f2fs: remove writepages lock

This patch removes writepages lock.
We can improve multi-threading performance.

tiobench, 32 threads, 4KB write per fsync on SSD
Before: 25.88 MB/s
After: 28.03 MB/s

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 287582e..7132b02 100644 (file)
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1443,7 +1443,6 @@ static int f2fs_write_data_pages(struct address_space *mapping,
 {
        struct inode *inode = mapping->host;
        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
-       bool locked = false;
        int ret;
        long diff;
 
@@ -1472,14 +1471,8 @@ static int f2fs_write_data_pages(struct address_space *mapping,
 
        diff = nr_pages_to_write(sbi, DATA, wbc);
 
-       if (!S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_ALL) {
-               mutex_lock(&sbi->writepages);
-               locked = true;
-       }
        ret = f2fs_write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
        f2fs_submit_merged_bio_cond(sbi, inode, NULL, 0, DATA, WRITE);
-       if (locked)
-               mutex_unlock(&sbi->writepages);
 
        remove_dirty_inode(inode);
 

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index f02a357..4365108 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -770,7 +770,6 @@ struct f2fs_sb_info {
        struct mutex cp_mutex;                  /* checkpoint procedure lock */
        struct rw_semaphore cp_rwsem;           /* blocking FS operations */
        struct rw_semaphore node_write;         /* locking node writes */
-       struct mutex writepages;                /* mutex for writepages() */
        wait_queue_head_t cp_wait;
        unsigned long last_time[MAX_TIME];      /* to store time in jiffies */
        long interval_time[MAX_TIME];           /* to store thresholds */

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 55203f6..a5b5739 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1630,7 +1630,6 @@ try_onemore:
        sbi->raw_super = raw_super;
        sbi->valid_super_block = valid_super_block;
        mutex_init(&sbi->gc_mutex);
-       mutex_init(&sbi->writepages);
        mutex_init(&sbi->cp_mutex);
        init_rwsem(&sbi->node_write);