From 9ba4b2dfafaa711b41cc2102b0e9a529f3981218 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 20 Sep 2017 08:58:25 -0600 Subject: fs: kill 'nr_pages' argument from wakeup_flusher_threads() Everybody is passing in 0 now, let's get rid of the argument. Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 245c430a2e41..bb6148dc6d24 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1947,12 +1947,12 @@ void wb_workfn(struct work_struct *work) } /* - * Start writeback of `nr_pages' pages. If `nr_pages' is zero, write back - * the whole world. + * Wakeup the flusher threads to start writeback of all currently dirty pages */ -void wakeup_flusher_threads(long nr_pages, enum wb_reason reason) +void wakeup_flusher_threads(enum wb_reason reason) { struct backing_dev_info *bdi; + long nr_pages; /* * If we are expecting writeback progress we must submit plugged IO. @@ -1960,8 +1960,7 @@ void wakeup_flusher_threads(long nr_pages, enum wb_reason reason) if (blk_needs_flush_plug(current)) blk_schedule_flush_plug(current); - if (!nr_pages) - nr_pages = get_nr_dirty_pages(); + nr_pages = get_nr_dirty_pages(); rcu_read_lock(); list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) { -- cgit v1.2.3 From d31cd9d326f216fca9a602dddac254f668f5dcd6 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 27 Sep 2017 13:28:18 -0600 Subject: writeback: switch wakeup_flusher_threads() to cyclic writeback We're writing back the full range of dirty pages on the devices, there's no point in making this special and not do normal range cyclic writeback. Reviewed-by: Jan Kara Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index bb6148dc6d24..65e6992d8719 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1971,7 +1971,7 @@ void wakeup_flusher_threads(enum wb_reason reason) list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node) wb_start_writeback(wb, wb_split_bdi_pages(wb, nr_pages), - false, reason); + true, reason); } rcu_read_unlock(); } -- cgit v1.2.3 From 47410d88f665486bf91f02242ab5d5692b8887ac Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 28 Sep 2017 11:25:03 -0600 Subject: writeback: remove 'range_cyclic' argument for wb_start_writeback() All the callers pass in 'true' for range_cyclic, so kill the argument. Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 6 +++--- include/linux/backing-dev.h | 2 +- mm/page-writeback.c | 4 ++-- 3 files changed, 6 insertions(+), 6 deletions(-) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 65e6992d8719..fe555bce886c 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -934,7 +934,7 @@ static void bdi_split_work_to_wbs(struct backing_dev_info *bdi, #endif /* CONFIG_CGROUP_WRITEBACK */ void wb_start_writeback(struct bdi_writeback *wb, long nr_pages, - bool range_cyclic, enum wb_reason reason) + enum wb_reason reason) { struct wb_writeback_work *work; @@ -955,7 +955,7 @@ void wb_start_writeback(struct bdi_writeback *wb, long nr_pages, work->sync_mode = WB_SYNC_NONE; work->nr_pages = nr_pages; - work->range_cyclic = range_cyclic; + work->range_cyclic = 1; work->reason = reason; work->auto_free = 1; @@ -1971,7 +1971,7 @@ void wakeup_flusher_threads(enum wb_reason reason) list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node) wb_start_writeback(wb, wb_split_bdi_pages(wb, nr_pages), - true, reason); + reason); } rcu_read_unlock(); } diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 854e1bdd0b2a..0f63493de9e7 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -39,7 +39,7 @@ static inline struct backing_dev_info *bdi_alloc(gfp_t gfp_mask) } void wb_start_writeback(struct bdi_writeback *wb, long nr_pages, - bool range_cyclic, enum wb_reason reason); + enum wb_reason reason); void wb_start_background_writeback(struct