sysfs-fs-f2fs 20 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514
  1. What: /sys/fs/f2fs/<disk>/gc_max_sleep_time
  2. Date: July 2013
  3. Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
  4. Description: Controls the maximum sleep time for gc_thread. Time
  5. is in milliseconds.
  6. What: /sys/fs/f2fs/<disk>/gc_min_sleep_time
  7. Date: July 2013
  8. Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
  9. Description: Controls the minimum sleep time for gc_thread. Time
  10. is in milliseconds.
  11. What: /sys/fs/f2fs/<disk>/gc_no_gc_sleep_time
  12. Date: July 2013
  13. Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
  14. Description: Controls the default sleep time for gc_thread. Time
  15. is in milliseconds.
  16. What: /sys/fs/f2fs/<disk>/gc_idle
  17. Date: July 2013
  18. Contact: "Namjae Jeon" <namjae.jeon@samsung.com>
  19. Description: Controls the victim selection policy for garbage collection.
  20. Setting gc_idle = 0(default) will disable this option. Setting:
  21. =========== ===============================================
  22. gc_idle = 1 will select the Cost Benefit approach & setting
  23. gc_idle = 2 will select the greedy approach & setting
  24. gc_idle = 3 will select the age-threshold based approach.
  25. =========== ===============================================
  26. What: /sys/fs/f2fs/<disk>/reclaim_segments
  27. Date: October 2013
  28. Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
  29. Description: This parameter controls the number of prefree segments to be
  30. reclaimed. If the number of prefree segments is larger than
  31. the number of segments in the proportion to the percentage
  32. over total volume size, f2fs tries to conduct checkpoint to
  33. reclaim the prefree segments to free segments.
  34. By default, 5% over total # of segments.
  35. What: /sys/fs/f2fs/<disk>/main_blkaddr
  36. Date: November 2019
  37. Contact: "Ramon Pantin" <pantin@google.com>
  38. Description:
  39. Shows first block address of MAIN area.
  40. What: /sys/fs/f2fs/<disk>/ipu_policy
  41. Date: November 2013
  42. Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
  43. Description: Controls the in-place-update policy.
  44. updates in f2fs. User can set:
  45. ==== =================
  46. 0x01 F2FS_IPU_FORCE
  47. 0x02 F2FS_IPU_SSR
  48. 0x04 F2FS_IPU_UTIL
  49. 0x08 F2FS_IPU_SSR_UTIL
  50. 0x10 F2FS_IPU_FSYNC
  51. 0x20 F2FS_IPU_ASYNC,
  52. 0x40 F2FS_IPU_NOCACHE
  53. ==== =================
  54. Refer segment.h for details.
  55. What: /sys/fs/f2fs/<disk>/min_ipu_util
  56. Date: November 2013
  57. Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
  58. Description: Controls the FS utilization condition for the in-place-update
  59. policies. It is used by F2FS_IPU_UTIL and F2FS_IPU_SSR_UTIL policies.
  60. What: /sys/fs/f2fs/<disk>/min_fsync_blocks
  61. Date: September 2014
  62. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  63. Description: Controls the dirty page count condition for the in-place-update
  64. policies.
  65. What: /sys/fs/f2fs/<disk>/min_seq_blocks
  66. Date: August 2018
  67. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  68. Description: Controls the dirty page count condition for batched sequential
  69. writes in writepages.
  70. What: /sys/fs/f2fs/<disk>/min_hot_blocks
  71. Date: March 2017
  72. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  73. Description: Controls the dirty page count condition for redefining hot data.
  74. What: /sys/fs/f2fs/<disk>/min_ssr_sections
  75. Date: October 2017
  76. Contact: "Chao Yu" <yuchao0@huawei.com>
  77. Description: Controls the free section threshold to trigger SSR allocation.
  78. If this is large, SSR mode will be enabled early.
  79. What: /sys/fs/f2fs/<disk>/max_small_discards
  80. Date: November 2013
  81. Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
  82. Description: Controls the issue rate of discard commands that consist of small
  83. blocks less than 2MB. The candidates to be discarded are cached until
  84. checkpoint is triggered, and issued during the checkpoint.
