From 042be373adf719ab64c4a44ae809d110826becbf Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Fri, 8 May 2020 17:50:20 +0800 Subject: [PATCH] f2fs: shrink spinlock coverage In f2fs_try_to_free_nids(), .nid_list_lock spinlock critical region will increase as expected shrink number increase, to avoid spining other CPUs for long time, we change to release nid caches with small batch each time under .nid_list_lock coverage. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/node.c | 25 +++++++++++++++---------- fs/f2fs/node.h | 3 +++ 2 files changed, 18 insertions(+), 10 deletions(-) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 4da0d8713df5..1db8cabf727e 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -2488,7 +2488,6 @@ void f2fs_alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid) int f2fs_try_to_free_nids(struct f2fs_sb_info *sbi, int nr_shrink) { struct f2fs_nm_info *nm_i = NM_I(sbi); - struct free_nid *i, *next; int nr = nr_shrink; if (nm_i->nid_cnt[FREE_NID] <= MAX_FREE_NIDS) @@ -2497,17 +2496,23 @@ int f2fs_try_to_free_nids(struct f2fs_sb_info *sbi, int nr_shrink) if (!mutex_trylock(&nm_i->build_lock)) return 0; - spin_lock(&nm_i->nid_list_lock); - list_for_each_entry_safe(i, next, &nm_i->free_nid_list, list) { - if (nr_shrink <= 0 || - nm_i->nid_cnt[FREE_NID] <= MAX_FREE_NIDS) - break; + while (nr_shrink && nm_i->nid_cnt[FREE_NID] > MAX_FREE_NIDS) { + struct free_nid *i, *next; + unsigned int batch = SHRINK_NID_BATCH_SIZE; - __remove_free_nid(sbi, i, FREE_NID); - kmem_cache_free(free_nid_slab, i); - nr_shrink--; + spin_lock(&nm_i->nid_list_lock); + list_for_each_entry_safe(i, next, &nm_i->free_nid_list, list) { + if (!nr_shrink || !batch || + nm_i->nid_cnt[FREE_NID] <= MAX_FREE_NIDS) + break; + __remove_free_nid(sbi, i, FREE_NID); + kmem_cache_free(free_nid_slab, i); + nr_shrink--; + batch--; + } + spin_unlock(&nm_i->nid_list_lock); } - spin_unlock(&nm_i->nid_list_lock); + mutex_unlock(&nm_i->build_lock); return nr - nr_shrink; diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h index 6a2011deea23..69e5859e993c 100644 --- a/fs/f2fs/node.h +++ b/fs/f2fs/node.h @@ -15,6 +15,9 @@ #define FREE_NID_PAGES 8 #define MAX_FREE_NIDS (NAT_ENTRY_PER_BLOCK * FREE_NID_PAGES) +/* size of free nid batch when shrinking */ +#define SHRINK_NID_BATCH_SIZE 8 + #define DEF_RA_NID_PAGES 0 /* # of nid pages to be readaheaded */ /* maximum readahead size for node during getting data blocks */