f2fs: add missing description for ipu_policy node

IPU policy can be disabled, let's add description for it and other policy.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Yangtao Li 2023-02-06 22:43:09 +08:00 committed by Jaegeuk Kim
parent c5bf834833
commit 9e615dbba4

View file

@ -49,16 +49,23 @@ Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
Description: Controls the in-place-update policy.
updates in f2fs. User can set:
==== =================
0x01 F2FS_IPU_FORCE
0x02 F2FS_IPU_SSR
0x04 F2FS_IPU_UTIL
0x08 F2FS_IPU_SSR_UTIL
0x10 F2FS_IPU_FSYNC
0x20 F2FS_IPU_ASYNC
0x40 F2FS_IPU_NOCACHE
0x80 F2FS_IPU_HONOR_OPU_WRITE
==== =================
===== =============== ===================================================
value policy description
0x00 DISABLE disable IPU(=default option in LFS mode)
0x01 FORCE all the time
0x02 SSR if SSR mode is activated
0x04 UTIL if FS utilization is over threashold
0x08 SSR_UTIL if SSR mode is activated and FS utilization is over
threashold
0x10 FSYNC activated in fsync path only for high performance
flash storages. IPU will be triggered only if the
# of dirty pages over min_fsync_blocks.
(=default option)
0x20 ASYNC do IPU given by asynchronous write requests
0x40 NOCACHE disable IPU bio cache
0x80 HONOR_OPU_WRITE use OPU write prior to IPU write if inode has
FI_OPU_WRITE flag
===== =============== ===================================================
Refer segment.h for details.