  85. By default, it is disabled with 0.
  86. What: /sys/fs/f2fs/<disk>/discard_granularity
  87. Date: July 2017
  88. Contact: "Chao Yu" <yuchao0@huawei.com>
  89. Description: Controls discard granularity of inner discard thread. Inner thread
  90. will not issue discards with size that is smaller than granularity.
  91. The unit size is one block(4KB), now only support configuring
  92. in range of [1, 512]. Default value is 4(=16KB).
  93. What: /sys/fs/f2fs/<disk>/umount_discard_timeout
  94. Date: January 2019
  95. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  96. Description: Set timeout to issue discard commands during umount.
  97. Default: 5 secs
  98. What: /sys/fs/f2fs/<disk>/pending_discard
  99. Date: November 2021
  100. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  101. Description: Shows the number of pending discard commands in the queue.
  102. What: /sys/fs/f2fs/<disk>/max_victim_search
  103. Date: January 2014
  104. Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
  105. Description: Controls the number of trials to find a victim segment
  106. when conducting SSR and cleaning operations. The default value
  107. is 4096 which covers 8GB block address range.
  108. What: /sys/fs/f2fs/<disk>/migration_granularity
  109. Date: October 2018
  110. Contact: "Chao Yu" <yuchao0@huawei.com>
  111. Description: Controls migration granularity of garbage collection on large
  112. section, it can let GC move partial segment{s} of one section
  113. in one GC cycle, so that dispersing heavy overhead GC to
  114. multiple lightweight one.
  115. What: /sys/fs/f2fs/<disk>/dir_level
  116. Date: March 2014
  117. Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
  118. Description: Controls the directory level for large directory. If a
  119. directory has a number of files, it can reduce the file lookup
  120. latency by increasing this dir_level value. Otherwise, it
  121. needs to decrease this value to reduce the space overhead.
  122. The default value is 0.
  123. What: /sys/fs/f2fs/<disk>/ram_thresh
  124. Date: March 2014
  125. Contact: "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
  126. Description: Controls the memory footprint used by free nids and cached
  127. nat entries. By default, 1 is set, which indicates
  128. 10 MB / 1 GB RAM.
  129. What: /sys/fs/f2fs/<disk>/batched_trim_sections
  130. Date: February 2015
  131. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  132. Description: Controls the trimming rate in batch mode.
  133. <deprecated>
  134. What: /sys/fs/f2fs/<disk>/cp_interval
  135. Date: October 2015
  136. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  137. Description: Controls the checkpoint timing, set to 60 seconds by default.
  138. What: /sys/fs/f2fs/<disk>/idle_interval
  139. Date: January 2016
  140. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  141. Description: Controls the idle timing of system, if there is no FS operation
  142. during given interval.
  143. Set to 5 seconds by default.
  144. What: /sys/fs/f2fs/<disk>/discard_idle_interval
  145. Date: September 2018
  146. Contact: "Chao Yu" <yuchao0@huawei.com>
  147. Contact: "Sahitya Tummala" <stummala@codeaurora.org>
  148. Description: Controls the idle timing of discard thread given
  149. this time interval.
  150. Default is 5 secs.
  151. What: /sys/fs/f2fs/<disk>/gc_idle_interval
  152. Date: September 2018
  153. Contact: "Chao Yu" <yuchao0@huawei.com>
  154. Contact: "Sahitya Tummala" <stummala@codeaurora.org>
  155. Description: Controls the idle timing for gc path. Set to 5 seconds by default.
  156. What: /sys/fs/f2fs/<disk>/iostat_enable
  157. Date: August 2017
  158. Contact: "Chao Yu" <yuchao0@huawei.com>
  159. Description: Controls to enable/disable IO stat.
  160. What: /sys/fs/f2fs/<disk>/ra_nid_pages
  161. Date: October 2015
  162. Contact: "Chao Yu" <chao2.yu@samsung.com>
  163. Description: Controls the count of nid pages to be readaheaded.
  164. When building free nids, F2FS reads NAT blocks ahead for
  165. speed up. Default is 0.
