From 3af3d772f7216cf23081bb4176e86f1219d32ebc Mon Sep 17 00:00:00 2001 From: "zhangyi (F)" Date: Sat, 13 Mar 2021 11:01:45 +0800 Subject: block_dump: remove block_dump feature We have already delete block_dump feature in mark_inode_dirty() because it can be replaced by tracepoints, now we also remove the part in submit_bio() for the same reason. The part of block dump feature in submit_bio() dump the write process, write region and sectors on the target disk into kernel message. it can be replaced by block_bio_queue tracepoint in submit_bio_checks(), so we do not need block_dump anymore, remove the whole block_dump feature. Signed-off-by: zhangyi (F) Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20210313030146.2882027-3-yi.zhang@huawei.com Signed-off-by: Jens Axboe --- include/linux/writeback.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/writeback.h') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 8e5c5bb16e2d..9ef50176f3a1 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -360,7 +360,6 @@ extern unsigned int dirty_writeback_interval; extern unsigned int dirty_expire_interval; extern unsigned int dirtytime_expire_interval; extern int vm_highmem_is_dirtyable; -extern int block_dump; extern int laptop_mode; int dirty_background_ratio_handler(struct ctl_table *table, int write, -- cgit v1.2.3 From c22d70a162d3cc177282c4487be4d54876ca55c8 Mon Sep 17 00:00:00 2001 From: Roman Gushchin Date: Mon, 28 Jun 2021 19:36:03 -0700 Subject: writeback, cgroup: release dying cgwbs by switching attached inodes Asynchronously try to release dying cgwbs by switching attached inodes to the nearest living ancestor wb. It helps to get rid of per-cgroup writeback structures themselves and of pinned memory and block cgroups, which are significantly larger structures (mostly due to large per-cpu statistics data). This prevents memory waste and helps to avoid different scalability problems caused by large piles of dying cgroups. Reuse the existing mechanism of inode switching used for foreign inode detection. To speed things up batch up to 115 inode switching in a single operation (the maximum number is selected so that the resulting struct inode_switch_wbs_context can fit into 1024 bytes). Because every switching consists of two steps divided by an RCU grace period, it would be too slow without batching. Please note that the whole batch counts as a single operation (when increasing/decreasing isw_nr_in_flight). This allows to keep umounting working (flush the switching queue), however prevents cleanups from consuming the whole switching quota and effectively blocking the frn switching. A cgwb cleanup operation can fail due to different reasons (e.g. not enough memory, the cgwb has an in-flight/pending io, an attached inode in a wrong state, etc). In this case the next scheduled cleanup will make a new attempt. An attempt is made each time a new cgwb is offlined (in other words a memcg and/or a blkcg is deleted by a user). In the future an additional attempt scheduled by a timer can be implemented. [guro@fb.com: replace open-coded "115" with arithmetic] Link: https://lkml.kernel.org/r/YMEcSBcq/VXMiPPO@carbon.dhcp.thefacebook.com [guro@fb.com: add smp_mb() to inode_prepare_wbs_switch()] Link: https://lkml.kernel.org/r/YMFa+guFw7OFjf3X@carbon.dhcp.thefacebook.com [willy@infradead.org: fix documentation] Link: https://lkml.kernel.org/r/20210615200242.1716568-2-willy@infradead.org Link: https://lkml.kernel.org/r/20210608230225.2078447-9-guro@fb.com Signed-off-by: Roman Gushchin Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Tejun Heo Acked-by: Dennis Zhou Reviewed-by: Jan Kara Cc: Alexander Viro Cc: Dave Chinner Cc: Jan Kara Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/writeback.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/writeback.h') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 8e5c5bb16e2d..95de51c10248 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -221,6 +221,7 @@ void wbc_account_cgroup_owner(struct writeback_control *wbc, struct page *page, int cgroup_writeback_by_id(u64 bdi_id, int memcg_id, unsigned long nr_pages, enum wb_reason reason, struct wb_completion *done); void cgroup_writeback_umount(void); +bool cleanup_offline_cgwb(struct bdi_writeback *wb); /** * inode_attach_wb - associate an inode with its wb -- cgit v1.2.3 From 99d26de2f6d79badc80f55b54bd90d4cb9d1ad90 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 10 Aug 2021 14:39:24 +0200 Subject: writeback: make the laptop_mode prototypes available unconditionally Fix the !CONFIG_BLOCK build after the recent cleanup. Fixes: 5ed964f8e54e ("mm: hide laptop_mode_wb_timer entirely behind the BDI API") Reported-by: Stephen Rothwell Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- include/linux/writeback.h | 5 ----- 1 file changed, 5 deletions(-) (limited to 'include/linux/writeback.h') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 667e86cfbdcf..270677dc4f36 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -336,14 +336,9 @@ static inline void cgroup_writeback_umount(void) /* * mm/page-writeback.c */ -#ifdef CONFIG_BLOCK void laptop_io_completion(struct backing_dev_info *info); void laptop_sync_completion(void); -void laptop_mode_sync(struct work_struct *work); void