f2fs: add a sysfs entry to control max_discards (7ac8c3b0) · Commits · 戴 / test

If frequent small discards are issued to the device, the performance would be degraded significantly. So, this patch adds a sysfs entry to control the number of discards to be issued during a checkpoint procedure. By default, f2fs does not issue any small discards, which means max_discards is zero. Signed-off-by:

Jaegeuk Kim <jaegeuk.kim@samsung.com>

fs/f2fs/super.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -175,6 +175,7 @@ F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_max_sleep_time, max_sleep_time);
		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);

		#define ATTR_LIST(name) (&f2fs_attr_##name.attr)
		static struct attribute *f2fs_attrs[] = {
		@@ -183,6 +184,7 @@ static struct attribute *f2fs_attrs[] = {
		ATTR_LIST(gc_no_gc_sleep_time),
		ATTR_LIST(gc_idle),
		ATTR_LIST(reclaim_segments),
		ATTR_LIST(max_small_discards),
		NULL,
		};

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