdi_register,

	TP_PROTO(struct backing_dev_info *bdi),

	TP_ARGS(bdi),

	TP_STRUCT__entry(

		__array(char, name, 32)

	),

	TP_fast_assign(

		strncpy(__entry->name, dev_name(bdi->dev), 32);

	),

	TP_printk("bdi %s",

		__entry->name

	)

);



DECLARE_EVENT_CLASS(wbc_class,

	TP_PROTO(struct writeback_control *wbc, struct backing_dev_info *bdi),
@@ -265,6 +347,7 @@ DECLARE_EVENT_CLASS(wbc_class, 
		__field(int, range_cyclic)

		__field(long, range_start)

		__field(long, range_end)

		__dynamic_array(char, cgroup, __trace_wbc_cgroup_size(wbc))

	),



	TP_fast_assign(
@@ -278,11 +361,12 @@ DECLARE_EVENT_CLASS(wbc_class, 
		__entry->range_cyclic	= wbc->range_cyclic;

		__entry->range_start	= (long)wbc->range_start;

		__entry->range_end	= (long)wbc->range_end;

		__trace_wbc_assign_cgroup(__get_str(cgroup), wbc);

	),



	TP_printk("bdi %s: towrt=%ld skip=%ld mode=%d kupd=%d "

		"bgrd=%d reclm=%d cyclic=%d "

		"start=0x%lx end=0x%lx",

		"start=0x%lx end=0x%lx cgroup=%s",

		__entry->name,

		__entry->nr_to_write,

		__entry->pages_skipped,
@@ -292,7 +376,9 @@ DECLARE_EVENT_CLASS(wbc_class, 
		__entry->for_reclaim,

		__entry->range_cyclic,

		__entry->range_start,

		__entry->range_end)

		__entry->range_end,

		__get_str(cgroup)

	)

)



#define DEFINE_WBC_EVENT(name) \
@@ -312,6 +398,7 @@ TRACE_EVENT(writeback_queue_io, 
		__field(long,		age)

		__field(int,		moved)

		__field(int,		reason)

		__dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb))

	),

	TP_fast_assign(

		unsigned long *older_than_this = work->older_than_this;
@@ -321,13 +408,15 @@ TRACE_EVENT(writeback_queue_io, 
				  (jiffies - *older_than_this) * 1000 / HZ : -1;

		__entry->moved	= moved;

		__entry->reason	= work->reason;

		__trace_wb_assign_cgroup(__get_str(cgroup), wb);

	),

	TP_printk("bdi %s: older=%lu age=%ld enqueue=%d reason=%s",

	TP_printk("bdi %s: older=%lu age=%ld enqueue=%d reason=%s cgroup=%s",

		__entry->name,

		__entry->older,	/* older_than_this in jiffies */

		__entry->age,	/* older_than_this in relative milliseconds */

		__entry->moved,

		__print_symbolic(__entry->reason, WB_WORK_REASON)

		__print_symbolic(__entry->reason, WB_WORK_REASON),

		__get_str(cgroup)

	)

);
@@ -381,11 +470,11 @@ TRACE_EVENT(global_dirty_state, 


TRACE_EVENT(bdi_dirty_ratelimit,



	TP_PROTO(struct backing_dev_info *bdi,

	TP_PROTO(struct bdi_writeback *wb,

		 unsigned long dirty_rate,

		 unsigned long task_ratelimit),



	TP_ARGS(bdi, dirty_rate, task_ratelimit),

	TP_ARGS(wb, dirty_rate, task_ratelimit),



	TP_STRUCT__entry(

		__array(char,		bdi, 32)
@@ -395,36 +484,39 @@ TRACE_EVENT(bdi_dirty_ratelimit, 
		__field(unsigned long,	dirty_ratelimit)

		__field(unsigned long,	task_ratelimit)

		__field(unsigned long,	balanced_dirty_ratelimit)

		__dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb))

	),



	TP_fast_assign(

		strlcpy(__entry->bdi, dev_name(bdi->dev), 32);

		__entry->write_bw	= KBps(bdi->wb.write_bandwidth);

		__entry->avg_write_bw	= KBps(bdi->wb.avg_write_bandwidth);

		strlcpy(__entry->bdi, dev_name(wb->bdi->dev), 32);

