From 4b10651864429386ae931167d3518f37a8c762e0 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Fri, 6 Aug 2021 08:05:58 +0800 Subject: [PATCH] f2fs: avoid unneeded memory allocation in __add_ino_entry() __add_ino_entry() will allocate slab cache even if we have already cached ino entry in radix tree, e.g. for case of multiple devices. Let's check radix tree first under protection of rcu lock to see whether we need to do slab allocation, it will mitigate memory pressure from "f2fs_ino_entry" slab cache. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/checkpoint.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c index 7f6745f4630e..5b6ddeae1107 100644 --- a/fs/f2fs/checkpoint.c +++ b/fs/f2fs/checkpoint.c @@ -465,16 +465,28 @@ static void __add_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, unsigned int devidx, int type) { struct inode_management *im = &sbi->im[type]; - struct ino_entry *e, *tmp; + struct ino_entry *e = NULL, *new = NULL; + + if (type == FLUSH_INO) { + rcu_read_lock(); + e = radix_tree_lookup(&im->ino_root, ino); + rcu_read_unlock(); + } - tmp = f2fs_kmem_cache_alloc(ino_entry_slab, GFP_NOFS); +retry: + if (!e) + new = f2fs_kmem_cache_alloc(ino_entry_slab, GFP_NOFS); radix_tree_preload(GFP_NOFS | __GFP_NOFAIL); spin_lock(&im->ino_lock); e = radix_tree_lookup(&im->ino_root, ino); if (!e) { - e = tmp; + if (!new) { + spin_unlock(&im->ino_lock); + goto retry; + } + e = new; if (unlikely(radix_tree_insert(&im->ino_root, ino, e))) f2fs_bug_on(sbi, 1); @@ -492,8 +504,8 @@ static void __add_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, spin_unlock(&im->ino_lock); radix_tree_preload_end(); - if (e != tmp) - kmem_cache_free(ino_entry_slab, tmp); + if (new && e != new) + kmem_cache_free(ino_entry_slab, new); } static void __remove_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, int type) -- 2.34.1