On 7/21/25 10:24, Gao Xiang wrote: > > > On 2025/7/21 10:13, Chao Yu wrote: >> This patch supports to readahead more blocks in erofs_readdir(), it can >> enhance readdir performance in large direcotry. >> >> readdir test in a large directory which contains 12000 sub-files. >> >> files_per_second >> Before: 926385.54 >> After: 2380435.562 >> >> Meanwhile, let's introduces a new sysfs entry to control readahead >> bytes to provide more flexible policy for readahead of readdir(). >> - location: /sys/fs/erofs/<disk>/dir_ra_bytes >> - default value: 16384 >> - disable readahead: set the value to 0 >> >> Signed-off-by: Chao Yu <[email protected]> >> --- >> v4: >> - clean up codes and comments >> Documentation/ABI/testing/sysfs-fs-erofs | 8 ++++++++ >> fs/erofs/dir.c | 14 ++++++++++++++ >> fs/erofs/internal.h | 4 ++++ >> fs/erofs/super.c | 2 ++ >> fs/erofs/sysfs.c | 2 ++ >> 5 files changed, 30 insertions(+) >> >> diff --git a/Documentation/ABI/testing/sysfs-fs-erofs >> b/Documentation/ABI/testing/sysfs-fs-erofs >> index bf3b6299c15e..85fa56ca092c 100644 >> --- a/Documentation/ABI/testing/sysfs-fs-erofs >> +++ b/Documentation/ABI/testing/sysfs-fs-erofs >> @@ -35,3 +35,11 @@ Description: Used to set or show hardware accelerators >> in effect >> and multiple accelerators are separated by '\n'. >> Supported accelerator(s): qat_deflate. >> Disable all accelerators with an empty string (echo > accel). >> + >> +What: /sys/fs/erofs/<disk>/dir_ra_bytes >> +Date: July 2025 >> +Contact: "Chao Yu" <[email protected]> >> +Description: Used to set or show readahead bytes during readdir(), by >> + default the value is 16384. >> + >> + - 0: disable readahead. >> diff --git a/fs/erofs/dir.c b/fs/erofs/dir.c >> index 3e4b38bec0aa..99745c272b60 100644 >> --- a/fs/erofs/dir.c >> +++ b/fs/erofs/dir.c >> @@ -47,8 +47,12 @@ static int erofs_readdir(struct file *f, struct >> dir_context *ctx) >> struct inode *dir = file_inode(f); >> struct erofs_buf buf = __EROFS_BUF_INITIALIZER; >> struct super_block *sb = dir->i_sb; >> + struct file_ra_state *ra = &f->f_ra; >> unsigned long bsz = sb->s_blocksize; >> unsigned int ofs = erofs_blkoff(sb, ctx->pos); >> + pgoff_t ra_pages = DIV_ROUND_UP_POW2( >> + EROFS_I_SB(dir)->dir_ra_bytes, PAGE_SIZE); >> + pgoff_t nr_pages = DIV_ROUND_UP_POW2(dir->i_size, PAGE_SIZE); >> int err = 0; >> bool initial = true; >> @@ -63,6 +67,16 @@ static int erofs_readdir(struct file *f, struct >> dir_context *ctx) >> break; >> } >> + /* readahead blocks to enhance performance in large directory */ >> + if (ra_pages) { >> + pgoff_t idx = DIV_ROUND_UP(ctx->pos, PAGE_SIZE); > > Can we use DIV_ROUND_UP_POW2 here too? If it's okay, > I will update the patch manually when applied.
Xiang, Yeah, looks fine to me. Please go ahead to update it while applying, thanks for your help. :) Thanks, > > Otherwise it looks good to me, > Reviewed-by: Gao Xiang <[email protected]> > > Thanks, > Gao Xiang
