f2fs: support subsectional garbage collection
Section is minimal garbage collection unit of f2fs, in zoned block
device, or ancient block mapping flash device, in order to improve
GC efficiency, we can align GC unit to lower device erase unit,
normally, it consists of multiple of segments.
Once background or foreground GC triggers, it brings a large number
of IOs, which will impact user IO, and also occupy cpu/memory resource
intensively.
So, to reduce impact of GC on large size section, this patch supports
subsectional GC, in one cycle of GC, it only migrate partial segment{s}
in victim section. Currently, by default, we use sbi->segs_per_sec as
migration granularity.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index c50c3aa..2e3dde8 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1263,6 +1263,7 @@ struct f2fs_sb_info {
struct f2fs_gc_kthread *gc_thread; /* GC thread */
unsigned int cur_victim_sec; /* current victim section num */
unsigned int gc_mode; /* current GC state */
+ unsigned int next_victim_seg[2]; /* next segment in victim section */
/* for skip statistic */
unsigned long long skipped_atomic_files[2]; /* FG_GC and BG_GC */
unsigned long long skipped_gc_rwsem; /* FG_GC only */
@@ -1272,6 +1273,8 @@ struct f2fs_sb_info {
/* maximum # of trials to find a victim segment for SSR and GC */
unsigned int max_victim_search;
+ /* migration granularity of garbage collection, unit: segment */
+ unsigned int migration_granularity;
/*
* for stat information.