  166. What: /sys/fs/f2fs/<disk>/dirty_nats_ratio
  167. Date: January 2016
  168. Contact: "Chao Yu" <chao2.yu@samsung.com>
  169. Description: Controls dirty nat entries ratio threshold, if current
  170. ratio exceeds configured threshold, checkpoint will
  171. be triggered for flushing dirty nat entries.
  172. What: /sys/fs/f2fs/<disk>/lifetime_write_kbytes
  173. Date: January 2016
  174. Contact: "Shuoran Liu" <liushuoran@huawei.com>
  175. Description: Shows total written kbytes issued to disk.
  176. What: /sys/fs/f2fs/<disk>/features
  177. Date: July 2017
  178. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  179. Description: <deprecated: should use /sys/fs/f2fs/<disk>/feature_list/
  180. Shows all enabled features in current device.
  181. Supported features:
  182. encryption, blkzoned, extra_attr, projquota, inode_checksum,
  183. flexible_inline_xattr, quota_ino, inode_crtime, lost_found,
  184. verity, sb_checksum, casefold, readonly, compression, pin_file.
  185. What: /sys/fs/f2fs/<disk>/feature_list/
  186. Date: June 2021
  187. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  188. Description: Expand /sys/fs/f2fs/<disk>/features to meet sysfs rule.
  189. Supported on-disk features:
  190. encryption, block_zoned (aka blkzoned), extra_attr,
  191. project_quota (aka projquota), inode_checksum,
  192. flexible_inline_xattr, quota_ino, inode_crtime, lost_found,
  193. verity, sb_checksum, casefold, readonly, compression.
  194. Note that, pin_file is moved into /sys/fs/f2fs/features/.
  195. What: /sys/fs/f2fs/features/
  196. Date: July 2017
  197. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  198. Description: Shows all enabled kernel features.
  199. Supported features:
  200. encryption, block_zoned, extra_attr, project_quota,
  201. inode_checksum, flexible_inline_xattr, quota_ino,
  202. inode_crtime, lost_found, verity, sb_checksum,
  203. casefold, readonly, compression, test_dummy_encryption_v2,
  204. atomic_write, pin_file, encrypted_casefold.
  205. What: /sys/fs/f2fs/<disk>/inject_rate
  206. Date: May 2016
  207. Contact: "Sheng Yong" <shengyong1@huawei.com>
  208. Description: Controls the injection rate of arbitrary faults.
  209. What: /sys/fs/f2fs/<disk>/inject_type
  210. Date: May 2016
  211. Contact: "Sheng Yong" <shengyong1@huawei.com>
  212. Description: Controls the injection type of arbitrary faults.
  213. What: /sys/fs/f2fs/<disk>/dirty_segments
  214. Date: October 2017
  215. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  216. Description: Shows the number of dirty segments.
  217. What: /sys/fs/f2fs/<disk>/reserved_blocks
  218. Date: June 2017
  219. Contact: "Chao Yu" <yuchao0@huawei.com>
  220. Description: Controls target reserved blocks in system, the threshold
  221. is soft, it could exceed current available user space.
  222. What: /sys/fs/f2fs/<disk>/current_reserved_blocks
  223. Date: October 2017
  224. Contact: "Yunlong Song" <yunlong.song@huawei.com>
  225. Contact: "Chao Yu" <yuchao0@huawei.com>
  226. Description: Shows current reserved blocks in system, it may be temporarily
  227. smaller than target_reserved_blocks, but will gradually
  228. increase to target_reserved_blocks when more free blocks are
  229. freed by user later.
  230. What: /sys/fs/f2fs/<disk>/gc_urgent
  231. Date: August 2017
  232. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  233. Description: Do background GC agressively when set. When gc_urgent = 1,
  234. background thread starts to do GC by given gc_urgent_sleep_time
  235. interval. When gc_urgent = 2, F2FS will lower the bar of
  236. checking idle in order to process outstanding discard commands
  237. and GC a little bit aggressively. It is set to 0 by default.
