Commit b2e4a2b3 authored by Konstantin Vyshetsky's avatar Konstantin Vyshetsky Committed by Jaegeuk Kim
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f2fs: expose discard related parameters in sysfs 



This patch exposes max_discard_request, min_discard_issue_time,
mid_discard_issue_time, and max_discard_issue_time in sysfs. This will
allow the user to fine tune discard operations.

Signed-off-by: default avatarKonstantin Vyshetsky <vkon@google.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent d2d8e896

Documentation/ABI/testing/sysfs-fs-f2fs

+27 −0
Original line number Diff line number Diff line
@@ -98,6 +98,33 @@ Description: Controls the issue rate of discard commands that consist of small 
		checkpoint is triggered, and issued during the checkpoint.

		By default, it is disabled with 0.



What:		/sys/fs/f2fs/<disk>/max_discard_request

Date:		December 2021

Contact:	"Konstantin Vyshetsky" <vkon@google.com>

Description:	Controls the number of discards a thread will issue at a time.

		Higher number will allow the discard thread to finish its work

		faster, at the cost of higher latency for incomming I/O.



What:		/sys/fs/f2fs/<disk>/min_discard_issue_time

Date:		December 2021

Contact:	"Konstantin Vyshetsky" <vkon@google.com>

Description:	Controls the interval the discard thread will wait between

		issuing discard requests when there are discards to be issued and

		no I/O aware interruptions occur.



What:		/sys/fs/f2fs/<disk>/mid_discard_issue_time

Date:		December 2021

Contact:	"Konstantin Vyshetsky" <vkon@google.com>

Description:	Controls the interval the discard thread will wait between

		issuing discard requests when there are discards to be issued and

		an I/O aware interruption occurs.



What:		/sys/fs/f2fs/<disk>/max_discard_issue_time

Date:		December 2021

Contact:	"Konstantin Vyshetsky" <vkon@google.com>

Description:	Controls the interval the discard thread will wait when there are

		no discard operations to be issued.



What:		/sys/fs/f2fs/<disk>/discard_granularity

Date:		July 2017

Contact:	"Chao Yu" <yuchao0@huawei.com>

fs/f2fs/sysfs.c

+8 −0
Original line number Diff line number Diff line
@@ -716,6 +716,10 @@ F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_idle, gc_mode); 
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_urgent, gc_mode);

F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);

F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, max_small_discards, max_discards);

F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, max_discard_request, max_discard_request);

F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, min_discard_issue_time, min_discard_issue_time);

F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, mid_discard_issue_time, mid_discard_issue_time);

F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, max_discard_issue_time, max_discard_issue_time);

F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, discard_granularity, discard_granularity);

F2FS_RW_ATTR(RESERVED_BLOCKS, f2fs_sb_info, reserved_blocks, reserved_blocks);

F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, batched_trim_sections, trim_sections);
@@ -832,6 +836,10 @@ static struct attribute *f2fs_attrs[] = { 
	ATTR_LIST(reclaim_segments),

	ATTR_LIST(main_blkaddr),

	ATTR_LIST(max_small_discards),

	ATTR_LIST(max_discard_request),

	ATTR_LIST(min_discard_issue_time),

	ATTR_LIST(mid_discard_issue_time),

	ATTR_LIST(max_discard_issue_time),

	ATTR_LIST(discard_granularity),

	ATTR_LIST(pending_discard),

	ATTR_LIST(batched_trim_sections),