From: Tejun Heo <tj@kernel.org> To: axboe@kernel.dk Cc: linux-kernel@vger.kernel.org, jack@suse.cz, hch@infradead.org, hannes@cmpxchg.org, linux-fsdevel@vger.kernel.org, vgoyal@redhat.com, lizefan@huawei.com, cgroups@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.cz, clm@fb.com, fengguang.wu@intel.com, david@fromorbit.com, gthelen@google.com, Tejun Heo <tj@kernel.org> Subject: [PATCH 02/18] writeback: reorganize [__]wb_update_bandwidth() Date: Mon, 23 Mar 2015 01:07:31 -0400 [thread overview] Message-ID: <1427087267-16592-3-git-send-email-tj@kernel.org> (raw) In-Reply-To: <1427087267-16592-1-git-send-email-tj@kernel.org> __wb_update_bandwidth() is called from two places - fs/fs-writeback.c::balance_dirty_pages() and mm/page-writeback.c::wb_writeback(). The latter updates only the write bandwidth while the former also deals with the dirty ratelimit. The two callsites are distinguished by whether @thresh parameter is zero or not, which is cryptic. In addition, the two files define their own different versions of wb_update_bandwidth() on top of __wb_update_bandwidth(), which is confusing to say the least. This patch cleans up [__]wb_update_bandwidth() in the following ways. * __wb_update_bandwidth() now takes explicit @update_ratelimit parameter to gate dirty ratelimit handling. * mm/page-writeback.c::wb_update_bandwidth() is flattened into its caller - balance_dirty_pages(). * fs/fs-writeback.c::wb_update_bandwidth() is moved to mm/page-writeback.c and __wb_update_bandwidth() is made static. * While at it, add a lockdep assertion to __wb_update_bandwidth(). Except for the lockdep addition, this is pure reorganization and doesn't introduce any behavioral changes. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Greg Thelen <gthelen@google.com> --- fs/fs-writeback.c | 10 ---------- include/linux/writeback.h | 9 +-------- mm/page-writeback.c | 45 ++++++++++++++++++++++----------------------- 3 files changed, 23 insertions(+), 41 deletions(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 890cff1..3d9b360 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1079,16 +1079,6 @@ static bool over_bground_thresh(struct bdi_writeback *wb) } /* - * Called under wb->list_lock. If there are multiple wb per bdi, - * only the flusher working on the first wb should do it. - */ -static void wb_update_bandwidth(struct bdi_writeback *wb, - unsigned long start_time) -{ - __wb_update_bandwidth(wb, 0, 0, 0, 0, 0, start_time); -} - -/* * Explicit flushing or periodic writeback of "old" data. * * Define "old": the first time one of an inode's pages is dirtied, we mark the diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 75349bb..82e0e39 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -154,14 +154,7 @@ int dirty_writeback_centisecs_handler(struct ctl_table *, int, void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty); unsigned long wb_dirty_limit(struct bdi_writeback *wb, unsigned long dirty); -void __wb_update_bandwidth(struct bdi_writeback *wb, - unsigned long thresh, - unsigned long bg_thresh, - unsigned long dirty, - unsigned long bdi_thresh, - unsigned long bdi_dirty, - unsigned long start_time); - +void wb_update_bandwidth(struct bdi_writeback *wb, unsigned long start_time); void page_writeback_init(void); void balance_dirty_pages_ratelimited(struct address_space *mapping); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index fd441ea..d9ebabe 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1160,19 +1160,22 @@ static void wb_update_dirty_ratelimit(struct bdi_writeback *wb, trace_bdi_dirty_ratelimit(wb->bdi, dirty_rate, task_ratelimit); } -void __wb_update_bandwidth(struct bdi_writeback *wb, - unsigned long thresh, - unsigned long bg_thresh, - unsigned