  238. What: /sys/fs/f2fs/<disk>/gc_urgent_sleep_time
  239. Date: August 2017
  240. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  241. Description: Controls sleep time of GC urgent mode. Set to 500ms by default.
  242. What: /sys/fs/f2fs/<disk>/readdir_ra
  243. Date: November 2017
  244. Contact: "Sheng Yong" <shengyong1@huawei.com>
  245. Description: Controls readahead inode block in readdir. Enabled by default.
  246. What: /sys/fs/f2fs/<disk>/gc_pin_file_thresh
  247. Date: January 2018
  248. Contact: Jaegeuk Kim <jaegeuk@kernel.org>
  249. Description: This indicates how many GC can be failed for the pinned
  250. file. If it exceeds this, F2FS doesn't guarantee its pinning
  251. state. 2048 trials is set by default.
  252. What: /sys/fs/f2fs/<disk>/extension_list
  253. Date: Feburary 2018
  254. Contact: "Chao Yu" <yuchao0@huawei.com>
  255. Description: Used to control configure extension list:
  256. - Query: cat /sys/fs/f2fs/<disk>/extension_list
  257. - Add: echo '[h/c]extension' > /sys/fs/f2fs/<disk>/extension_list
  258. - Del: echo '[h/c]!extension' > /sys/fs/f2fs/<disk>/extension_list
  259. - [h] means add/del hot file extension
  260. - [c] means add/del cold file extension
  261. What: /sys/fs/f2fs/<disk>/unusable
  262. Date April 2019
  263. Contact: "Daniel Rosenberg" <drosen@google.com>
  264. Description: If checkpoint=disable, it displays the number of blocks that
  265. are unusable.
  266. If checkpoint=enable it displays the number of blocks that
  267. would be unusable if checkpoint=disable were to be set.
  268. What: /sys/fs/f2fs/<disk>/encoding
  269. Date July 2019
  270. Contact: "Daniel Rosenberg" <drosen@google.com>
  271. Description: Displays name and version of the encoding set for the filesystem.
  272. If no encoding is set, displays (none)
  273. What: /sys/fs/f2fs/<disk>/free_segments
  274. Date: September 2019
  275. Contact: "Hridya Valsaraju" <hridya@google.com>
  276. Description: Number of free segments in disk.
  277. What: /sys/fs/f2fs/<disk>/cp_foreground_calls
  278. Date: September 2019
  279. Contact: "Hridya Valsaraju" <hridya@google.com>
  280. Description: Number of checkpoint operations performed on demand. Available when
  281. CONFIG_F2FS_STAT_FS=y.
  282. What: /sys/fs/f2fs/<disk>/cp_background_calls
  283. Date: September 2019
  284. Contact: "Hridya Valsaraju" <hridya@google.com>
  285. Description: Number of checkpoint operations performed in the background to
  286. free segments. Available when CONFIG_F2FS_STAT_FS=y.
  287. What: /sys/fs/f2fs/<disk>/gc_foreground_calls
  288. Date: September 2019
  289. Contact: "Hridya Valsaraju" <hridya@google.com>
  290. Description: Number of garbage collection operations performed on demand.
  291. Available when CONFIG_F2FS_STAT_FS=y.
  292. What: /sys/fs/f2fs/<disk>/gc_background_calls
  293. Date: September 2019
  294. Contact: "Hridya Valsaraju" <hridya@google.com>
  295. Description: Number of garbage collection operations triggered in background.
  296. Available when CONFIG_F2FS_STAT_FS=y.
  297. What: /sys/fs/f2fs/<disk>/moved_blocks_foreground
  298. Date: September 2019
  299. Contact: "Hridya Valsaraju" <hridya@google.com>
  300. Description: Number of blocks moved by garbage collection in foreground.
  301. Available when CONFIG_F2FS_STAT_FS=y.
  302. What: /sys/fs/f2fs/<disk>/moved_blocks_background
  303. Date: September 2019
  304. Contact: "Hridya Valsaraju" <hridya@google.com>
  305. Description: Number of blocks moved by garbage collection in background.
  306. Available when CONFIG_F2FS_STAT_FS=y.
  307. What: /sys/fs/f2fs/<disk>/avg_vblocks
  308. Date: September 2019
  309. Contact: "Hridya Valsaraju" <hridya@google.com>
  310. Description: Average number of valid blocks.
  311. Available when CONFIG_F2FS_STAT_FS=y.
  312. What: /sys/fs/f2fs/<disk>/mounted_time_sec
  313. Date: February 2020
  314. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  315. Description: Show the mounted time in secs of this partition.
