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f2fs: introduce a batched trim

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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 <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Jaegeuk Kim 2015-01-26 17:41:23 -08:00
parent 487261f39b
commit bba681cbb2
5 changed files with 31 additions and 5 deletions
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6
Documentation/ABI/testing/sysfs-fs-f2fs
View File

@ -74,3 +74,9 @@ Date: March 2014
Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
Description:
Controls the memory footprint used by f2fs.
What: /sys/fs/f2fs/<disk>/trim_sections
Date: February 2015
Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
Description:
Controls the trimming rate in batch mode.

4
Documentation/filesystems/f2fs.txt
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@ -199,6 +199,10 @@ Files in /sys/fs/f2fs/<devname>
checkpoint is triggered, and issued during the
checkpoint. By default, it is disabled with 0.
trim_sections This parameter controls the number of sections
to be trimmed out in batch mode when FITRIM
conducts. 32 sections is set by default.
ipu_policy This parameter controls the policy of in-place
updates in f2fs. There are five policies:
0x01: F2FS_IPU_FORCE, 0x02: F2FS_IPU_SSR,

7
fs/f2fs/f2fs.h
View File

@ -105,6 +105,10 @@ enum {
CP_DISCARD,
};
#define DEF_BATCHED_TRIM_SECTIONS 32
#define BATCHED_TRIM_SEGMENTS(sbi) \
(SM_I(sbi)->trim_sections * (sbi)->segs_per_sec)
struct cp_control {
int reason;
__u64 trim_start;
@ -448,6 +452,9 @@ struct f2fs_sm_info {
int nr_discards; /* # of discards in the list */
int max_discards; /* max. discards to be issued */
/* for batched trimming */
unsigned int trim_sections; /* # of sections to trim */
struct list_head sit_entry_set; /* sit entry set list */
unsigned int ipu_policy; /* in-place-update policy */

17
fs/f2fs/segment.c
View File

@ -1066,14 +1066,19 @@ 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 = 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 @@ int build_segment_manager(struct f2fs_sb_info *sbi)
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)) {

2
fs/f2fs/super.c
View File

@ -195,6 +195,7 @@ F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_no_gc_sleep_time, no_gc_sleep_time);
F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_idle, gc_idle);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, max_small_discards, max_discards);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, batched_trim_sections, trim_sections);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util);
F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_fsync_blocks, min_fsync_blocks);
@ -210,6 +211,7 @@ static struct attribute *f2fs_attrs[] = {
ATTR_LIST(gc_idle),
ATTR_LIST(reclaim_segments),
ATTR_LIST(max_small_discards),
ATTR_LIST(batched_trim_sections),
ATTR_LIST(ipu_policy),
ATTR_LIST(min_ipu_util),
ATTR_LIST(min_fsync_blocks),