bdi_writeback *wb); void wb_workfn(struct work_struct *work); void wb_wakeup_delayed(struct bdi_writeback *wb); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0b9c5cbe8eba..dede53355123 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -1994,8 +1994,8 @@ void laptop_mode_timer_fn(unsigned long data) rcu_read_lock(); list_for_each_entry_rcu(wb, &q->backing_dev_info->wb_list, bdi_node) if (wb_has_dirty_io(wb)) - wb_start_writeback(wb, nr_pages, true, - WB_REASON_LAPTOP_TIMER); + wb_start_writeback(wb, nr_pages, + WB_REASON_LAPTOP_TIMER); rcu_read_unlock(); } -- cgit v1.2.3 From 595043e5f9ef1d8263bd9fda215cade489227491 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 28 Sep 2017 11:26:59 -0600 Subject: writeback: provide a wakeup_flusher_threads_bdi() Similar to wakeup_flusher_threads(), except that we only wake up the flusher threads on the specified backing device. No functional changes in this patch. Acked-by: Johannes Weiner Tested-by: Chris Mason Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 39 +++++++++++++++++++++++++++++---------- include/linux/writeback.h | 2 ++ 2 files changed, 31 insertions(+), 10 deletions(-) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index fe555bce886c..9f39829459dc 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1946,6 +1946,33 @@ void wb_workfn(struct work_struct *work) current->flags &= ~PF_SWAPWRITE; } +/* + * Start writeback of `nr_pages' pages on this bdi. If `nr_pages' is zero, + * write back the whole world. + */ +static void __wakeup_flusher_threads_bdi(struct backing_dev_info *bdi, + long nr_pages, enum wb_reason reason) +{ + struct bdi_writeback *wb; + + if (!bdi_has_dirty_io(bdi)) + return; + + list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node) + wb_start_writeback(wb, wb_split_bdi_pages(wb, nr_pages), + reason); +} + +void wakeup_flusher_threads_bdi(struct backing_dev_info *bdi, + enum wb_reason reason) +{ + long nr_pages = get_nr_dirty_pages(); + + rcu_read_lock(); + __wakeup_flusher_threads_bdi(bdi, nr_pages, reason); + rcu_read_unlock(); +} + /* * Wakeup the flusher threads to start writeback of all currently dirty pages */ @@ -1963,16 +1990,8 @@ void wakeup_flusher_threads(enum wb_reason reason) nr_pages = get_nr_dirty_pages(); rcu_read_lock(); - list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) { - struct bdi_writeback *wb; - - if (!bdi_has_dirty_io(bdi)) - continue; - - list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node) - wb_start_writeback(wb, wb_split_bdi_pages(wb, nr_pages), - reason); - } + list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) + __wakeup_flusher_threads_bdi(bdi, nr_pages, reason); rcu_read_unlock(); } diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 1f9c6db5e29a..9c0091678af4 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -190,6 +190,8 @@ bool try_to_writeback_inodes_sb_nr(struct super_block *, unsigned long nr, enum wb_reason reason); void sync_inodes_sb(struct super_block *); void wakeup_flusher_threads(enum wb_reason reason); +void wakeup_flusher_threads_bdi(struct backing_dev_info *bdi, + enum wb_reason reason); void inode_wait_for_writeback(struct inode *inode); /* writeback.h requires fs.h; it, too, is not included from here. */ -- cgit v1.2.3 From 9dfb176fae57a1dea68531fd25e867037e4d9bac Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 28 Sep 2017 11:28:55 -0600 Subject: writeback: make wb_start_writeback() static We don't have any callers outside of fs-writeback.c anymore, make it private. Acked-by: Johannes Weiner Tested-by: Chris Mason Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 4 ++-- include/linux/backing-dev.h | 2 -- 2 files changed, 2 insertions(+), 4 deletions(-) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 