  316. What: /sys/fs/f2fs/<disk>/data_io_flag
  317. Date: April 2020
  318. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  319. Description: Give a way to attach REQ_META|FUA to data writes
  320. given temperature-based bits. Now the bits indicate:
  321. +-------------------+-------------------+
  322. | REQ_META | REQ_FUA |
  323. +------+------+-----+------+------+-----+
  324. | 5 | 4 | 3 | 2 | 1 | 0 |
  325. +------+------+-----+------+------+-----+
  326. | Cold | Warm | Hot | Cold | Warm | Hot |
  327. +------+------+-----+------+------+-----+
  328. What: /sys/fs/f2fs/<disk>/node_io_flag
  329. Date: June 2020
  330. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  331. Description: Give a way to attach REQ_META|FUA to node writes
  332. given temperature-based bits. Now the bits indicate:
  333. +-------------------+-------------------+
  334. | REQ_META | REQ_FUA |
  335. +------+------+-----+------+------+-----+
  336. | 5 | 4 | 3 | 2 | 1 | 0 |
  337. +------+------+-----+------+------+-----+
  338. | Cold | Warm | Hot | Cold | Warm | Hot |
  339. +------+------+-----+------+------+-----+
  340. What: /sys/fs/f2fs/<disk>/iostat_period_ms
  341. Date: April 2020
  342. Contact: "Daeho Jeong" <daehojeong@google.com>
  343. Description: Give a way to change iostat_period time. 3secs by default.
  344. The new iostat trace gives stats gap given the period.
  345. What: /sys/fs/f2fs/<disk>/max_io_bytes
  346. Date: December 2020
  347. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  348. Description: This gives a control to limit the bio size in f2fs.
  349. Default is zero, which will follow underlying block layer limit,
  350. whereas, if it has a certain bytes value, f2fs won't submit a
  351. bio larger than that size.
  352. What: /sys/fs/f2fs/<disk>/stat/sb_status
  353. Date: December 2020
  354. Contact: "Chao Yu" <yuchao0@huawei.com>
  355. Description: Show status of f2fs superblock in real time.
  356. ====== ===================== =================================
  357. value sb status macro description
  358. 0x1 SBI_IS_DIRTY dirty flag for checkpoint
  359. 0x2 SBI_IS_CLOSE specify unmounting
  360. 0x4 SBI_NEED_FSCK need fsck.f2fs to fix
  361. 0x8 SBI_POR_DOING recovery is doing or not
  362. 0x10 SBI_NEED_SB_WRITE need to recover superblock
  363. 0x20 SBI_NEED_CP need to checkpoint
  364. 0x40 SBI_IS_SHUTDOWN shutdown by ioctl
  365. 0x80 SBI_IS_RECOVERED recovered orphan/data
  366. 0x100 SBI_CP_DISABLED CP was disabled last mount
  367. 0x200 SBI_CP_DISABLED_QUICK CP was disabled quickly
  368. 0x400 SBI_QUOTA_NEED_FLUSH need to flush quota info in CP
  369. 0x800 SBI_QUOTA_SKIP_FLUSH skip flushing quota in current CP
  370. 0x1000 SBI_QUOTA_NEED_REPAIR quota file may be corrupted
  371. 0x2000 SBI_IS_RESIZEFS resizefs is in process
  372. ====== ===================== =================================
  373. What: /sys/fs/f2fs/<disk>/ckpt_thread_ioprio
  374. Date: January 2021
  375. Contact: "Daeho Jeong" <daehojeong@google.com>
  376. Description: Give a way to change checkpoint merge daemon's io priority.
  377. Its default value is "be,3", which means "BE" I/O class and
  378. I/O priority "3". We can select the class between "rt" and "be",
  379. and set the I/O priority within valid range of it. "," delimiter
  380. is necessary in between I/O class and priority number.
