On Wed 22-07-20 15:58:49, Amir Goldstein wrote:
> We can get inode by dereferenceing dentry->d_inode, but that may have
> performance impact in the fast path of non watched file.
>
> Kernel test robot reported a performance regression in concurrent open
> workload, so maybe that can fix it.
>
> Reported-by: kernel test robot <rong.a.chen@xxxxxxxxx>
> Fixes: c738fbabb0ff ("fsnotify: fold fsnotify() call into fsnotify_parent()")
> Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
I didn't take this patch because honestly, I don't think the extra argument
is worth it unless we can prove real performance benefit...
Honza
> ---
> include/linux/fsnotify.h | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
> index d9b26c6552ee..4a9b2f5b819b 100644
> --- a/include/linux/fsnotify.h
> +++ b/include/linux/fsnotify.h
> @@ -49,10 +49,9 @@ static inline void fsnotify_inode(struct inode *inode, __u32 mask)
>
> /* Notify this dentry's parent about a child's events. */
> static inline int fsnotify_parent(struct dentry *dentry, __u32 mask,
> - const void *data, int data_type)
> + const void *data, int data_type,
> + struct inode *inode)
> {
> - struct inode *inode = d_inode(dentry);
> -
> if (S_ISDIR(inode->i_mode)) {
> mask |= FS_ISDIR;
>
> @@ -77,7 +76,8 @@ static inline int fsnotify_parent(struct dentry *dentry, __u32 mask,
> */
> static inline void fsnotify_dentry(struct dentry *dentry, __u32 mask)
> {
> - fsnotify_parent(dentry, mask, d_inode(dentry), FSNOTIFY_EVENT_INODE);
> + fsnotify_parent(dentry, mask, d_inode(dentry), FSNOTIFY_EVENT_INODE,
> + d_inode(dentry));
> }
>
> static inline int fsnotify_file(struct file *file, __u32 mask)
> @@ -87,7 +87,8 @@ static inline int fsnotify_file(struct file *file, __u32 mask)
> if (file->f_mode & FMODE_NONOTIFY)
> return 0;
>
> - return fsnotify_parent(path->dentry, mask, path, FSNOTIFY_EVENT_PATH);
> + return fsnotify_parent(path->dentry, mask, path, FSNOTIFY_EVENT_PATH,
> + file_inode(file));
> }
>
> /* Simple call site for access decisions */
> --
> 2.17.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
