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path: root/fs/f2fs/gc.h
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2016-01-11f2fs: detect idle time depending on user behaviorJaegeuk Kim
This patch adds last time that user requested filesystem operations. This information is used to detect whether system is idle or not later. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-10-09f2fs: support synchronous gc in ioctlChao Yu
This patch drops in batches gc triggered through ioctl, since user can easily control the gc by designing the loop around the ->ioctl. We support synchronous gc by forcing using FG_GC in f2fs_gc, so with it, user can make sure that in this round all blocks gced were persistent in the device until ioctl returned. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-08-04f2fs: add new ioctl F2FS_IOC_GARBAGE_COLLECTChao Yu
When background gc is off, the only way to trigger gc is executing a force gc in some operations who wants to grab space in disk. The executing condition is limited: to execute force gc, we should wait for the time when there is almost no more free section for LFS allocation. This seems not reasonable for our user who wants to control triggering gc by himself. This patch introduces F2FS_IOC_GARBAGE_COLLECT interface for triggering garbage collection by using ioctl. It provides our users one more option to trigger gc. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-02-12f2fs: fix sparse warningsJaegeuk Kim
This patch resolves the following warnings. include/trace/events/f2fs.h:150:1: warning: expression using sizeof bool include/trace/events/f2fs.h:180:1: warning: expression using sizeof bool include/trace/events/f2fs.h:990:1: warning: expression using sizeof bool include/trace/events/f2fs.h:990:1: warning: expression using sizeof bool include/trace/events/f2fs.h:150:1: warning: odd constant _Bool cast (ffffffffffffffff becomes 1) include/trace/events/f2fs.h:180:1: warning: odd constant _Bool cast (ffffffffffffffff becomes 1) include/trace/events/f2fs.h:990:1: warning: odd constant _Bool cast (ffffffffffffffff becomes 1) include/trace/events/f2fs.h:990:1: warning: odd constant _Bool cast (ffffffffffffffff becomes 1) fs/f2fs/checkpoint.c:27:19: warning: symbol 'inode_entry_slab' was not declared. Should it be static? fs/f2fs/checkpoint.c:577:15: warning: cast to restricted __le32 fs/f2fs/checkpoint.c:592:15: warning: cast to restricted __le32 fs/f2fs/trace.c:19:1: warning: symbol 'pids' was not declared. Should it be static? fs/f2fs/trace.c:21:21: warning: symbol 'last_io' was not declared. Should it be static? Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-02-12f2fs: clean up {in,de}create_sleep_timeChao Yu
Use pointer parameter @wait to pass result in {in,de}create_sleep_time for cleanup. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-01-10f2fs: reuse inode_entry_slab in gc procedure for using slab more effectivelyChao Yu
There are two slab cache inode_entry_slab and winode_slab using the same structure as below: struct dir_inode_entry { struct list_head list; /* list head */ struct inode *inode; /* vfs inode pointer */ }; struct inode_entry { struct list_head list; struct inode *inode; }; It's a little waste that the two cache can not share their memory space for each other. So in this patch we remove one redundant winode_slab slab cache, then use more universal name struct inode_entry as remaining data structure name of slab, finally we reuse the inode_entry_slab to store dirty dir item and gc item for more effective. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-12-02f2fs: more fast lookup for gc_inode listChangman Lee
If there are many inodes that have data blocks in victim segment, it takes long time to find a inode in gc_inode list. Let's use radix_tree to reduce lookup time. Signed-off-by: Changman Lee <cm224.lee@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-08-19f2fs: fix typoarter97
Fix typo and some grammatical errors. The words "filesystem" and "readahead" are being used without the space treewide. Signed-off-by: Park Ju Hyung <qkrwngud825@gmail.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-01-08f2fs: add a sysfs entry to control max_victim_searchJaegeuk Kim
Previously during SSR and GC, the maximum number of retrials to find a victim segment was hard-coded by MAX_VICTIM_SEARCH, 4096 by default. This number makes an effect on IO locality, when SSR mode is activated, which results in performance fluctuation on some low-end devices. If max_victim_search = 4, the victim will be searched like below. ("D" represents a dirty segment, and "*" indicates a selected victim segment.) D1 D2 D3 D4 D5 D6 D7 D8 D9 [ * ] [ * ] [ * ] [ ....] This patch adds a sysfs entry to control the number dynamically through: /sys/fs/f2fs/$dev/max_victim_search Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-09-05f2fs: optimize gc for better performanceJin Xu
This patch improves the gc efficiency by optimizing the victim selection policy. With this optimization, the random re-write performance could increase up to 20%. For f2fs, when disk is in shortage of free spaces, gc will selects dirty segments and moves valid blocks around for making more space available. The gc cost of a segment is determined by the valid blocks in the segment. The less the valid blocks, the higher the efficiency. The ideal victim segment is the one that has the most garbage blocks. Currently, it searches up to 20 dirty segments for a victim segment. The selected victim is not likely the best victim for gc when there are much more dirty segments. Why not searching more dirty segments for a better victim? The cost of searching dirty segments is negligible in comparison to moving blocks. In this patch, it enlarges the MAX_VICTIM_SEARCH to 4096 to make the search more aggressively for a possible better victim. Since it also applies to victim selection for SSR, it will likely improve the SSR efficiency as well. The test case is simple. It creates as many files until the disk full. The size for each file is 32KB. Then it writes as many as 100000 records of 4KB size to random offsets of random files in sync mode. The testing was done on a 2GB partition of a SDHC card. Let's see the test