9f39829459dc..f1042061eaad 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -933,8 +933,8 @@ static void bdi_split_work_to_wbs(struct backing_dev_info *bdi, #endif /* CONFIG_CGROUP_WRITEBACK */ -void wb_start_writeback(struct bdi_writeback *wb, long nr_pages, - enum wb_reason reason) +static void wb_start_writeback(struct bdi_writeback *wb, long nr_pages, + enum wb_reason reason) { struct wb_writeback_work *work; diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 0f63493de9e7..157e950a70dc 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -38,8 +38,6 @@ static inline struct backing_dev_info *bdi_alloc(gfp_t gfp_mask) return bdi_alloc_node(gfp_mask, NUMA_NO_NODE); } -void wb_start_writeback(struct bdi_writeback *wb, long nr_pages, - enum wb_reason reason); void wb_start_background_writeback(struct bdi_writeback *wb); void wb_workfn(struct work_struct *work); void wb_wakeup_delayed(struct bdi_writeback *wb); -- cgit v1.2.3 From e8e8a0c6c9bfc0b320671166dd795f413f636773 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 28 Sep 2017 11:31:22 -0600 Subject: writeback: move nr_pages == 0 logic to one location Now that we have no external callers of wb_start_writeback(), we can shuffle the passing in of 'nr_pages'. Everybody passes in 0 at this point, so just kill the argument and move the dirty count retrieval to that function. Acked-by: Johannes Weiner Tested-by: Chris Mason Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 41 +++++++++++++++++------------------------ 1 file changed, 17 insertions(+), 24 deletions(-) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index f1042061eaad..424577152eb5 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -933,8 +933,18 @@ static void bdi_split_work_to_wbs(struct backing_dev_info *bdi, #endif /* CONFIG_CGROUP_WRITEBACK */ -static void wb_start_writeback(struct bdi_writeback *wb, long nr_pages, - enum wb_reason reason) +/* + * Add in the number of potentially dirty inodes, because each inode + * write can dirty pagecache in the underlying blockdev. + */ +static unsigned long get_nr_dirty_pages(void) +{ + return global_node_page_state(NR_FILE_DIRTY) + + global_node_page_state(NR_UNSTABLE_NFS) + + get_nr_dirty_inodes(); +} + +static void wb_start_writeback(struct bdi_writeback *wb, enum wb_reason reason) { struct wb_writeback_work *work; @@ -954,7 +964,7 @@ static void wb_start_writeback(struct bdi_writeback *wb, long nr_pages, } work->sync_mode = WB_SYNC_NONE; - work->nr_pages = nr_pages; + work->nr_pages = wb_split_bdi_pages(wb, get_nr_dirty_pages()); work->range_cyclic = 1; work->reason = reason; work->auto_free = 1; @@ -1814,17 +1824,6 @@ static struct wb_writeback_work *get_next_work_item(struct bdi_writeback *wb) return work; } -/* - * Add in the number of potentially dirty inodes, because each inode - * write can dirty pagecache in the underlying blockdev. - */ -static unsigned long get_nr_dirty_pages(void) -{ - return global_node_page_state(NR_FILE_DIRTY) + - global_node_page_state(NR_UNSTABLE_NFS) + - get_nr_dirty_inodes(); -} - static long wb_check_background_flush(struct bdi_writeback *wb) { if (wb_over_bg_thresh(wb)) { @@ -1951,7 +1950,7 @@ void wb_workfn(struct work_struct *work) * write back the whole world. */ static void __wakeup_flusher_threads_bdi(struct backing_dev_info *bdi, - long nr_pages, enum wb_reason reason) + enum wb_reason reason) { struct bdi_writeback *wb; @@ -1959,17 +1958,14 @@ static void __wakeup_flusher_threads_bdi(struct backing_dev_info *bdi, return; list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node) - wb_start_writeback(wb, wb_split_bdi_pages(wb, nr_pages), - reason); + wb_start_writeback(wb, reason); } void wakeup_flusher_threads_bdi(struct