laptop_mode_timer_fn(struct timer_list *t); -#else -static inline void laptop_sync_completion(void) { } -#endif bool node_dirty_ok(struct pglist_data *pgdat); int wb_domain_init(struct wb_domain *dom, gfp_t gfp); #ifdef CONFIG_CGROUP_WRITEBACK -- cgit v1.2.3 From fee468fdf41cdf36ba6b5a780e2474d0a3e066ac Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 2 Sep 2021 14:53:06 -0700 Subject: writeback: reliably update bandwidth estimation Currently we trigger writeback bandwidth estimation from balance_dirty_pages() and from wb_writeback(). However neither of these need to trigger when the system is relatively idle and writeback is triggered e.g. from fsync(2). Make sure writeback estimates happen reliably by triggering them from do_writepages(). Link: https://lkml.kernel.org/r/20210713104716.22868-2-jack@suse.cz Signed-off-by: Jan Kara Cc: Michael Stapelberg Cc: Wu Fengguang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/writeback.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/writeback.h') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 667e86cfbdcf..2480322c06a7 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -379,7 +379,6 @@ int dirty_writeback_centisecs_handler(struct ctl_table *table, int write, void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty); unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh); -void wb_update_bandwidth(struct bdi_writeback *wb, unsigned long start_time); void balance_dirty_pages_ratelimited(struct address_space *mapping); bool wb_over_bg_thresh(struct bdi_writeback *wb); -- cgit v1.2.3 From 45a2966fd64147518dc5bca25f447bd0fb5359ac Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 2 Sep 2021 14:53:09 -0700 Subject: writeback: fix bandwidth estimate for spiky workload Michael Stapelberg has reported that for workload with short big spikes of writes (GCC linker seem to trigger this frequently) the write throughput is heavily underestimated and tends to steadily sink until it reaches zero. This has rather bad impact on writeback throttling (causing stalls). The problem is that writeback throughput estimate gets updated at most once per 200 ms. One update happens early after we submit pages for writeback (at that point writeout of only small fraction of pages is completed and thus observed throughput is tiny). Next update happens only during the next write spike (updates happen only from inode writeback and dirty throttling code) and if that is more than 1s after previous spike, we decide system was idle and just ignore whatever was written until this moment. Fix the problem by making sure writeback throughput estimate is also updated shortly after writeback completes to get reasonable estimate of throughput for spiky workloads. [jack@suse.cz: avoid division by 0 in wb_update_dirty_ratelimit()] Link: https://lore.kernel.org/lkml/20210617095309.3542373-1-stapelberg+linux@google.com Link: https://lkml.kernel.org/r/20210713104716.22868-3-jack@suse.cz Signed-off-by: Jan Kara Reported-by: Michael Stapelberg Tested-by: Michael Stapelberg Cc: Wu Fengguang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/writeback.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/writeback.h') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 2480322c06a7..cbaef099645e 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -379,6 +379,7 @@ int dirty_writeback_centisecs_handler(struct ctl_table *table, int write, void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty); unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh); +void wb_update_bandwidth(struct bdi_writeback *wb); void balance_dirty_pages_ratelimited(struct address_space *mapping); bool wb_over_bg_thresh(struct bdi_writeback *wb); -- cgit v1.2.3 From 7490a2d248145d8694e1e9828801b496250fd697 Mon Sep 17 00:00:00 2001 From: Shakeel Butt Date: Thu, 2 Sep 2021 14:53:27 -0700 Subject: writeback: memcg: simplify cgroup_writeback_by_id Currently cgroup_writeback_by_id calls mem_cgroup_wb_stats() to get dirty pages for a memcg. However mem_cgroup_wb_stats() does a lot more than just get the number of dirty pages. Just directly get the number of dirty pages instead of calling mem_cgroup_wb_stats(). Also cgroup_writeback_by_id() is only called for best-effort dirty flushing, so remove the unused 'nr' parameter and no need to explicitly flush memcg stats. Link: https://lkml.kernel.org/r/20210722182627.2267368-1-shakeelb@google.com Signed-off-by: Shakeel Butt Reviewed-by: Jan Kara Cc: Tejun Heo Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/writeback.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/writeback.h') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index cbaef099645e..aeda2c0c9986 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -218,7 +218,7 @@ void wbc_attach_and_unlock_inode(struct writeback_control *wbc, void wbc_detach_inode(struct writeback_control *wbc); void wbc_account_cgroup_owner(struct writeback_control *wbc, struct page *page, size_t bytes); -int cgroup_writeback_by_id(u64 bdi_id, int memcg_id, unsigned long nr_pages, +int cgroup_writeback_by_id(u64 bdi_id, int memcg_id, enum wb_reason reason, struct wb_completion *done); void cgroup_writeback_umount(void); bool cleanup_offline_cgwb(struct bdi_writeback *wb); -- cgit v1.2.3