result of f2fs without and with the patch. --------------------------------------- 2GB partition, SDHC create 52023 files of size 32768 bytes random re-write 100000 records of 4KB --------------------------------------- | file creation (s) | rewrite time (s) | gc count | gc garbage blocks | [no patch] 341 4227 1174 174840 [patched] 324 2958 645 106682 It's obvious that, with the patch, f2fs finishes the test in 20+% less time than without the patch. And internally it does much less gc with higher efficiency than before. Since the performance improvement is related to gc, it might not be so obvious for other tests that do not trigger gc as often as this one ( This is because f2fs selects dirty segments for SSR use most of the time when free space is in shortage). The well-known iozone test tool was not used for benchmarking the patch becuase it seems do not have a test case that performs random re-write on a full disk. This patch is the revised version based on the suggestion from Jaegeuk Kim. Signed-off-by: Jin Xu <jinuxstyle@gmail.com> [Jaegeuk Kim: suggested simpler solution] Reviewed-by: Jaegeuk Kim <jaegeuk.kim@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-08-06f2fs: add sysfs entries to select the gc policyNamjae Jeon
Add sysfs entry gc_idle to control the gc policy. Where gc_idle = 1 corresponds to selecting a cost benefit approach, while gc_idle = 2 corresponds to selecting a greedy approach to garbage collection. The selection is mutually exclusive one approach will work at any point. If gc_idle = 0, then this option is disabled. Cc: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com> Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com> [Jaegeuk Kim: change the select_gc_type() flow slightly] Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-08-06f2fs: add sysfs support for controlling the gc_threadNamjae Jeon
Add sysfs entries to control the timing parameters for f2fs gc thread. Various Sysfs options introduced are: gc_min_sleep_time: Min Sleep time for GC in ms gc_max_sleep_time: Max Sleep time for GC in ms gc_no_gc_sleep_time: Default Sleep time for GC in ms Cc: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com> Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com> [Jaegeuk Kim: fix an umount bug and some minor changes] Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-04-26f2fs: avoid frequent background GCJaegeuk Kim
If there is no victim segments selected by background GC, let's wait a little bit longer time to collect dirty segments. By default, let's give 5 minutes. Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-11f2fs: clarify and enhance the f2fs_gc flowJaegeuk Kim
This patch makes clearer the ambiguous f2fs_gc flow as follows. 1. Remove intermediate checkpoint condition during f2fs_gc (i.e., should_do_checkpoint() and GC_BLOCKED) 2. Remove unnecessary return values of f2fs_gc because of #1. (i.e., GC_NODE, GC_OK, etc) 3. Simplify write_checkpoint() because of #2. 4. Clarify the main f2fs_gc flow. o monitor how many freed sections during one iteration of do_garbage_collect(). o do GC more without checkpoints if we can't get enough free sections. o do checkpoint once we've got enough free sections through forground GCs. 5. Adopt thread-logging (Slack-Space-Recycle) scheme more aggressively on data log types. See. get_ssr_segement() Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-11f2fs: make an accessor to get sections for particular block typeNamjae Jeon
Introduce accessor to get the sections based upon the block type (node,dents...) and modify the functions : should_do_checkpoint, has_not_enough_free_secs to use this accessor function to get the node sections and dent sections. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-11f2fs: name gc task as per the block deviceNamjae Jeon
Currently GC task is started for each f2fs formatted/mounted device. But, when we check the task list, using 'ps', there is no distinguishing factor between the tasks. So, name the task as per the block device just like the flusher threads. Also, remove the macro GC_THREAD_NAME and instead use the name: f2fs_gc to avoid name length truncation, as the command length is 16 -> TASK_COMM_LEN 16 and example name like: f2fs_gc_task:8:16 -> this exceeds name length Before Patch for 2 F2FS formatted partitions: root 28061 0.0 0.0 0 0 ? S 10:31 0:00 [f2fs_gc_task] root 28087 0.0 0.0 0 0 ? S 10:32 0:00 [f2fs_gc_task] After Patch: root 16756 0.0 0.0 0 0 ? S 14:57 0:00 [f2fs_gc-8:18] root 16765 0.0 0.0 0 0 ? S 14:57 0:00 [f2fs_gc-8:19] Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-11f2fs: adjust kernel coding styleJaegeuk Kim
As pointed out by Randy Dunlap, this patch removes all usage of "/**" for comment blocks. Instead, just use "/*". Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-11f2fs: add garbage collection functionsJaegeuk Kim
This adds on-demand and background cleaning functions. - The basic background cleaning policy is trying to do cleaning jobs as much as possible whenever the system is idle. Once the background cleaning is done, the cleaner sleeps an amount of time not to interfere with VFS calls. The time is dynamically adjusted according to the status of whole segments, which is decreased when the following conditions are satisfied. . GC is not conducted currently, and . IO subsystem is idle by checking the number of requets in bdev's request list, and . There are enough dirty segments. Otherwise, the time is increased incrementally until to the maximum time. Note that, min and max times are 10 secs and 30 secs by default. - F2FS adopts a default victim selection policy where background cleaning uses a cost-benefit algorithm, while on-demand cleaning uses a greedy algorithm. - The method of moving data during the cleaning is slightly different between background and on-demand cleaning schemes. In the case of background cleaning, F2FS loads the data, and marks them as dirty. Then, F2FS expects that the data will be moved by flusher or VM. In the case of on-demand cleaning, F2FS should move the data right away. - In order to identify valid blocks in a victim segment, F2FS scans the bitmap of the segment managed as an SIT entry. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>