[PATCH 09/45] writeback: make congestion functions per bdi_writeback
From: Tejun Heo <tj@kernel.org>
Date: 2015-01-06 21:25:46
Also in:
linux-fsdevel, linux-mm, lkml
Subsystem:
memory management, memory management - misc, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
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
@wb and operate on it. 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.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
---
include/linux/backing-dev-defs.h | 14 +++++++++++--
include/linux/backing-dev.h | 43 +++++++++++++++++++++++-----------------
mm/backing-dev.c | 22 ++++++++++----------
3 files changed, 48 insertions(+), 31 deletions(-)
diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h
index 511066f..54a3a9c 100644
--- a/include/linux/backing-dev-defs.h
+++ b/include/linux/backing-dev-defs.h@@ -122,7 +122,17 @@ 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 *wb, int sync); +void set_wb_congested(struct bdi_writeback *wb, int sync); + +static inline void clear_bdi_congested(struct backing_dev_info *bdi, int sync) +{ + clear_wb_congested(&bdi->wb, sync); +} + +static inline void set_bdi_congested(struct backing_dev_info *bdi, int sync) +{ + set_wb_congested(&bdi->wb, sync); +} #endif /* __LINUX_BACKING_DEV_DEFS_H */
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 3722796..be66668 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h@@ -182,27 +182,13 @@ extern struct backing_dev_info noop_backing_dev_info; int writeback_in_progress(struct backing_dev_info *bdi); -static inline int bdi_congested(struct backing_dev_info *bdi, int bdi_bits) +static inline int wb_congested(struct bdi_writeback *wb, int bdi_bits) { + struct backing_dev_info *bdi = wb->bdi; + if (bdi->congested_fn) return bdi->congested_fn(bdi->congested_data, bdi_bits); - return (bdi->wb.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); -} - -static inline int bdi_rw_congested(struct backing_dev_info *bdi) -{ - return bdi_congested(bdi, (1 << WB_sync_congested) | - (1 << WB_async_congested)); + return wb->state & bdi_bits; } long congestion_wait(int sync, long timeout);
@@ -422,4 +408,25 @@ static inline struct bdi_writeback *page_cgwb_wb(struct page *page) #endif /* CONFIG_CGROUP_WRITEBACK */ +static inline int bdi_congested(struct backing_dev_info *bdi, int bdi_bits) +{ + return wb_congested(&bdi->wb, 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); +} + +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 c6dda82..2851278 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c@@ -767,31 +767,31 @@ 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 *wb, 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.state)) - atomic_dec(&nr_bdi_congested[sync]); + if (test_and_clear_bit(bit, &wb->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 *wb, int sync) { enum wb_state bit; bit = sync ? WB_sync_congested : WB_async_congested; - if (!test_and_set_bit(bit, &bdi->wb.state)) - atomic_inc(&nr_bdi_congested[sync]); + if (!test_and_set_bit(bit, &wb->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
@@ -850,7 +850,7 @@ 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();
--
2.1.0
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