BMC/Intel-BMC/linux.git/drivers/md/bcache/bcache.h, branch dev-5.3

bcache: add reclaimed_journal_buckets to struct cache_set

2019-06-28T13:39:18+00:00

Now we have counters for how many times jouranl is reclaimed, how many times cached dirty btree nodes are flushed, but we don't know how many jouranl buckets are really reclaimed. This patch adds reclaimed_journal_buckets into struct cache_set, this is an increasing only counter, to tell how many journal buckets are reclaimed since cache set runs. From all these three counters (reclaim, reclaimed_journal_buckets, flush_write), we can have idea how well current journal space reclaim code works. Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: remove retry_flush_write from struct cache_set

2019-06-28T13:39:18+00:00

In struct cache_set, retry_flush_write is added for commit c4dc2497d50d ("bcache: fix high CPU occupancy during journal") which is reverted in previous patch. Now it is useless anymore, and this patch removes it from bcache code. Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: Revert "bcache: fix high CPU occupancy during journal"

2019-06-28T13:39:17+00:00

This reverts commit c4dc2497d50d9c6fb16aa0d07b6a14f3b2adb1e0. This patch enlarges a race between normal btree flush code path and flush_btree_write(), which causes deadlock when journal space is exhausted. Reverts this patch makes the race window from 128 btree nodes to only 1 btree nodes. Fixes: c4dc2497d50d ("bcache: fix high CPU occupancy during journal") Signed-off-by: Coly Li Cc: stable@vger.kernel.org Cc: Tang Junhui Signed-off-by: Jens Axboe

bcache: add return value check to bch_cached_dev_run()

2019-06-28T13:39:14+00:00

This patch adds return value check to bch_cached_dev_run(), now if there is error happens inside bch_cached_dev_run(), it can be catched. Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: option to automatically run gc thread after writeback

2018-12-13T15:15:54+00:00

The option gc_after_writeback is disabled by default, because garbage collection will discard SSD data which drops cached data. Echo 1 into /sys/fs/bcache//internal/gc_after_writeback will enable this option, which wakes up gc thread when writeback accomplished and all cached data is clean. This option is helpful for people who cares writing performance more. In heavy writing workload, all cached data can be clean only happens when writeback thread cleans all cached data in I/O idle time. In such situation a following gc running may help to shrink bcache B+ tree and discard more clean data, which may be helpful for future writing requests. If you are not sure whether this is helpful for your own workload, please leave it as disabled by default. Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: add comment for cache_set->fill_iter

2018-12-13T15:15:54+00:00

We have the following define for btree iterator: struct btree_iter { size_t size, used; #ifdef CONFIG_BCACHE_DEBUG struct btree_keys *b; #endif struct btree_iter_set { struct bkey *k, *end; } data[MAX_BSETS]; }; We can see that the length of data[] field is static MAX_BSETS, which is defined as 4 currently. But a btree node on disk could have too many bsets for an iterator to fit on the stack - maybe far more that MAX_BSETS. Have to dynamically allocate space to host more btree_iter_sets. bch_cache_set_alloc() will make sure the pool cache_set->fill_iter can allocate an iterator equipped with enough room that can host (sb.bucket_size / sb.block_size) btree_iter_sets, which is more than static MAX_BSETS. bch_btree_node_read_done() will use that pool to allocate one iterator, to host many bsets in one btree node. Add more comment around cache_set->fill_iter to make code less confusing. Signed-off-by: Shenghui Wang Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: remove useless parameter of bch_debug_init()

2018-10-08T14:19:53+00:00

Parameter "struct kobject *kobj" in bch_debug_init() is useless, remove it in this patch. Signed-off-by: Dongbo Cao Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: add separate workqueue for journal_write to avoid deadlock

2018-09-27T15:47:01+00:00

After write SSD completed, bcache schedules journal_write work to system_wq, which is a public workqueue in system, without WQ_MEM_RECLAIM flag. system_wq is also a bound wq, and there may be no idle kworker on current processor. Creating a new kworker may unfortunately need to reclaim memory first, by shrinking cache and slab used by vfs, which depends on bcache device. That's a deadlock. This patch create a new workqueue for journal_write with WQ_MEM_RECLAIM flag. It's rescuer thread will work to avoid the deadlock. Signed-off-by: Guoju Fang Cc: stable@vger.kernel.org Signed-off-by: Coly Li Signed-off-by: Jens Axboe

bcache: remove unnecessary space before ioctl function pointer arguments

2018-08-11T21:46:42+00:00

This is warned by checkpatch.pl, this patch removes the extra space. Signed-off-by: Coly Li Reviewed-by: Shenghui Wang Signed-off-by: Jens Axboe

bcache: replace Symbolic permissions by octal permission numbers

2018-08-11T21:46:41+00:00

Symbolic permission names are used in bcache, for now octal permission numbers are encouraged to use for readability. This patch replaces all symbolic permissions by octal permission numbers. Signed-off-by: Coly Li Reviewed-by: Shenghui Wang Signed-off-by: Jens Axboe