From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: Re: [PATCH 27/51] writeback: make congestion functions per bdi_writeback Date: Tue, 30 Jun 2015 16:50:41 +0200 Message-ID: <20150630145041.GM7252@quack.suse.cz> References: <1432329245-5844-1-git-send-email-tj@kernel.org> <1432329245-5844-28-git-send-email-tj@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: axboe@kernel.dk, 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, khlebnikov@yandex-team.ru To: Tejun Heo Return-path: Received: from cantor2.suse.de ([195.135.220.15]:59502 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752321AbbF3Ous (ORCPT ); Tue, 30 Jun 2015 10:50:48 -0400 Content-Disposition: inline In-Reply-To: <1432329245-5844-28-git-send-email-tj@kernel.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Fri 22-05-15 17:13:41, Tejun Heo wrote: > Currently, all congestion functions take bdi (backing_dev_info) and > always operate on the root wb (bdi->wb) and the congestion state from > the block layer is propagated only for the root blkcg. This patch > introduces {set|clear}_wb_congested() and wb_congested() which take a > bdi_writeback_congested and bdi_writeback respectively. The bdi > counteparts are now wrappers invoking the wb based functions on > @bdi->wb. > > While converting clear_bdi_congested() to clear_wb_congested(), the > local variable declaration order between @wqh and @bit is swapped for > cosmetic reason. > > This patch just adds the new wb based functions. The following > patches will apply them. Looks good to me. You can add: Reviewed-by: Jan Kara Honza > > v2: Updated for bdi_writeback_congested. > > Signed-off-by: Tejun Heo > Reviewed-by: Jan Kara > Cc: Jens Axboe > --- > include/linux/backing-dev-defs.h | 14 +++++++++++-- > include/linux/backing-dev.h | 45 +++++++++++++++++++++++----------------- > mm/backing-dev.c | 22 ++++++++++---------- > 3 files changed, 49 insertions(+), 32 deletions(-) > > diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h > index a1e9c40..eb38676 100644 > --- a/include/linux/backing-dev-defs.h > +++ b/include/linux/backing-dev-defs.h > @@ -163,7 +163,17 @@ enum { > BLK_RW_SYNC = 1, > }; > > -void clear_bdi_congested(struct backing_dev_info *bdi, int sync); > -void set_bdi_congested(struct backing_dev_info *bdi, int sync); > +void clear_wb_congested(struct bdi_writeback_congested *congested, int sync); > +void set_wb_congested(struct bdi_writeback_congested *congested, int sync); > + > +static inline void clear_bdi_congested(struct backing_dev_info *bdi, int sync) > +{ > + clear_wb_congested(bdi->wb.congested, sync); > +} > + > +static inline void set_bdi_congested(struct backing_dev_info *bdi, int sync) > +{ > + set_wb_congested(bdi->wb.congested, sync); > +} > > #endif /* __LINUX_BACKING_DEV_DEFS_H */ > diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h > index 8ae59df..2c498a2 100644 > --- a/include/linux/backing-dev.h > +++ b/include/linux/backing-dev.h > @@ -167,27 +167,13 @@ static inline struct backing_dev_info *inode_to_bdi(struct inode *inode) > return sb->s_bdi; > } > > -static inline int bdi_congested(struct backing_dev_info *bdi, int bdi_bits) > +static inline int wb_congested(struct bdi_writeback *wb, int cong_bits) > { > - if (bdi->congested_fn) > - return bdi->congested_fn(bdi->congested_data, bdi_bits); > - return (bdi->wb.congested->state & bdi_bits); > -} > - > -static inline int bdi_read_congested(struct