f2fs: enhance multi-threads performance

Previously, f2fs_write_data_pages has a mutex, sbi->writepages, to serialize
data writes to maximize write bandwidth, while sacrificing multi-threads
performance.
Practically, however, multi-threads environment is much more important for
users. So this patch tries to remove the mutex.

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

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 4a416e74bb2a151e0e7d2ccca4380e96a4af106e..f0a18a005bda72b35a7ac8426252388dff8dbd23 100644 (file)
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1397,7 +1397,6 @@ 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;
 
@@ -1418,13 +1417,7 @@ static int f2fs_write_data_pages(struct address_space *mapping,
 
        diff = nr_pages_to_write(sbi, DATA, wbc);
 
-       if (!S_ISDIR(inode->i_mode)) {
-               mutex_lock(&sbi->writepages);
-               locked = true;
-       }
        ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
-       if (locked)
-               mutex_unlock(&sbi->writepages);
 
        f2fs_submit_merged_bio(sbi, DATA, WRITE);
 

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 147ef316f0ff148388afe14fe14e5607b4be1870..dbe114463a182a420cf6d869d6989098e6b0c025 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -613,7 +613,6 @@ 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;
 
        struct inode_management im[MAX_INO_ENTRY];      /* manage inode cache */

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index f9dc543805d9e525c26a89ca76ec60355838220c..fc6857f378cc6b2bbe38bc6543fc23d4fedb4aff 100644 (file)
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1027,7 +1027,6 @@ try_onemore:
        sbi->raw_super = raw_super;
        sbi->raw_super_buf = raw_super_buf;
        mutex_init(&sbi->gc_mutex);
-       mutex_init(&sbi->writepages);
        mutex_init(&sbi->cp_mutex);
        init_rwsem(&sbi->node_write);
        clear_sbi_flag(sbi, SBI_POR_DOING);