Use first character as a hint for /proc/$PID lookup. Currently it takes one spinlock and search through dozens of misc proc entries which can not match /proc/$PID.
Signed-off-by: Alexey Dobriyan <adobri...@gmail.com> --- fs/proc/root.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -199,10 +199,17 @@ static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags) { - if (!proc_lookup(dir, dentry, flags)) - return NULL; - - return proc_pid_lookup(dir, dentry, flags); + const char c = dentry->d_name.name[0]; + struct dentry *rv; + + if ('0' <= c && c <= '9') { + rv = proc_pid_lookup(dir, dentry, flags); + if (rv) + rv = proc_lookup(dir, dentry, flags); + } else { + rv = proc_lookup(dir, dentry, flags); + } + return rv; } static int proc_root_readdir(struct file *file, struct dir_context *ctx) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/