[PATCH 2/5] f2fs: use percpu_counter for page counters

From: Jaegeuk Kim
Date: Mon May 16 2016 - 18:31:45 EST


This patch substitutes percpu_counter for atomic_counter when counting
various types of pages.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/debug.c | 1 +
fs/f2fs/f2fs.h | 12 +++++++-----
fs/f2fs/super.c | 31 +++++++++++++++++++++++++++----
3 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index 37615b2..2210c7c 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -144,6 +144,7 @@ static void update_mem_info(struct f2fs_sb_info *sbi)
si->base_mem = sizeof(struct f2fs_sb_info) + sbi->sb->s_blocksize;
si->base_mem += 2 * sizeof(struct f2fs_inode_info);
si->base_mem += sizeof(*sbi->ckpt);
+ si->base_mem += sizeof(struct percpu_counter) * NR_COUNT_TYPE;

/* build sm */
si->base_mem += sizeof(struct f2fs_sm_info);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 24f8170..2851078 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -833,7 +833,9 @@ struct f2fs_sb_info {
block_t discard_blks; /* discard command candidats */
block_t last_valid_block_count; /* for recovery */
u32 s_next_generation; /* for NFS support */
- atomic_t nr_pages[NR_COUNT_TYPE]; /* # of pages, see count_type */
+
+ /* # of pages, see count_type */
+ struct percpu_counter nr_pages[NR_COUNT_TYPE];

struct f2fs_mount_info mount_opt; /* mount options */

@@ -1178,7 +1180,7 @@ static inline void dec_valid_block_count(struct f2fs_sb_info *sbi,

static inline void inc_page_count(struct f2fs_sb_info *sbi, int count_type)
{
- atomic_inc(&sbi->nr_pages[count_type]);
+ percpu_counter_inc(&sbi->nr_pages[count_type]);
set_sbi_flag(sbi, SBI_IS_DIRTY);
}

@@ -1191,7 +1193,7 @@ static inline void inode_inc_dirty_pages(struct inode *inode)

static inline void dec_page_count(struct f2fs_sb_info *sbi, int count_type)
{
- atomic_dec(&sbi->nr_pages[count_type]);
+ percpu_counter_dec(&sbi->nr_pages[count_type]);
}

static inline void inode_dec_dirty_pages(struct inode *inode)
@@ -1205,9 +1207,9 @@ static inline void inode_dec_dirty_pages(struct inode *inode)
F2FS_DIRTY_DENTS : F2FS_DIRTY_DATA);
}

-static inline int get_pages(struct f2fs_sb_info *sbi, int count_type)
+static inline s64 get_pages(struct f2fs_sb_info *sbi, int count_type)
{
- return atomic_read(&sbi->nr_pages[count_type]);
+ return percpu_counter_sum_positive(&sbi->nr_pages[count_type]);
}

static inline int get_dirty_pages(struct inode *inode)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 9df6d72..b3030ed 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -606,6 +606,14 @@ static void f2fs_destroy_inode(struct inode *inode)
call_rcu(&inode->i_rcu, f2fs_i_callback);
}

+static void destroy_percpu_info(struct f2fs_sb_info *sbi)
+{
+ int i;
+
+ for (i = 0; i < NR_COUNT_TYPE; i++)
+ percpu_counter_destroy(&sbi->nr_pages[i]);
+}
+
static void f2fs_put_super(struct super_block *sb)
{
struct f2fs_sb_info *sbi = F2FS_SB(sb);
@@ -667,6 +675,8 @@ static void f2fs_put_super(struct super_block *sb)
if (sbi->s_chksum_driver)
crypto_free_shash(sbi->s_chksum_driver);
kfree(sbi->raw_super);
+
+ destroy_percpu_info(sbi);
kfree(sbi);
}

@@ -1325,7 +1335,6 @@ int sanity_check_ckpt(struct f2fs_sb_info *sbi)
static void init_sb_info(struct f2fs_sb_info *sbi)
{
struct f2fs_super_block *raw_super = sbi->raw_super;
- int i;

sbi->log_sectors_per_block =
le32_to_cpu(raw_super->log_sectors_per_block);
@@ -1345,9 +1354,6 @@ static void init_sb_info(struct f2fs_sb_info *sbi)
sbi->cur_victim_sec = NULL_SECNO;
sbi->max_victim_search = DEF_MAX_VICTIM_SEARCH;

- for (i = 0; i < NR_COUNT_TYPE; i++)
- atomic_set(&sbi->nr_pages[i], 0);
-
sbi->dir_level = DEF_DIR_LEVEL;
sbi->interval_time[CP_TIME] = DEF_CP_INTERVAL;
sbi->interval_time[REQ_TIME] = DEF_IDLE_INTERVAL;
@@ -1363,6 +1369,18 @@ static void init_sb_info(struct f2fs_sb_info *sbi)
#endif
}

+static int init_percpu_info(struct f2fs_sb_info *sbi)
+{
+ int i, err;
+
+ for (i = 0; i < NR_COUNT_TYPE; i++) {
+ err = percpu_counter_init(&sbi->nr_pages[i], 0, GFP_KERNEL);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
/*
* Read f2fs raw super block.
* Because we have two copies of super block, so read both of them
@@ -1553,6 +1571,10 @@ try_onemore:
init_waitqueue_head(&sbi->cp_wait);
init_sb_info(sbi);

+ err = init_percpu_info(sbi);
+ if (err)
+ goto free_options;
+
/* get an inode for meta space */
sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi));
if (IS_ERR(sbi->meta_inode)) {
@@ -1755,6 +1777,7 @@ free_meta_inode:
make_bad_inode(sbi->meta_inode);
iput(sbi->meta_inode);
free_options:
+ destroy_percpu_info(sbi);
kfree(options);
free_sb_buf:
kfree(raw_super);
--
2.6.3