		__entry->write_bw	= KBps(wb->write_bandwidth);

		__entry->avg_write_bw	= KBps(wb->avg_write_bandwidth);

		__entry->dirty_rate	= KBps(dirty_rate);

		__entry->dirty_ratelimit = KBps(bdi->wb.dirty_ratelimit);

		__entry->dirty_ratelimit = KBps(wb->dirty_ratelimit);

		__entry->task_ratelimit	= KBps(task_ratelimit);

		__entry->balanced_dirty_ratelimit =

					KBps(bdi->wb.balanced_dirty_ratelimit);

					KBps(wb->balanced_dirty_ratelimit);

		__trace_wb_assign_cgroup(__get_str(cgroup), wb);

	),



	TP_printk("bdi %s: "

		  "write_bw=%lu awrite_bw=%lu dirty_rate=%lu "

		  "dirty_ratelimit=%lu task_ratelimit=%lu "

		  "balanced_dirty_ratelimit=%lu",

		  "balanced_dirty_ratelimit=%lu cgroup=%s",

		  __entry->bdi,

		  __entry->write_bw,		/* write bandwidth */

		  __entry->avg_write_bw,	/* avg write bandwidth */

		  __entry->dirty_rate,		/* bdi dirty rate */

		  __entry->dirty_ratelimit,	/* base ratelimit */

		  __entry->task_ratelimit, /* ratelimit with position control */

		  __entry->balanced_dirty_ratelimit /* the balanced ratelimit */

		  __entry->balanced_dirty_ratelimit, /* the balanced ratelimit */

		  __get_str(cgroup)

	)

);



TRACE_EVENT(balance_dirty_pages,



	TP_PROTO(struct backing_dev_info *bdi,

	TP_PROTO(struct bdi_writeback *wb,

		 unsigned long thresh,

		 unsigned long bg_thresh,

		 unsigned long dirty,
@@ -437,7 +529,7 @@ TRACE_EVENT(balance_dirty_pages, 
		 long pause,

		 unsigned long start_time),



	TP_ARGS(bdi, thresh, bg_thresh, dirty, bdi_thresh, bdi_dirty,

	TP_ARGS(wb, thresh, bg_thresh, dirty, bdi_thresh, bdi_dirty,

		dirty_ratelimit, task_ratelimit,

		dirtied, period, pause, start_time),
@@ -456,11 +548,12 @@ TRACE_EVENT(balance_dirty_pages, 
		__field(	 long,	pause)

		__field(unsigned long,	period)

		__field(	 long,	think)

		__dynamic_array(char, cgroup, __trace_wb_cgroup_size(wb))

	),



	TP_fast_assign(

		unsigned long freerun = (thresh + bg_thresh) / 2;

		strlcpy(__entry->bdi, dev_name(bdi->dev), 32);

		strlcpy(__entry->bdi, dev_name(wb->bdi->dev), 32);



		__entry->limit		= global_wb_domain.dirty_limit;

		__entry->setpoint	= (global_wb_domain.dirty_limit +
@@ -478,6 +571,7 @@ TRACE_EVENT(balance_dirty_pages, 
		__entry->period		= period * 1000 / HZ;

		__entry->pause		= pause * 1000 / HZ;

		__entry->paused		= (jiffies - start_time) * 1000 / HZ;

		__trace_wb_assign_cgroup(__get_str(cgroup), wb);

	),
@@ -486,7 +580,7 @@ TRACE_EVENT(balance_dirty_pages, 
		  "bdi_setpoint=%lu bdi_dirty=%lu "

		  "dirty_ratelimit=%lu task_ratelimit=%lu "

		  "dirtied=%u dirtied_pause=%u "

		  "paused=%lu pause=%ld period=%lu think=%ld",

		  "paused=%lu pause=%ld period=%lu think=%ld cgroup=%s",

		  __entry->bdi,

		  __entry->limit,

		  __entry->setpoint,
@@ -500,7 +594,8 @@ TRACE_EVENT(balance_dirty_pages, 
		  __entry->paused,	/* ms */

		  __entry->pause,	/* ms */

		  __entry->period,	/* ms */

		  __entry->think	/* ms */

		  __entry->think,	/* ms */

		  __get_str(cgroup)

	  )

