Change long from v1:
o add description
o change the # of batched segments suggested by Chao
o make consistent for # of batched segments
This patch introduces a batched trimming feature, which submits split discard
commands.
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.
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/f2fs.h | 2 ++
fs/f2fs/segment.c | 16 +++++++++++-----
2 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 8231a59..ec5e66f 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -105,6 +105,8 @@ enum {
CP_DISCARD,
};
+#define BATCHED_TRIM_SEGMENTS(sbi) (((sbi)->segs_per_sec) << 5)
+
struct cp_control {
int reason;
__u64 trim_start;
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 5ea57ec..b85bb97 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1066,14 +1066,20 @@ int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
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 += BATCHED_TRIM_SEGMENTS(sbi)) {
+ cpc.trim_start = start_segno;
+ cpc.trim_end = min_t(unsigned int,
+ start_segno + BATCHED_TRIM_SEGMENTS (sbi) - 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;
--
2.1.1
--
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