backing_dev_info *bdi) > -{ > - return bdi_congested(bdi, 1 << WB_sync_congested); > -} > - > -static inline int bdi_write_congested(struct backing_dev_info *bdi) > -{ > - return bdi_congested(bdi, 1 << WB_async_congested); > -} > + struct backing_dev_info *bdi = wb->bdi; > > -static inline int bdi_rw_congested(struct backing_dev_info *bdi) > -{ > - return bdi_congested(bdi, (1 << WB_sync_congested) | > - (1 << WB_async_congested)); > + if (bdi->congested_fn) > + return bdi->congested_fn(bdi->congested_data, cong_bits); > + return wb->congested->state & cong_bits; > } > > long congestion_wait(int sync, long timeout); > @@ -454,4 +440,25 @@ static inline void wb_blkcg_offline(struct blkcg *blkcg) > > #endif /* CONFIG_CGROUP_WRITEBACK */ > > +static inline int bdi_congested(struct backing_dev_info *bdi, int cong_bits) > +{ > + return wb_congested(&bdi->wb, cong_bits); > +} > + > +static inline int bdi_read_congested(struct backing_dev_info *bdi) > +{ > + return bdi_congested(bdi, 1 << WB_sync_congested); > +} > + > +static inline int bdi_write_congested(struct backing_dev_info *bdi) > +{ > + return bdi_congested(bdi, 1 << WB_async_congested); > +} > + > +static inline int bdi_rw_congested(struct backing_dev_info *bdi) > +{ > + return bdi_congested(bdi, (1 << WB_sync_congested) | > + (1 << WB_async_congested)); > +} > + > #endif /* _LINUX_BACKING_DEV_H */ > diff --git a/mm/backing-dev.c b/mm/backing-dev.c > index 4c9386c..5029c4a 100644 > --- a/mm/backing-dev.c > +++ b/mm/backing-dev.c > @@ -896,31 +896,31 @@ static wait_queue_head_t congestion_wqh[2] = { > __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]), > __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1]) > }; > -static atomic_t nr_bdi_congested[2]; > +static atomic_t nr_wb_congested[2]; > > -void clear_bdi_congested(struct backing_dev_info *bdi, int sync) > +void clear_wb_congested(struct bdi_writeback_congested *congested, int sync) > { > - enum wb_state bit; > wait_queue_head_t *wqh = &congestion_wqh[sync]; > + enum wb_state bit; > > bit = sync ? WB_sync_congested : WB_async_congested; > - if (test_and_clear_bit(bit, &bdi->wb.congested->state)) > - atomic_dec(&nr_bdi_congested[sync]); > + if (test_and_clear_bit(bit, &congested->state)) > + atomic_dec(&nr_wb_congested[sync]); > smp_mb__after_atomic(); > if (waitqueue_active(wqh)) > wake_up(wqh); > } > -EXPORT_SYMBOL(clear_bdi_congested); > +EXPORT_SYMBOL(clear_wb_congested); > > -void set_bdi_congested(struct backing_dev_info *bdi, int sync) > +void set_wb_congested(struct bdi_writeback_congested *congested, int sync) > { > enum wb_state bit; > > bit = sync ? WB_sync_congested : WB_async_congested; > - if (!test_and_set_bit(bit, &bdi->wb.congested->state)) > - atomic_inc(&nr_bdi_congested[sync]); > + if (!test_and_set_bit(bit, &congested->state)) > + atomic_inc(&nr_wb_congested[sync]); > } > -EXPORT_SYMBOL(set_bdi_congested); > +EXPORT_SYMBOL(set_wb_congested); > > /** > * congestion_wait - wait for a backing_dev to become uncongested > @@ -979,7 +979,7 @@ long wait_iff_congested(struct zone *zone, int sync, long timeout) > * encountered in the current zone, yield if necessary instead > * of sleeping on the congestion queue > */ > - if (atomic_read(&nr_bdi_congested[sync]) == 0 || > + if (atomic_read(&nr_wb_congested[sync]) == 0 || > !test_bit(ZONE_CONGESTED, &zone->flags)) { > cond_resched(); > > -- > 2.4.0 > -- Jan Kara SUSE Labs, CR