);
@@ -514,6 +609,8 @@ TRACE_EVENT(writeback_sb_inodes_requeue, 
		__field(unsigned long, ino)

		__field(unsigned long, state)

		__field(unsigned long, dirtied_when)

		__dynamic_array(char, cgroup,

				__trace_wb_cgroup_size(inode_to_wb(inode)))

	),



	TP_fast_assign(
@@ -522,14 +619,16 @@ TRACE_EVENT(writeback_sb_inodes_requeue, 
		__entry->ino		= inode->i_ino;

		__entry->state		= inode->i_state;

		__entry->dirtied_when	= inode->dirtied_when;

		__trace_wb_assign_cgroup(__get_str(cgroup), inode_to_wb(inode));

	),



	TP_printk("bdi %s: ino=%lu state=%s dirtied_when=%lu age=%lu",

	TP_printk("bdi %s: ino=%lu state=%s dirtied_when=%lu age=%lu cgroup=%s",

		  __entry->name,

		  __entry->ino,

		  show_inode_state(__entry->state),

		  __entry->dirtied_when,

		  (jiffies - __entry->dirtied_when) / HZ

		  (jiffies - __entry->dirtied_when) / HZ,

		  __get_str(cgroup)

	)

);
@@ -585,6 +684,7 @@ DECLARE_EVENT_CLASS(writeback_single_inode_template, 
		__field(unsigned long, writeback_index)

		__field(long, nr_to_write)

		__field(unsigned long, wrote)

		__dynamic_array(char, cgroup, __trace_wbc_cgroup_size(wbc))

	),



	TP_fast_assign(
@@ -596,10 +696,11 @@ DECLARE_EVENT_CLASS(writeback_single_inode_template, 
		__entry->writeback_index = inode->i_mapping->writeback_index;

		__entry->nr_to_write	= nr_to_write;

		__entry->wrote		= nr_to_write - wbc->nr_to_write;

		__trace_wbc_assign_cgroup(__get_str(cgroup), wbc);

	),



	TP_printk("bdi %s: ino=%lu state=%s dirtied_when=%lu age=%lu "

		  "index=%lu to_write=%ld wrote=%lu",

		  "index=%lu to_write=%ld wrote=%lu cgroup=%s",

		  __entry->name,

		  __entry->ino,

		  show_inode_state(__entry->state),
@@ -607,7 +708,8 @@ DECLARE_EVENT_CLASS(writeback_single_inode_template, 
		  (jiffies - __entry->dirtied_when) / HZ,

		  __entry->writeback_index,

		  __entry->nr_to_write,

		  __entry->wrote

		  __entry->wrote,

		  __get_str(cgroup)

	)

);

mm/page-writeback.c

+3 −3
Original line number Diff line number Diff line
@@ -1289,7 +1289,7 @@ static void wb_update_dirty_ratelimit(struct dirty_throttle_control *dtc, 
	wb->dirty_ratelimit = max(dirty_ratelimit, 1UL);

	wb->balanced_dirty_ratelimit = balanced_dirty_ratelimit;



	trace_bdi_dirty_ratelimit(wb->bdi, dirty_rate, task_ratelimit);

	trace_bdi_dirty_ratelimit(wb, dirty_rate, task_ratelimit);

}



static void __wb_update_bandwidth(struct dirty_throttle_control *gdtc,
@@ -1683,7 +1683,7 @@ static void balance_dirty_pages(struct address_space *mapping, 
		 * do a reset, as it may be a light dirtier.

		 */

		if (pause < min_pause) {

			trace_balance_dirty_pages(bdi,

			trace_balance_dirty_pages(wb,

						  sdtc->thresh,

						  sdtc->bg_thresh,

						  sdtc->dirty,
@@ -1712,7 +1712,7 @@ static void balance_dirty_pages(struct address_space *mapping, 
		}



pause:

		trace_balance_dirty_pages(bdi,

		trace_balance_dirty_pages(wb,

					  sdtc->thresh,

					  sdtc->bg_thresh,

					  sdtc->dirty,