This patch introduces a sysfs interface readdir_ra to enable/disable
readaheading inode block in f2fs_readdir. When readdir_ra is enabled,
it improves the performance of "readdir + stat".
For 300,000 files:
time find /data/test > /dev/null
disable readdir_ra: 1m25.69s real 0m01.94s user 0m50.80s system
enable readdir_ra: 0m18.55s real 0m00.44s user 0m15.39s system
Signed-off-by: Sheng Yong <shengyo...@huawei.com>
---
Documentation/ABI/testing/sysfs-fs-f2fs | 6 ++++++
fs/f2fs/dir.c | 4 ++++
fs/f2fs/f2fs.h | 1 +
fs/f2fs/sysfs.c | 2 ++
4 files changed, 13 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs
b/Documentation/ABI/testing/sysfs-fs-f2fs
index a7799c2fca28..d870b5514d15 100644
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -186,3 +186,9 @@ Date: August 2017
Contact: "Jaegeuk Kim" <jaeg...@kernel.org>
Description:
Controls sleep time of GC urgent mode
+
+What: /sys/fs/f2fs/<disk>/readdir_ra
+Date: November 2017
+Contact: "Sheng Yong" <shengyo...@huawei.com>
+Description:
+ Controls readahead inode block in readdir.
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 2d98d877c09d..724304dc6143 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -798,6 +798,7 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct
f2fs_dentry_ptr *d,
unsigned int bit_pos;
struct f2fs_dir_entry *de = NULL;
struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
+ struct f2fs_sb_info *sbi = F2FS_I_SB(d->inode);
bit_pos = ((unsigned long)ctx->pos % d->max);
@@ -836,6 +837,9 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct
f2fs_dentry_ptr *d,
le32_to_cpu(de->ino), d_type))
return 1;
+ if (sbi->readdir_ra == 1)
+ ra_node_page(sbi, le32_to_cpu(de->ino));
+
bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
ctx->pos = start_pos + bit_pos;
}
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index ca6b0c9bc621..a269d795ba7c 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1095,6 +1095,7 @@ struct f2fs_sb_info {
int dir_level; /* directory level */
int inline_xattr_size; /* inline xattr size */
unsigned int trigger_ssr_threshold; /* threshold to trigger ssr */
+ int readdir_ra; /* readahead inode in readdir */
block_t user_block_count; /* # of user blocks */
block_t total_valid_block_count; /* # of valid blocks */
diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 9835348b6e5d..93c3364250dd 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -299,6 +299,7 @@ F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, dir_level, dir_level);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, cp_interval, interval_time[CP_TIME]);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, idle_interval, interval_time[REQ_TIME]);
F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, iostat_enable, iostat_enable);
+F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, readdir_ra, readdir_ra);
#ifdef CONFIG_F2FS_FAULT_INJECTION
F2FS_RW_ATTR(FAULT_INFO_RATE, f2fs_fault_info, inject_rate, inject_rate);
F2FS_RW_ATTR(FAULT_INFO_TYPE, f2fs_fault_info, inject_type, inject_type);
@@ -346,6 +347,7 @@ static struct attribute *f2fs_attrs[] = {
ATTR_LIST(cp_interval),
ATTR_LIST(idle_interval),
ATTR_LIST(iostat_enable),
+ ATTR_LIST(readdir_ra),
#ifdef CONFIG_F2FS_FAULT_INJECTION
ATTR_LIST(inject_rate),
ATTR_LIST(inject_type),
--
2.11.0
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