f2fs: produce more nids and reduce readahead nats
The readahead nat pages are more likely to be reclaimed quickly, so it'd better
to gather more free nids in advance.
And, let's keep some free nids as much as possible.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 4f16f48..0553b51 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -942,6 +942,8 @@
static void unblock_operations(struct f2fs_sb_info *sbi)
{
up_write(&sbi->node_write);
+
+ build_free_nids(sbi);
f2fs_unlock_all(sbi);
}
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index cf4cf1a..f4aa761 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2008,6 +2008,7 @@
int fsync_node_pages(struct f2fs_sb_info *, struct inode *,
struct writeback_control *, bool);
int sync_node_pages(struct f2fs_sb_info *, struct writeback_control *);
+void build_free_nids(struct f2fs_sb_info *);
bool alloc_nid(struct f2fs_sb_info *, nid_t *);
void alloc_nid_done(struct f2fs_sb_info *, nid_t);
void alloc_nid_failed(struct f2fs_sb_info *, nid_t);
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index da445f4..4ba312a 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -1782,7 +1782,7 @@
}
}
-static void build_free_nids(struct f2fs_sb_info *sbi)
+void build_free_nids(struct f2fs_sb_info *sbi)
{
struct f2fs_nm_info *nm_i = NM_I(sbi);
struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
@@ -1791,7 +1791,7 @@
nid_t nid = nm_i->next_scan_nid;
/* Enough entries */
- if (nm_i->fcnt > NAT_ENTRY_PER_BLOCK)
+ if (nm_i->fcnt >= NAT_ENTRY_PER_BLOCK)
return;
/* readahead nat pages to be scanned */
@@ -1929,12 +1929,15 @@
struct free_nid *i, *next;
int nr = nr_shrink;
+ if (nm_i->fcnt <= MAX_FREE_NIDS)
+ return 0;
+
if (!mutex_trylock(&nm_i->build_lock))
return 0;
spin_lock(&nm_i->free_nid_list_lock);
list_for_each_entry_safe(i, next, &nm_i->free_nid_list, list) {
- if (nr_shrink <= 0 || nm_i->fcnt <= NAT_ENTRY_PER_BLOCK)
+ if (nr_shrink <= 0 || nm_i->fcnt <= MAX_FREE_NIDS)
break;
if (i->state == NID_ALLOC)
continue;
diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
index 673ce92..fc76845 100644
--- a/fs/f2fs/node.h
+++ b/fs/f2fs/node.h
@@ -15,9 +15,10 @@
#define NAT_BLOCK_OFFSET(start_nid) (start_nid / NAT_ENTRY_PER_BLOCK)
/* # of pages to perform synchronous readahead before building free nids */
-#define FREE_NID_PAGES 4
+#define FREE_NID_PAGES 8
+#define MAX_FREE_NIDS (NAT_ENTRY_PER_BLOCK * FREE_NID_PAGES)
-#define DEF_RA_NID_PAGES 4 /* # of nid pages to be readaheaded */
+#define DEF_RA_NID_PAGES 0 /* # of nid pages to be readaheaded */
/* maximum readahead size for node during getting data blocks */
#define MAX_RA_NODE 128
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index a5bd8f8..c50f02d 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -430,7 +430,9 @@
try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK);
if (!available_free_memory(sbi, FREE_NIDS))
- try_to_free_nids(sbi, NAT_ENTRY_PER_BLOCK * FREE_NID_PAGES);
+ try_to_free_nids(sbi, MAX_FREE_NIDS);
+ else
+ build_free_nids(sbi);
/* checkpoint is the only way to shrink partial cached entries */
if (!available_free_memory(sbi, NAT_ENTRIES) ||
diff --git a/fs/f2fs/shrinker.c b/fs/f2fs/shrinker.c
index c997717..30fb481 100644
--- a/fs/f2fs/shrinker.c
+++ b/fs/f2fs/shrinker.c
@@ -13,6 +13,7 @@
#include <linux/f2fs_fs.h>
#include "f2fs.h"
+#include "node.h"
static LIST_HEAD(f2fs_list);
static DEFINE_SPINLOCK(f2fs_list_lock);
@@ -25,8 +26,8 @@
static unsigned long __count_free_nids(struct f2fs_sb_info *sbi)
{
- if (NM_I(sbi)->fcnt > NAT_ENTRY_PER_BLOCK)
- return NM_I(sbi)->fcnt - NAT_ENTRY_PER_BLOCK;
+ if (NM_I(sbi)->fcnt > MAX_FREE_NIDS)
+ return NM_I(sbi)->fcnt - MAX_FREE_NIDS;
return 0;
}