backing_dev_info *bdi, enum wb_reason reason) { - long nr_pages = get_nr_dirty_pages(); - rcu_read_lock(); - __wakeup_flusher_threads_bdi(bdi, nr_pages, reason); + __wakeup_flusher_threads_bdi(bdi, reason); rcu_read_unlock(); } @@ -1979,7 +1975,6 @@ void wakeup_flusher_threads_bdi(struct backing_dev_info *bdi, void wakeup_flusher_threads(enum wb_reason reason) { struct backing_dev_info *bdi; - long nr_pages; /* * If we are expecting writeback progress we must submit plugged IO. @@ -1987,11 +1982,9 @@ void wakeup_flusher_threads(enum wb_reason reason) if (blk_needs_flush_plug(current)) blk_schedule_flush_plug(current); - nr_pages = get_nr_dirty_pages(); - rcu_read_lock(); list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) - __wakeup_flusher_threads_bdi(bdi, nr_pages, reason); + __wakeup_flusher_threads_bdi(bdi, reason); rcu_read_unlock(); } -- cgit v1.2.3 From aac8d41cd438f25bf3110fc6b98f1d16d7dbc169 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 28 Sep 2017 11:31:55 -0600 Subject: writeback: only allow one inflight and pending full flush When someone calls wakeup_flusher_threads() or wakeup_flusher_threads_bdi(), they schedule writeback of all dirty pages in the system (or on that bdi). If we are tight on memory, we can get tons of these queued from kswapd/vmscan. This causes (at least) two problems: 1) We consume a ton of memory just allocating writeback work items. We've seen as much as 600 million of these writeback work items pending. That's a lot of memory to pointlessly hold hostage, while the box is under memory pressure. 2) We spend so much time processing these work items, that we introduce a softlockup in writeback processing. This is because each of the writeback work items don't end up doing any work (it's hard when you have millions of identical ones coming in to the flush machinery), so we just sit in a tight loop pulling work items and deleting/freeing them. Fix this by adding a 'start_all' bit to the writeback structure, and set that when someone attempts to flush all dirty pages. The bit is cleared when we start writeback on that work item. If the bit is already set when we attempt to queue !nr_pages writeback, then we simply ignore it. This provides us one full flush in flight, with one pending as well, and makes for more efficient handling of this type of writeback. Acked-by: Johannes Weiner Tested-by: Chris Mason Reviewed-by: Jan Kara Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 25 +++++++++++++++++++++++++ include/linux/backing-dev-defs.h | 1 + 2 files changed, 26 insertions(+) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 424577152eb5..399619c97567 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -53,6 +53,7 @@ struct wb_writeback_work { unsigned int for_background:1; unsigned int for_sync:1; /* sync(2) WB_SYNC_ALL writeback */ unsigned int auto_free:1; /* free on completion */ + unsigned int start_all:1; /* nr_pages == 0 (all) writeback */ enum wb_reason reason; /* why was writeback initiated? */ struct list_head list; /* pending work list */ @@ -951,6 +952,20 @@ static void wb_start_writeback(struct bdi_writeback *wb, enum wb_reason reason) if (!wb_has_dirty_io(wb)) return; + /* + * All callers of this function want to start writeback of all + * dirty pages. Places like vmscan can call this at a very + * high frequency, causing pointless allocations of tons of + * work items and keeping the flusher threads busy retrieving + * that work. Ensure that we only allow one of them pending and + * inflight at the time. It doesn't matter if we race a little + * bit on this, so use the faster separate test/set bit variants. + */ + if (test_bit(WB_start_all, &wb->state)) + return; + + set_bit(WB_start_all, &wb->state); + /* * This