long dirty, - unsigned long wb_thresh, - unsigned long wb_dirty, - unsigned long start_time) +static void __wb_update_bandwidth(struct bdi_writeback *wb, + unsigned long thresh, + unsigned long bg_thresh, + unsigned long dirty, + unsigned long wb_thresh, + unsigned long wb_dirty, + unsigned long start_time, + bool update_ratelimit) { unsigned long now = jiffies; unsigned long elapsed = now - wb->bw_time_stamp; unsigned long dirtied; unsigned long written; + lockdep_assert_held(&wb->list_lock); + /* * rate-limit, only update once every 200ms. */ @@ -1189,7 +1192,7 @@ void __wb_update_bandwidth(struct bdi_writeback *wb, if (elapsed > HZ && time_before(wb->bw_time_stamp, start_time)) goto snapshot; - if (thresh) { + if (update_ratelimit) { global_update_bandwidth(thresh, dirty, now); wb_update_dirty_ratelimit(wb, thresh, bg_thresh, dirty, wb_thresh, wb_dirty, @@ -1203,20 +1206,9 @@ snapshot: wb->bw_time_stamp = now; } -static void wb_update_bandwidth(struct bdi_writeback *wb, - unsigned long thresh, - unsigned long bg_thresh, - unsigned long dirty, - unsigned long wb_thresh, - unsigned long wb_dirty, - unsigned long start_time) +void wb_update_bandwidth(struct bdi_writeback *wb, unsigned long start_time) { - if (time_is_after_eq_jiffies(wb->bw_time_stamp + BANDWIDTH_INTERVAL)) - return; - spin_lock(&wb->list_lock); - __wb_update_bandwidth(wb, thresh, bg_thresh, dirty, - wb_thresh, wb_dirty, start_time); - spin_unlock(&wb->list_lock); + __wb_update_bandwidth(wb, 0, 0, 0, 0, 0, start_time, false); } /* @@ -1467,8 +1459,15 @@ static void balance_dirty_pages(struct address_space *mapping, if (dirty_exceeded && !wb->dirty_exceeded) wb->dirty_exceeded = 1; - wb_update_bandwidth(wb, dirty_thresh, background_thresh, - nr_dirty, wb_thresh, wb_dirty, start_time); + if (time_is_before_jiffies(wb->bw_time_stamp + + BANDWIDTH_INTERVAL)) { + spin_lock(&wb->list_lock); + __wb_update_bandwidth(wb, dirty_thresh, + background_thresh, nr_dirty, + wb_thresh, wb_dirty, start_time, + true); + spin_unlock(&wb->list_lock); + } dirty_ratelimit = wb->dirty_ratelimit; pos_ratio = wb_position_ratio(wb, dirty_thresh, -- 2.1.0
WARNING: multiple messages have this Message-ID (diff)
From: Tejun Heo <tj@kernel.org> To: axboe@kernel.dk Cc: linux-kernel@vger.kernel.org, jack@suse.cz, hch@infradead.org, hannes@cmpxchg.org, linux-fsdevel@vger.kernel.org, vgoyal@redhat.com, lizefan@huawei.com, cgroups@vger.kernel.org, linux-mm@kvack.org, mhocko@suse.cz, clm@fb.com, fengguang.wu@intel.com, david@fromorbit.com, gthelen@google.com, Tejun Heo <tj@kernel.org> Subject: [PATCH 02/18] writeback: reorganize [__]wb_update_bandwidth() Date: Mon, 23 Mar 2015 01:07:31 -0400 [thread overview] Message-ID: <1427087267-16592-3-git-send-email-tj@kernel.org> (raw) In-Reply-To: <1427087267-16592-1-git-send-email-tj@kernel.org> __wb_update_bandwidth() is called from two places - fs/fs-writeback.c::balance_dirty_pages() and mm/page-writeback.c::wb_writeback(). The latter updates only the write bandwidth while the former also deals with the dirty ratelimit. The two callsites are distinguished by whether @thresh parameter is zero or not, which is cryptic. In addition, the two files define their own different versions of wb_update_bandwidth() on top of __wb_update_bandwidth(), which is confusing to say the least. This patch cleans up [__]wb_update_bandwidth() in the following ways. * __wb_update_bandwidth() now takes explicit @update_ratelimit parameter to gate dirty ratelimit handling. * mm/page-writeback.c::wb_update_bandwidth() is flattened into its caller - balance_dirty_pages(). * fs/fs-writeback.c::wb_update_bandwidth() is moved to mm/page-writeback.c and __wb_update_bandwidth() is made static. * While at it, add a lockdep assertion to __wb_update_bandwidth(). Except for the lockdep addition, this is pure reorganization and doesn't introduce any behavioral changes. