Messages in this thread Patch in this message | | | From | Chao Yu <> | Subject | [PATCH] f2fs: reduce lock overhead of extent node releasing | Date | Thu, 2 Jul 2015 20:40:12 +0800 |
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From e5c6600d01c4462c4e1ee0c70ec1d9319862077d Mon Sep 17 00:00:00 2001 From: Chao Yu <chao2.yu@samsung.com> Date: Thu, 2 Jul 2015 18:52:46 +0800 Subject: [PATCH] f2fs: reduce lock overhead of extent node releasing
Open and close critical section for each extent node when traversing rb-tree results in high overhead of cpu, slows thing down.
This patch alternates to batch mode for removing extent nodes under spin lock.
Signed-off-by: Chao Yu <chao2.yu@samsung.com> --- fs/f2fs/data.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 6a706dd..7fb56a0 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -441,19 +441,31 @@ static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi, struct extent_node *en; unsigned int count = et->count; - node = rb_first(&et->root); - while (node) { - next = rb_next(node); - en = rb_entry(node, struct extent_node, rb_node); + if (!et->count) + return 0; + + /* 1. remove all extent nodes in global lru list */ + if (free_all) { + spin_lock(&sbi->extent_lock); + node = rb_first(&et->root); + while (node) { + next = rb_next(node); + en = rb_entry(node, struct extent_node, rb_node); - if (free_all) { - spin_lock(&sbi->extent_lock); if (!list_empty(&en->list)) list_del_init(&en->list); - spin_unlock(&sbi->extent_lock); + node = next; } + spin_unlock(&sbi->extent_lock); + } + + /* 2. release all extent nodes which are not in global lru list */ + node = rb_first(&et->root); + while (node) { + next = rb_next(node); + en = rb_entry(node, struct extent_node, rb_node); - if (free_all || list_empty(&en->list)) { + if (list_empty(&en->list)) { __detach_extent_node(sbi, et, en); kmem_cache_free(extent_node_slab, en); } -- 2.4.2
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