is WB_SYNC_NONE writeback, so if allocation fails just * wakeup the thread for old dirty data writeback @@ -958,6 +973,7 @@ static void wb_start_writeback(struct bdi_writeback *wb, enum wb_reason reason) work = kzalloc(sizeof(*work), GFP_NOWAIT | __GFP_NOMEMALLOC | __GFP_NOWARN); if (!work) { + clear_bit(WB_start_all, &wb->state); trace_writeback_nowork(wb); wb_wakeup(wb); return; @@ -968,6 +984,7 @@ static void wb_start_writeback(struct bdi_writeback *wb, enum wb_reason reason) work->range_cyclic = 1; work->reason = reason; work->auto_free = 1; + work->start_all = 1; wb_queue_work(wb, work); } @@ -1821,6 +1838,14 @@ static struct wb_writeback_work *get_next_work_item(struct bdi_writeback *wb) list_del_init(&work->list); } spin_unlock_bh(&wb->work_lock); + + /* + * Once we start processing a work item that had !nr_pages, + * clear the wb state bit for that so we can allow more. + */ + if (work && work->start_all) + clear_bit(WB_start_all, &wb->state); + return work; } diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index 866c433e7d32..420de5c7c7f9 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -24,6 +24,7 @@ enum wb_state { WB_shutting_down, /* wb_shutdown() in progress */ WB_writeback_running, /* Writeback is in progress */ WB_has_dirty_io, /* Dirty inodes on ->b_{dirty|io|more_io} */ + WB_start_all, /* nr_pages == 0 (all) work pending */ }; enum wb_congested_state { -- cgit v1.2.3 From 85009b4f5f0399669a44f07cb9a5622c0e71d419 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sat, 30 Sep 2017 02:09:06 -0600 Subject: writeback: eliminate work item allocation in bd_start_writeback() Handle start-all writeback like we do periodic or kupdate style writeback - by marking the bdi_writeback as needing a full flush, and simply waking the thread. This eliminates the need to allocate and queue a specific work item just for this purpose. After this change, we truly only ever have one of them running at any point in time. We mark the need to start all flushes, and the writeback thread will clear it once it has processed the request. Reviewed-by: Jan Kara Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 71 +++++++++++++++++++--------------------- include/linux/backing-dev-defs.h | 23 +++++++++++++ include/linux/writeback.h | 22 ------------- include/trace/events/writeback.h | 1 - 4 files changed, 57 insertions(+), 60 deletions(-) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 399619c97567..9e24d604c59c 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -53,7 +53,6 @@ struct wb_writeback_work { unsigned int for_background:1; unsigned int for_sync:1; /* sync(2) WB_SYNC_ALL writeback */ unsigned int auto_free:1; /* free on completion */ - unsigned int start_all:1; /* nr_pages == 0 (all) writeback */ enum wb_reason reason; /* why was writeback initiated? */ struct list_head list; /* pending work list */ @@ -947,8 +946,6 @@ static unsigned long get_nr_dirty_pages(void) static void wb_start_writeback(struct bdi_writeback *wb, enum wb_reason reason) { - struct wb_writeback_work *work; - if (!wb_has_dirty_io(wb)) return; @@ -958,35 +955,14 @@ static void wb_start_writeback(struct bdi_writeback *wb, enum wb_reason reason) * high frequency, causing pointless allocations of tons of * work items and keeping the flusher threads busy retrieving * that work. Ensure that we only allow one of them pending and - * inflight at the time. It doesn't matter if we race a little - * bit on this, so use the faster separate test/set bit variants. + * inflight at the time. */ - if (test_bit(WB_start_all, &wb->state)) + if (test_bit(WB_start_all, &wb->state) || + test_and_set_bit(WB_start_all, &wb->state)) return; - set_bit(WB_start_all, &wb->state); - - /* - * This is WB_SYNC_NONE