As Fan Li reported, there is no user traversing nid_list[ALLOC_NID_LIST]
which is used for tracking preallocated nids. Let's drop it, and only
track preallocated nids in free_nid_root radix-tree.
Reported-by: Fan Li <fanofcode.li@samsung.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch makes sure it returns a positive value instead of a probable
casted negative value as shrink count.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
During free nid allocation, in order to do preallocation, we will tag free
nid entry as allocated one and still leave it in free nid list, for other
allocators who want to grab free nids, it needs to traverse the free nid
list for lookup. It becomes overhead in scenario of allocating free nid
intensively by multithreads.
This patch splits free nid list to two list: {free,alloc}_nid_list, to
keep free nids and preallocated free nids separately, after that, traverse
latency will be gone, besides split nid_cnt for separate statistic.
Additionally, introduce __insert_nid_to_list and __remove_nid_from_list for
cleanup.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: modify f2fs_bug_on to avoid needless branches]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
The readahead nat pages are more likely to be reclaimed quickly, so it'd better
to gather more free nids in advance.
And, let's keep some free nids as much as possible.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If there is no candidates for shrinking slab entries, we don't need to traverse
any trees at all.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
[Jaegeuk Kim: fix missing initialization reported by Yunlei He]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
It would be better to use atomic variable for total_extent_tree.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch introduces __count_free_nids/try_to_free_nids and registers
them in slab shrinker for shrinking under memory pressure.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We don't need to handle the duplicate extent information.
The integrated rule is:
- update on-disk extent with largest one tracked by in-memory extent_cache
- destroy extent_tree for the truncation case
- drop per-inode extent_cache by shrinker
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch introduces a shrinker targeting to reduce memory footprint consumed
by a number of in-memory f2fs data structures.
In addition, it newly adds:
- sbi->umount_mutex to avoid data races on shrinker and put_super
- sbi->shruinker_run_no to not revisit objects
Note that the basic implementation was copied from fs/ubifs/shrinker.c
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