  381. What: /sys/fs/f2fs/<disk>/ovp_segments
  382. Date: March 2021
  383. Contact: "Jaegeuk Kim" <jaegeuk@kernel.org>
  384. Description: Shows the number of overprovision segments.
  385. What: /sys/fs/f2fs/<disk>/compr_written_block
  386. Date: March 2021
  387. Contact: "Daeho Jeong" <daehojeong@google.com>
  388. Description: Show the block count written after compression since mount. Note
  389. that when the compressed blocks are deleted, this count doesn't
  390. decrease. If you write "0" here, you can initialize
  391. compr_written_block and compr_saved_block to "0".
  392. What: /sys/fs/f2fs/<disk>/compr_saved_block
  393. Date: March 2021
  394. Contact: "Daeho Jeong" <daehojeong@google.com>
  395. Description: Show the saved block count with compression since mount. Note
  396. that when the compressed blocks are deleted, this count doesn't
  397. decrease. If you write "0" here, you can initialize
  398. compr_written_block and compr_saved_block to "0".
  399. What: /sys/fs/f2fs/<disk>/compr_new_inode
  400. Date: March 2021
  401. Contact: "Daeho Jeong" <daehojeong@google.com>
  402. Description: Show the count of inode newly enabled for compression since mount.
  403. Note that when the compression is disabled for the files, this count
  404. doesn't decrease. If you write "0" here, you can initialize
  405. compr_new_inode to "0".
  406. What: /sys/fs/f2fs/<disk>/atgc_candidate_ratio
  407. Date: May 2021
  408. Contact: "Chao Yu" <yuchao0@huawei.com>
  409. Description: When ATGC is on, it controls candidate ratio in order to limit total
  410. number of potential victim in all candidates, the value should be in
  411. range of [0, 100], by default it was initialized as 20(%).
  412. What: /sys/fs/f2fs/<disk>/atgc_candidate_count
  413. Date: May 2021
  414. Contact: "Chao Yu" <yuchao0@huawei.com>
  415. Description: When ATGC is on, it controls candidate count in order to limit total
  416. number of potential victim in all candidates, by default it was
  417. initialized as 10 (sections).
  418. What: /sys/fs/f2fs/<disk>/atgc_age_weight
  419. Date: May 2021
  420. Contact: "Chao Yu" <yuchao0@huawei.com>
  421. Description: When ATGC is on, it controls age weight to balance weight proportion
  422. in between aging and valid blocks, the value should be in range of
  423. [0, 100], by default it was initialized as 60(%).
  424. What: /sys/fs/f2fs/<disk>/atgc_age_threshold
  425. Date: May 2021
  426. Contact: "Chao Yu" <yuchao0@huawei.com>
  427. Description: When ATGC is on, it controls age threshold to bypass GCing young
  428. candidates whose age is not beyond the threshold, by default it was
  429. initialized as 604800 seconds (equals to 7 days).
  430. What: /sys/fs/f2fs/<disk>/gc_reclaimed_segments
  431. Date: July 2021
  432. Contact: "Daeho Jeong" <daehojeong@google.com>
  433. Description: Show how many segments have been reclaimed by GC during a specific
  434. GC mode (0: GC normal, 1: GC idle CB, 2: GC idle greedy,
  435. 3: GC idle AT, 4: GC urgent high, 5: GC urgent low)
  436. You can re-initialize this value to "0".
  437. What: /sys/fs/f2fs/<disk>/gc_segment_mode
  438. Date: July 2021
  439. Contact: "Daeho Jeong" <daehojeong@google.com>
  440. Description: You can control for which gc mode the "gc_reclaimed_segments" node shows.
  441. Refer to the description of the modes in "gc_reclaimed_segments".