writeback, so if allocation fails just - * wakeup the thread for old dirty data writeback - */ - work = kzalloc(sizeof(*work), - GFP_NOWAIT | __GFP_NOMEMALLOC | __GFP_NOWARN); - if (!work) { - clear_bit(WB_start_all, &wb->state); - trace_writeback_nowork(wb); - wb_wakeup(wb); - return; - } - - work->sync_mode = WB_SYNC_NONE; - work->nr_pages = wb_split_bdi_pages(wb, get_nr_dirty_pages()); - work->range_cyclic = 1; - work->reason = reason; - work->auto_free = 1; - work->start_all = 1; - - wb_queue_work(wb, work); + wb->start_all_reason = reason; + wb_wakeup(wb); } /** @@ -1838,14 +1814,6 @@ static struct wb_writeback_work *get_next_work_item(struct bdi_writeback *wb) list_del_init(&work->list); } spin_unlock_bh(&wb->work_lock); - - /* - * Once we start processing a work item that had !nr_pages, - * clear the wb state bit for that so we can allow more. - */ - if (work && work->start_all) - clear_bit(WB_start_all, &wb->state); - return work; } @@ -1901,6 +1869,30 @@ static long wb_check_old_data_flush(struct bdi_writeback *wb) return 0; } +static long wb_check_start_all(struct bdi_writeback *wb) +{ + long nr_pages; + + if (!test_bit(WB_start_all, &wb->state)) + return 0; + + nr_pages = get_nr_dirty_pages(); + if (nr_pages) { + struct wb_writeback_work work = { + .nr_pages = wb_split_bdi_pages(wb, nr_pages), + .sync_mode = WB_SYNC_NONE, + .range_cyclic = 1, + .reason = wb->start_all_reason, + }; + + nr_pages = wb_writeback(wb, &work); + } + + clear_bit(WB_start_all, &wb->state); + return nr_pages; +} + + /* * Retrieve work items and do the writeback they describe */ @@ -1916,6 +1908,11 @@ static long wb_do_writeback(struct bdi_writeback *wb) finish_writeback_work(wb, work); } + /* + * Check for a flush-everything request + */ + wrote += wb_check_start_all(wb); + /* * Check for periodic writeback, kupdated() style */ diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index 420de5c7c7f9..b7c7be6f5986 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -44,6 +44,28 @@ enum wb_stat_item { #define WB_STAT_BATCH (8*(1+ilog2(nr_cpu_ids))) +/* + * why some writeback work was initiated + */ +enum wb_reason { + WB_REASON_BACKGROUND, + WB_REASON_VMSCAN, + WB_REASON_SYNC, + WB_REASON_PERIODIC, + WB_REASON_LAPTOP_TIMER, + WB_REASON_FREE_MORE_MEM, + WB_REASON_FS_FREE_SPACE, + /* + * There is no bdi forker thread any more and works are done + * by emergency worker, however, this is TPs userland visible + * and we'll be exposing exactly the same information, + * so it has a mismatch name. + */ + WB_REASON_FORKER_THREAD, + + WB_REASON_MAX, +}; + /* * For cgroup writeback, multiple wb's may map to the same blkcg. Those * wb's can operate mostly independently but should share the congested @@ -116,6 +138,7 @@ struct bdi_writeback { struct fprop_local_percpu completions; int dirty_exceeded; + enum wb_reason start_all_reason; spinlock_t work_lock; /* protects work_list & dwork scheduling */ struct list_head work_list; diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 9c0091678af4..dd1d2c23f743 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -41,28 +41,6 @@ enum writeback_sync_modes { WB_SYNC_ALL, /* Wait on every mapping */ }; -/* - * why some writeback work was initiated - */ -enum wb_reason { - WB_REASON_BACKGROUND, - WB_REASON_VMSCAN, - WB_REASON_SYNC, - WB_REASON_PERIODIC, - WB_REASON_LAPTOP_TIMER, - WB_REASON_FREE_MORE_MEM, - WB_REASON_FS_FREE_SPACE, - /* - * There is no bdi forker thread any more and works are done - * by emergency worker, however, this is TPs userland visible - * and we'll be exposing exactly the same information, - * so it has a mismatch name. - */ - WB_REASON_FORKER_THREAD, - - WB_REASON_MAX, -}; - /* * A control structure which tells the writeback code