lkml.org 
[lkml]   [2015]   [Jun]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/2] f2fs: shrink unreferenced extent_caches first
Date
If an extent_tree entry has a zero reference count, we can drop it from the
cache in higher priority rather than currently referencing entries.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
fs/f2fs/data.c | 51 +++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 41 insertions(+), 10 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 8f059e0..a0a0e2b 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -661,21 +661,54 @@ unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
struct radix_tree_root *root = &sbi->extent_tree_root;
unsigned int found;
unsigned int node_cnt = 0, tree_cnt = 0;
+ int remained;

if (!test_opt(sbi, EXTENT_CACHE))
return 0;

+ if (!down_write_trylock(&sbi->extent_tree_lock))
+ goto out;
+
+ /* 1. remove unreferenced extent tree */
+ while ((found = radix_tree_gang_lookup(root,
+ (void **)treevec, ino, EXT_TREE_VEC_SIZE))) {
+ unsigned i;
+
+ ino = treevec[found - 1]->ino + 1;
+ for (i = 0; i < found; i++) {
+ struct extent_tree *et = treevec[i];
+
+ if (!atomic_read(&et->refcount)) {
+ write_lock(&et->lock);
+ node_cnt += __free_extent_tree(sbi, et, true);
+ write_unlock(&et->lock);
+
+ radix_tree_delete(root, et->ino);
+ kmem_cache_free(extent_tree_slab, et);
+ sbi->total_ext_tree--;
+ tree_cnt++;
+
+ if (node_cnt + tree_cnt >= nr_shrink)
+ goto unlock_out;
+ }
+ }
+ }
+ up_write(&sbi->extent_tree_lock);
+
+ /* 2. remove LRU extent entries */
+ if (!down_write_trylock(&sbi->extent_tree_lock))
+ goto out;
+
+ remained = nr_shrink - (node_cnt + tree_cnt);
+
spin_lock(&sbi->extent_lock);
list_for_each_entry_safe(en, tmp, &sbi->extent_list, list) {
- if (!nr_shrink--)
+ if (!remained--)
break;
list_del_init(&en->list);
}
spin_unlock(&sbi->extent_lock);

- if (!down_write_trylock(&sbi->extent_tree_lock))
- goto out;
-
while ((found = radix_tree_gang_lookup(root,
(void **)treevec, ino, EXT_TREE_VEC_SIZE))) {
unsigned i;
@@ -687,14 +720,12 @@ unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
write_lock(&et->lock);
node_cnt += __free_extent_tree(sbi, et, false);
write_unlock(&et->lock);
- if (!atomic_read(&et->refcount) && !et->count) {
- radix_tree_delete(root, et->ino);
- kmem_cache_free(extent_tree_slab, et);
- sbi->total_ext_tree--;
- tree_cnt++;
- }
+
+ if (node_cnt + tree_cnt >= nr_shrink)
+ break;
}
}
+unlock_out:
up_write(&sbi->extent_tree_lock);
out:
trace_f2fs_shrink_extent_tree(sbi, node_cnt, tree_cnt);
--
2.1.1


\
 
 \ /
  Last update: 2015-07-01 04:01    [W:0.080 / U:0.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site