@@ -763,3 +763,11 @@ Date: November 2023
Contact: "Chao Yu" <chao@kernel.org>
Description: It controls to enable/disable IO aware feature for background discard.
By default, the value is 1 which indicates IO aware is on.
+
+What: /sys/fs/f2fs/<disk>/migration_window_granularity
+Date: September 2024
+Contact: "Daeho Jeong" <daehojeong@google.com>
+Description: Controls migration window granularity of garbage collection on large
+ section. it can control the scanning window granularity for GC migration
+ in a unit of segment, while migration_granularity controls the number
+ of segments which can be migrated at the same turn.
@@ -1685,6 +1685,8 @@ struct f2fs_sb_info {
unsigned int max_victim_search;
/* migration granularity of garbage collection, unit: segment */
unsigned int migration_granularity;
+ /* migration window granularity of garbage collection, unit: segment */
+ unsigned int migration_window_granularity;
/*
* for stat information.
@@ -1708,24 +1708,34 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
struct blk_plug plug;
unsigned int segno = start_segno;
unsigned int end_segno = start_segno + SEGS_PER_SEC(sbi);
+ unsigned int sec_end_segno;
int seg_freed = 0, migrated = 0;
unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
SUM_TYPE_DATA : SUM_TYPE_NODE;
unsigned char data_type = (type == SUM_TYPE_DATA) ? DATA : NODE;
int submitted = 0;
- if (__is_large_section(sbi))
- end_segno = rounddown(end_segno, SEGS_PER_SEC(sbi));
+ if (__is_large_section(sbi)) {
+ sec_end_segno = rounddown(end_segno, SEGS_PER_SEC(sbi));
- /*
- * zone-capacity can be less than zone-size in zoned devices,
- * resulting in less than expected usable segments in the zone,
- * calculate the end segno in the zone which can be garbage collected
- */
- if (f2fs_sb_has_blkzoned(sbi))
- end_segno -= SEGS_PER_SEC(sbi) -
+ /*
+ * zone-capacity can be less than zone-size in zoned devices,
+ * resulting in less than expected usable segments in the zone,
+ * calculate the end segno in the zone which can be garbage
+ * collected
+ */
+ if (f2fs_sb_has_blkzoned(sbi))
+ sec_end_segno -= SEGS_PER_SEC(sbi) -
f2fs_usable_segs_in_sec(sbi, segno);
+ if (gc_type == BG_GC)
+ end_segno = start_segno +
+ sbi->migration_window_granularity;
+
+ if (end_segno > sec_end_segno)
+ end_segno = sec_end_segno;
+ }
+
sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
/* readahead multi ssa blocks those have contiguous address */
@@ -1803,7 +1813,8 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
if (__is_large_section(sbi))
sbi->next_victim_seg[gc_type] =
- (segno + 1 < end_segno) ? segno + 1 : NULL_SEGNO;
+ (segno + 1 < sec_end_segno) ?
+ segno + 1 : NULL_SEGNO;
skip:
f2fs_put_page(sum_page, 0);
}
@@ -32,6 +32,7 @@
#define LIMIT_NO_ZONED_GC 60 /* percentage over total user space of no gc for zoned devices */
#define LIMIT_BOOST_ZONED_GC 25 /* percentage over total user space of boosted gc for zoned devices */
+#define DEF_MIGRATION_WINDOW_GRANULARITY_ZONED 3
#define DEF_GC_FAILED_PINNED_FILES 2048
#define MAX_GC_FAILED_PINNED_FILES USHRT_MAX
@@ -3791,6 +3791,8 @@ static void init_sb_info(struct f2fs_sb_info *sbi)
sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
sbi->max_victim_search = DEF_MAX_VICTIM_SEARCH;
sbi->migration_granularity = SEGS_PER_SEC(sbi);
+ sbi->migration_window_granularity = f2fs_sb_has_blkzoned(sbi) ?
+ DEF_MIGRATION_WINDOW_GRANULARITY_ZONED : SEGS_PER_SEC(sbi);
sbi->seq_file_ra_mul = MIN_RA_MUL;
sbi->max_fragment_chunk = DEF_FRAGMENT_SIZE;
sbi->max_fragment_hole = DEF_FRAGMENT_SIZE;
@@ -561,6 +561,11 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
return -EINVAL;
}
+ if (!strcmp(a->attr.name, "migration_window_granularity")) {
+ if (t == 0 || t > SEGS_PER_SEC(sbi))
+ return -EINVAL;
+ }
+
if (!strcmp(a->attr.name, "gc_urgent")) {
if (t == 0) {
sbi->gc_mode = GC_NORMAL;
@@ -1001,6 +1006,7 @@ F2FS_SBI_RW_ATTR(gc_pin_file_thresh, gc_pin_file_threshold);
F2FS_SBI_RW_ATTR(gc_reclaimed_segments, gc_reclaimed_segs);
F2FS_SBI_GENERAL_RW_ATTR(max_victim_search);
F2FS_SBI_GENERAL_RW_ATTR(migration_granularity);
+F2FS_SBI_GENERAL_RW_ATTR(migration_window_granularity);
F2FS_SBI_GENERAL_RW_ATTR(dir_level);
#ifdef CONFIG_F2FS_IOSTAT
F2FS_SBI_GENERAL_RW_ATTR(iostat_enable);
@@ -1140,6 +1146,7 @@ static struct attribute *f2fs_attrs[] = {
ATTR_LIST(min_ssr_sections),
ATTR_LIST(max_victim_search),
ATTR_LIST(migration_granularity),
+ ATTR_LIST(migration_window_granularity),
ATTR_LIST(dir_level),
ATTR_LIST(ram_thresh),
ATTR_LIST(ra_nid_pages),