what to do. These are * always on the stack, and hence need no locking. They are always initialised diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index 9b57f014d79d..19a0ea08e098 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -286,7 +286,6 @@ DEFINE_EVENT(writeback_class, name, \ TP_PROTO(struct bdi_writeback *wb), \ TP_ARGS(wb)) -DEFINE_WRITEBACK_EVENT(writeback_nowork); DEFINE_WRITEBACK_EVENT(writeback_wake_background); TRACE_EVENT(writeback_bdi_register, -- cgit v1.2.3 From 8264c3214f28b52b399d9e03bfa7feec275a0d71 Mon Sep 17 00:00:00 2001 From: Rakesh Pandit Date: Mon, 9 Oct 2017 13:34:41 +0300 Subject: writeback: merge try_to_writeback_inodes_sb_nr() into caller Since commit 925a6efb8ff0c ("Btrfs: stop using try_to_writeback_inodes_sb_nr to flush delalloc") this function hasn't been used outside so stop exporting it. In addition we merge it into try_to_writeback_inodes_sb() which is the only caller. Also change return type of try_to_writeback_inodes_sb to void as the only user ext4 doesn't care. Reviewed-by: Jan Kara Signed-off-by: Rakesh Pandit Signed-off-by: Jens Axboe --- fs/fs-writeback.c | 30 ++++++------------------------ include/linux/writeback.h | 4 +--- 2 files changed, 7 insertions(+), 27 deletions(-) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 9e24d604c59c..08f5debd07d1 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -2376,37 +2376,19 @@ void writeback_inodes_sb(struct super_block *sb, enum wb_reason reason) EXPORT_SYMBOL(writeback_inodes_sb); /** - * try_to_writeback_inodes_sb_nr - try to start writeback if none underway + * try_to_writeback_inodes_sb - try to start writeback if none underway * @sb: the superblock - * @nr: the number of pages to write - * @reason: the reason of writeback + * @reason: reason why some writeback work was initiated * - * Invoke writeback_inodes_sb_nr if no writeback is currently underway. - * Returns 1 if writeback was started, 0 if not. + * Invoke __writeback_inodes_sb_nr if no writeback is currently underway. */ -bool try_to_writeback_inodes_sb_nr(struct super_block *sb, unsigned long nr, - enum wb_reason reason) +void try_to_writeback_inodes_sb(struct super_block *sb, enum wb_reason reason) { if (!down_read_trylock(&sb->s_umount)) - return false; + return; - __writeback_inodes_sb_nr(sb, nr, reason, true); + __writeback_inodes_sb_nr(sb, get_nr_dirty_pages(), reason, true); up_read(&sb->s_umount); - return true; -} -EXPORT_SYMBOL(try_to_writeback_inodes_sb_nr); - -/** - * try_to_writeback_inodes_sb - try to start writeback if none underway - * @sb: the superblock - * @reason: reason why some writeback work was initiated - * - * Implement by try_to_writeback_inodes_sb_nr() - * Returns 1 if writeback was started, 0 if not. - */ -bool try_to_writeback_inodes_sb(struct super_block *sb, enum wb_reason reason) -{ - return try_to_writeback_inodes_sb_nr(sb, get_nr_dirty_pages(), reason); } EXPORT_SYMBOL(try_to_writeback_inodes_sb); diff --git a/include/linux/writeback.h b/include/linux/writeback.h index dd1d2c23f743..e15ec14085ad 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -163,9 +163,7 @@ struct bdi_writeback; void writeback_inodes_sb(struct super_block *, enum wb_reason reason); void writeback_inodes_sb_nr(struct super_block *, unsigned long nr, enum wb_reason reason); -bool try_to_writeback_inodes_sb(struct super_block *, enum wb_reason reason); -bool try_to_writeback_inodes_sb_nr(struct super_block *, unsigned long nr, - enum wb_reason reason); +void try_to_writeback_inodes_sb(struct super_block *sb, enum wb_reason reason); void sync_inodes_sb(struct super_block *); void wakeup_flusher_threads(enum wb_reason reason); void wakeup_flusher_threads_bdi(struct backing_dev_info *bdi, -- cgit v1.2.3