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Greg Thelen <gthelen@google.com> --- fs/fs-writeback.c | 10 ---------- include/linux/writeback.h | 9 +-------- mm/page-writeback.c | 45 ++++++++++++++++++++++----------------------- 3 files changed, 23 insertions(+), 41 deletions(-) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 890cff1..3d9b360 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1079,16 +1079,6 @@ static bool over_bground_thresh(struct bdi_writeback *wb) } /* - * Called under wb->list_lock. If there are multiple wb per bdi, - * only the flusher working on the first wb should do it. - */ -static void wb_update_bandwidth(struct bdi_writeback *wb, - unsigned long start_time) -{ - __wb_update_bandwidth(wb, 0, 0, 0, 0, 0, start_time); -} - -/* * Explicit flushing or periodic writeback of "old" data. * * Define "old": the first time one of an inode's pages is dirtied, we mark the diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 75349bb..82e0e39 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -154,14 +154,7 @@ int dirty_writeback_centisecs_handler(struct ctl_table *, int, void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty); unsigned long wb_dirty_limit(struct bdi_writeback *wb, unsigned long dirty); -void __wb_update_bandwidth(struct bdi_writeback *wb, - unsigned long thresh, - unsigned long bg_thresh, - unsigned long dirty, - unsigned long bdi_thresh, - unsigned long bdi_dirty, - unsigned long start_time); - +void wb_update_bandwidth(struct bdi_writeback *wb, unsigned long start_time); void page_writeback_init(void); void balance_dirty_pages_ratelimited(struct address_space *mapping); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index fd441ea..d9ebabe 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1160,19 +1160,22 @@ static void wb_update_dirty_ratelimit(struct bdi_writeback *wb, trace_bdi_dirty_ratelimit(wb->bdi, dirty_rate, task_ratelimit); } -void __wb_update_bandwidth(struct bdi_writeback *wb, - unsigned long thresh, - unsigned long bg_thresh, - unsigned long dirty, - unsigned long wb_thresh, - unsigned long wb_dirty, - unsigned long start_time) +static void __wb_update_bandwidth(struct bdi_writeback *wb, + unsigned long thresh, + unsigned long bg_thresh, + unsigned long dirty, + unsigned long wb_thresh, + unsigned long wb_dirty, + unsigned long start_time, + bool update_ratelimit) { unsigned long now = jiffies; unsigned long elapsed = now - wb->bw_time_stamp; unsigned long dirtied; unsigned long written; + lockdep_assert_held(&wb->list_lock); + /* * rate-limit, only update once every 200ms. */ @@ -1189,7 +1192,7 @@ void __wb_update_bandwidth(struct bdi_writeback *wb, if (elapsed > HZ && time_before(wb->bw_time_stamp, start_time)) goto snapshot; - if (thresh) { + if (update_ratelimit) { global_update_bandwidth(thresh, dirty, now); wb_update_dirty_ratelimit(wb, thresh, bg_thresh, dirty, wb_thresh, wb_dirty, @@ -1203,20 +1206,9 @@ snapshot: wb->bw_time_stamp = now; } -static void wb_update_bandwidth(struct bdi_writeback *wb, - unsigned long thresh, - unsigned long bg_thresh, - unsigned long dirty, - unsigned long wb_thresh, - unsigned long wb_dirty, - unsigned long start_time) +void wb_update_bandwidth(struct bdi_writeback *wb, unsigned long start_time) { - if (time_is_after_eq_jiffies(wb->bw_time_stamp + BANDWIDTH_INTERVAL)) - return; - spin_lock(&wb->list_lock); - __wb_update_bandwidth(wb, thresh, bg_thresh, dirty, - wb_thresh, wb_dirty, start_time); - spin_unlock(&wb->list_lock); + __wb_update_bandwidth(wb, 0, 0, 0, 0, 0, start_time, false); } /* @@ -1467,8 +1459,15 @@ static void balance_dirty_pages(struct address_space *mapping, if (dirty_exceeded && !wb->dirty_exceeded) wb->dirty_exceeded = 1; - wb_update_bandwidth(wb, dirty_thresh, background_thresh, - nr_dirty, wb_thresh, wb_dirty, start_time); + if (time_is_before_jiffies(wb->bw_time_stamp + + BANDWIDTH_INTERVAL)) { + spin_lock(&wb->list_lock); + __wb_update_bandwidth(wb, dirty_thresh, + background_thresh, nr_dirty, + wb_thresh, wb_dirty, start_time, + true); + spin_unlock(&wb->list_lock); + } dirty_ratelimit = wb->dirty_ratelimit; pos_ratio = wb_position_ratio(wb, dirty_thresh, -- 2.1.0 -- 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:[~2015-03-23 5:08 UTC|newest] Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-03-23 5:07 [PATCHSET 2/3 block/for-4.1/core] writeback: cgroup writeback backpressure propagation Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 01/18] memcg: make mem_cgroup_read_{stat|event}() iterate possible cpus instead of online Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-25 22:39 ` [PATCH 1.5/18] writeback: clean up wb_dirty_limit() Tejun Heo 2015-03-25 22:39 ` Tejun Heo 2015-03-25 22:39 ` Tejun Heo 2015-03-25 22:39 ` Tejun Heo 2015-03-23 5:07 ` Tejun Heo [this message] 2015-03-23 5:07 ` [PATCH 02/18] writeback: reorganize [__]wb_update_bandwidth() Tejun Heo 2015-03-23 5:07 ` [PATCH 03/18] writeback: implement wb_domain Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 04/18] writeback: move global_dirty_limit into wb_domain Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 05/18] writeback: consolidate dirty throttle parameters into dirty_throttle_control Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 06/18] writeback: add dirty_throttle_control->wb_bg_thresh Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 07/18] writeback: make __wb_dirty_limit() take dirty_throttle_control Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-25 22:42 ` [PATCH v2 07/18] writeback: make __wb_calc_thresh() " Tejun Heo 2015-03-25 22:42 ` Tejun Heo 2015-03-25 22:42 ` Tejun Heo 2015-03-25 22:42 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 08/18] writeback: add dirty_throttle_control->pos_ratio Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 09/18] writeback: add dirty_throttle_control->wb_completions Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 10/18] writeback: add dirty_throttle_control->dom Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 11/18] writeback: make __wb_writeout_inc() and hard_dirty_limit() take wb_domaas a parameter Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 12/18] writeback: separate out domain_dirty_limits() Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 13/18] writeback: move over_bground_thresh() to mm/page-writeback.c Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 14/18] writeback: update wb_over_bg_thresh() to use wb_domain aware operations Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 15/18] writeback: implement memcg wb_domain Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 16/18] writeback: reset wb_domain->dirty_limit[_tstmp] when memcg domain size changes Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 17/18] writeback: implement memcg writeback domain based throttling Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:07 ` [PATCH 18/18] mm: vmscan: remove memcg stalling on writeback pages during direct reclaim Tejun Heo 2015-03-23 5:07 ` Tejun Heo 2015-03-23 5:27 ` Tejun Heo 2015-03-23 5:27 ` Tejun Heo 2015-03-25 22:26 ` [PATCH v2 18/18] mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use Tejun Heo 2015-03-25 22:26 ` Tejun Heo 2015-03-25 22:26 ` Tejun Heo 2015-03-25 22:26 ` Tejun Heo
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