From: Mel Gorman <mel@csn.ul.ie> To: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Linux Kernel List <linux-kernel@vger.kernel.org>, Johannes Weiner <hannes@cmpxchg.org>, Minchan Kim <minchan.kim@gmail.com>, Wu Fengguang <fengguang.wu@intel.com>, KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>, KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>, Mel Gorman <mel@csn.ul.ie> Subject: [PATCH 2/8] writeback: Account for time spent congestion_waited Date: Wed, 15 Sep 2010 13:27:45 +0100 [thread overview] Message-ID: <1284553671-31574-3-git-send-email-mel@csn.ul.ie> (raw) In-Reply-To: <1284553671-31574-1-git-send-email-mel@csn.ul.ie> There is strong evidence to indicate a lot of time is being spent in congestion_wait(), some of it unnecessarily. This patch adds a tracepoint for congestion_wait to record when congestion_wait() was called, how long the timeout was for and how long it actually slept. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> --- include/trace/events/writeback.h | 28 ++++++++++++++++++++++++++++ mm/backing-dev.c | 5 +++++ 2 files changed, 33 insertions(+), 0 deletions(-) diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index f345f66..275d477 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -153,6 +153,34 @@ DEFINE_WBC_EVENT(wbc_balance_dirty_written); DEFINE_WBC_EVENT(wbc_balance_dirty_wait); DEFINE_WBC_EVENT(wbc_writepage); +DECLARE_EVENT_CLASS(writeback_congest_waited_template, + + TP_PROTO(unsigned int usec_timeout, unsigned int usec_delayed), + + TP_ARGS(usec_timeout, usec_delayed), + + TP_STRUCT__entry( + __field( unsigned int, usec_timeout ) + __field( unsigned int, usec_delayed ) + ), + + TP_fast_assign( + __entry->usec_timeout = usec_timeout; + __entry->usec_delayed = usec_delayed; + ), + + TP_printk("usec_timeout=%u usec_delayed=%u", + __entry->usec_timeout, + __entry->usec_delayed) +); + +DEFINE_EVENT(writeback_congest_waited_template, writeback_congestion_wait, + + TP_PROTO(unsigned int usec_timeout, unsigned int usec_delayed), + + TP_ARGS(usec_timeout, usec_delayed) +); + #endif /* _TRACE_WRITEBACK_H */ /* This part must be outside protection */ diff --git a/mm/backing-dev.c b/mm/backing-dev.c index c2bf86f..e891794 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -762,12 +762,17 @@ EXPORT_SYMBOL(set_bdi_congested); long congestion_wait(int sync, long timeout) { long ret; + unsigned long start = jiffies; DEFINE_WAIT(wait); wait_queue_head_t *wqh = &congestion_wqh[sync]; prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE); ret = io_schedule_timeout(timeout); finish_wait(wqh, &wait); + + trace_writeback_congestion_wait(jiffies_to_usecs(timeout), + jiffies_to_usecs(jiffies - start)); + return ret; } EXPORT_SYMBOL(congestion_wait); -- 1.7.1
WARNING: multiple messages have this Message-ID (diff)
From: Mel Gorman <mel@csn.ul.ie> To: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Linux Kernel List <linux-kernel@vger.kernel.org>, Johannes Weiner <hannes@cmpxchg.org>, Minchan Kim <minchan.kim@gmail.com>, Wu Fengguang <fengguang.wu@intel.com>, KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>, KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>, Mel Gorman <mel@csn.ul.ie> Subject: [PATCH 2/8] writeback: Account for time spent congestion_waited Date: Wed, 15 Sep 2010 13:27:45 +0100 [thread overview] Message-ID: <1284553671-31574-3-git-send-email-mel@csn.ul.ie> (raw) In-Reply-To: <1284553671-31574-1-git-send-email-mel@csn.ul.ie> There is strong evidence to indicate a lot of time is being spent in congestion_wait(), some of it unnecessarily. This patch adds a tracepoint for congestion_wait to record when congestion_wait() was called, how long the timeout was for and how long it actually slept. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> --- include/trace/events/writeback.h | 28 ++++++++++++++++++++++++++++ mm/backing-dev.c | 5 +++++ 2 files changed, 33 insertions(+), 0 deletions(-) diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index f345f66..275d477 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -153,6 +153,34 @@ DEFINE_WBC_EVENT(wbc_balance_dirty_written); DEFINE_WBC_EVENT(wbc_balance_dirty_wait); DEFINE_WBC_EVENT(wbc_writepage); +DECLARE_EVENT_CLASS(writeback_congest_waited_template, + + TP_PROTO(unsigned int usec_timeout, unsigned int usec_delayed), + + TP_ARGS(usec_timeout, usec_delayed), + + TP_STRUCT__entry( + __field( unsigned int, usec_timeout ) + __field( unsigned int, usec_delayed ) + ), + + TP_fast_assign( + __entry->usec_timeout = usec_timeout; + __entry->usec_delayed = usec_delayed; + ), + + TP_printk("usec_timeout=%u usec_delayed=%u", + __entry->usec_timeout, + __entry->usec_delayed) +); + +DEFINE_EVENT(writeback_congest_waited_template, writeback_congestion_wait, + + TP_PROTO(unsigned int usec_timeout, unsigned int usec_delayed), + + TP_ARGS(usec_timeout, usec_delayed) +); + #endif /* _TRACE_WRITEBACK_H */ /* This part must be outside protection */ diff --git a/mm/backing-dev.c b/mm/backing-dev.c index c2bf86f..e891794 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -762,12 +762,17 @@ EXPORT_SYMBOL(set_bdi_congested); long congestion_wait(int sync, long timeout) { long ret; + unsigned long start = jiffies; DEFINE_WAIT(wait); wait_queue_head_t *wqh = &congestion_wqh[sync]; prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE); ret = io_schedule_timeout(timeout); finish_wait(wqh, &wait); + + trace_writeback_congestion_wait(jiffies_to_usecs(timeout), + jiffies_to_usecs(jiffies - start)); + return ret; } EXPORT_SYMBOL(congestion_wait); -- 1.7.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2010-09-15 12:27 UTC|newest] Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-09-15 12:27 [PATCH 0/8] Reduce latencies and improve overall reclaim efficiency v2 Mel Gorman 2010-09-15 12:27 ` Mel Gorman 2010-09-15 12:27 ` [PATCH 1/8] tracing, vmscan: Add trace events for LRU list shrinking Mel Gorman 2010-09-15 12:27 ` Mel Gorman 2010-09-15 12:27 ` Mel Gorman [this message] 2010-09-15 12:27 ` [PATCH 2/8] writeback: Account for time spent congestion_waited Mel Gorman 2010-09-15 12:27 ` [PATCH 3/8] vmscan: Synchronous lumpy reclaim should not call congestion_wait() Mel Gorman 2010-09-15 12:27 ` Mel Gorman 2010-09-15 12:27 ` [PATCH 4/8] vmscan: Narrow the scenarios lumpy reclaim uses synchrounous reclaim Mel Gorman 2010-09-15 12:27 ` Mel Gorman 2010-09-15 12:27 ` [PATCH 5/8] vmscan: Remove dead code in shrink_inactive_list() Mel Gorman 2010-09-15 12:27 ` Mel Gorman 2010-09-15 12:27 ` [PATCH 6/8] vmscan: isolated_lru_pages() stop neighbour search if neighbour cannot be isolated Mel Gorman 2010-09-15 12:27 ` Mel Gorman 2010-09-15 12:27 ` [PATCH 7/8] writeback: Do not sleep on the congestion queue if there are no congested BDIs Mel Gorman 2010-09-15 12:27 ` Mel Gorman 2010-09-16 7:59 ` Minchan Kim 2010-09-16 7:59 ` Minchan Kim 2010-09-16 8:23 ` Mel Gorman 2010-09-16 8:23 ` Mel Gorman 2010-09-15 12:27 ` [PATCH 8/8] writeback: Do not sleep on the congestion queue if there are no congested BDIs or if significant congestion is not being encountered in the current zone Mel Gorman 2010-09-15 12:27 ` Mel Gorman 2010-09-16 8:13 ` Minchan Kim 2010-09-16 8:13 ` Minchan Kim 2010-09-16 9:18 ` Mel Gorman 2010-09-16 9:18 ` Mel Gorman 2010-09-16 14:11 ` Minchan Kim 2010-09-16 14:11 ` Minchan Kim 2010-09-16 15:18 ` Mel Gorman 2010-09-16 15:18 ` Mel Gorman 2010-09-16 22:28 ` Andrew Morton 2010-09-16 22:28 ` Andrew Morton 2010-09-20 9:52 ` Mel Gorman 2010-09-20 9:52 ` Mel Gorman 2010-09-21 21:44 ` Andrew Morton 2010-09-21 21:44 ` Andrew Morton 2010-09-21 22:10 ` Mel Gorman 2010-09-21 22:10 ` Mel Gorman 2010-09-21 22:24 ` Andrew Morton 2010-09-21 22:24 ` Andrew Morton 2010-09-20 13:05 ` [PATCH] writeback: Do not sleep on the congestion queue if there are no congested BDIs or if significant congestion is not being encounted in the current zone fix Mel Gorman 2010-09-20 13:05 ` Mel Gorman 2010-09-16 22:28 ` [PATCH 0/8] Reduce latencies and improve overall reclaim efficiency v2 Andrew Morton 2010-09-16 22:28 ` Andrew Morton 2010-09-17 7:52 ` Mel Gorman 2010-09-17 7:52 ` Mel Gorman 2010-10-14 15:28 ` Christian Ehrhardt 2010-10-14 15:28 ` Christian Ehrhardt 2010-10-14 15:28 ` Christian Ehrhardt 2010-10-18 13:55 ` Mel Gorman 2010-10-18 13:55 ` Mel Gorman 2010-10-22 12:29 ` Christian Ehrhardt 2010-10-22 12:29 ` Christian Ehrhardt 2010-10-22 12:29 ` Christian Ehrhardt 2010-11-03 10:50 ` Christian Ehrhardt 2010-11-03 10:50 ` Christian Ehrhardt 2010-11-03 10:50 ` Christian Ehrhardt 2010-11-10 14:37 ` Mel Gorman 2010-11-10 14:37 ` Mel Gorman
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