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/

Reply via email to