[09/12] f2fs: shrink nat_cache entries
diff mbox

Message ID 1435603176-63219-9-git-send-email-jaegeuk@kernel.org
State New
Headers show

Commit Message

Jaegeuk Kim June 29, 2015, 6:39 p.m. UTC
This patch registers shrinking nat_cache entries.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 fs/f2fs/node.c     |  6 +++---
 fs/f2fs/segment.c  |  8 ++++++--
 fs/f2fs/shrinker.c | 11 +++++++++--
 3 files changed, 18 insertions(+), 7 deletions(-)

Comments

Chao Yu July 2, 2015, 12:33 p.m. UTC | #1
> -----Original Message-----
> From: Jaegeuk Kim [mailto:jaegeuk@kernel.org]
> Sent: Tuesday, June 30, 2015 2:40 AM
> To: linux-kernel@vger.kernel.org; linux-fsdevel@vger.kernel.org;
> linux-f2fs-devel@lists.sourceforge.net
> Cc: Jaegeuk Kim
> Subject: [f2fs-dev] [PATCH 09/12] f2fs: shrink nat_cache entries
> 
> This patch registers shrinking nat_cache entries.
> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
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Patch
diff mbox

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index d9c5242..318ee86 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -328,11 +328,11 @@  static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
 int try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink)
 {
 	struct f2fs_nm_info *nm_i = NM_I(sbi);
+	int nr = nr_shrink;
 
-	if (available_free_memory(sbi, NAT_ENTRIES))
+	if (!down_write_trylock(&nm_i->nat_tree_lock))
 		return 0;
 
-	down_write(&nm_i->nat_tree_lock);
 	while (nr_shrink && !list_empty(&nm_i->nat_entries)) {
 		struct nat_entry *ne;
 		ne = list_first_entry(&nm_i->nat_entries,
@@ -341,7 +341,7 @@  int try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink)
 		nr_shrink--;
 	}
 	up_write(&nm_i->nat_tree_lock);
-	return nr_shrink;
+	return nr - nr_shrink;
 }
 
 /*
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 1eb3437..dec3afb 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -305,8 +305,12 @@  void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
 	/* try to shrink extent cache when there is no enough memory */
 	f2fs_shrink_extent_tree(sbi, EXTENT_CACHE_SHRINK_NUMBER);
 
-	/* check the # of cached NAT entries and prefree segments */
-	if (try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK) ||
+	/* check the # of cached NAT entries */
+	if (!available_free_memory(sbi, NAT_ENTRIES))
+		try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK);
+
+	/* checkpoint is the only way to shrink partial cached entries */
+	if (!available_free_memory(sbi, NAT_ENTRIES) ||
 			excess_prefree_segs(sbi) ||
 			!available_free_memory(sbi, INO_ENTRIES))
 		f2fs_sync_fs(sbi->sb, true);
diff --git a/fs/f2fs/shrinker.c b/fs/f2fs/shrinker.c
index a680145..3350ac3 100644
--- a/fs/f2fs/shrinker.c
+++ b/fs/f2fs/shrinker.c
@@ -18,6 +18,11 @@  static LIST_HEAD(f2fs_list);
 static DEFINE_SPINLOCK(f2fs_list_lock);
 static unsigned int shrinker_run_no;
 
+static unsigned long __count_nat_entries(struct f2fs_sb_info *sbi)
+{
+	return NM_I(sbi)->nat_cnt - NM_I(sbi)->dirty_nat_cnt;
+}
+
 unsigned long f2fs_shrink_count(struct shrinker *shrink,
 				struct shrink_control *sc)
 {
@@ -37,7 +42,8 @@  unsigned long f2fs_shrink_count(struct shrinker *shrink,
 		}
 		spin_unlock(&f2fs_list_lock);
 
-		/* TODO: count # of objects */
+		/* shrink clean nat cache entries */
+		count += __count_nat_entries(sbi);
 
 		spin_lock(&f2fs_list_lock);
 		p = p->next;
@@ -76,7 +82,8 @@  unsigned long f2fs_shrink_scan(struct shrinker *shrink,
 
 		sbi->shrinker_run_no = run_no;
 
-		/* TODO: shrink caches */
+		/* shrink clean nat cache entries */
+		freed += try_to_free_nats(sbi, nr);
 
 		spin_lock(&f2fs_list_lock);
 		p = p->next;