f2fs: introduce a batched trim
This patch introduces a batched trimming feature, which submits split discard
commands.
This is to avoid long latency due to huge trim commands.
If fstrim was triggered ranging from 0 to the end of device, we should lock
all the checkpoint-related mutexes, resulting in very long latency.
Reviewed-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 5ea57ec..9f278d1 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1066,14 +1066,19 @@
end_segno = (end >= MAX_BLKADDR(sbi)) ? MAIN_SEGS(sbi) - 1 :
GET_SEGNO(sbi, end);
cpc.reason = CP_DISCARD;
- cpc.trim_start = start_segno;
- cpc.trim_end = end_segno;
cpc.trim_minlen = range->minlen >> sbi->log_blocksize;
/* do checkpoint to issue discard commands safely */
- mutex_lock(&sbi->gc_mutex);
- write_checkpoint(sbi, &cpc);
- mutex_unlock(&sbi->gc_mutex);
+ for (; start_segno <= end_segno; start_segno = cpc.trim_end + 1) {
+ cpc.trim_start = start_segno;
+ cpc.trim_end = min_t(unsigned int, rounddown(start_segno +
+ BATCHED_TRIM_SEGMENTS(sbi),
+ sbi->segs_per_sec) - 1, end_segno);
+
+ mutex_lock(&sbi->gc_mutex);
+ write_checkpoint(sbi, &cpc);
+ mutex_unlock(&sbi->gc_mutex);
+ }
out:
range->len = cpc.trimmed << sbi->log_blocksize;
return 0;
@@ -2127,6 +2132,8 @@
sm_info->nr_discards = 0;
sm_info->max_discards = 0;
+ sm_info->trim_sections = DEF_BATCHED_TRIM_SECTIONS;
+
INIT_LIST_HEAD(&sm_info->sit_entry_set);
if (test_opt(sbi, FLUSH_MERGE) && !f2fs_readonly(sbi->sb)) {
