Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753021AbZKAQ4p (ORCPT ); Sun, 1 Nov 2009 11:56:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752968AbZKAQ4o (ORCPT ); Sun, 1 Nov 2009 11:56:44 -0500 Received: from kanga.kvack.org ([205.233.56.17]:42979 "EHLO kanga.kvack.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752746AbZKAQ4n (ORCPT ); Sun, 1 Nov 2009 11:56:43 -0500 X-Greylist: delayed 1517 seconds by postgrey-1.27 at vger.kernel.org; Sun, 01 Nov 2009 11:56:43 EST Date: Sun, 1 Nov 2009 11:33:09 -0500 From: Benjamin LaHaise To: Eric Dumazet , Greg Kroah-Hartman Cc: "Eric W. Biederman" , Octavian Purdila , netdev@vger.kernel.org, Cosmin Ratiu , linux-kernel@vger.kernel.org Subject: [PATCH 2/3] sysfs directory scaling: count number of children dirs Message-ID: <20091101163309.GC7911@kvack.org> References: <20091101163130.GA7911@kvack.org> <20091101163230.GB7911@kvack.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091101163230.GB7911@kvack.org> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1757 Lines: 60 sysfs_count_nlink() is a bottleneck during mass bring up of network interfaces. Eliminate this problem by tracking the number of directories. Signed-off-by: Benjamin LaHaise diff -u b/fs/sysfs/dir.c b/fs/sysfs/dir.c --- b/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -70,6 +70,7 @@ sd->s_sibling = *pos; sd->s_sibling_prev = prev; *pos = sd; + parent_sd->s_nr_children_dir += (sysfs_type(sd) == SYSFS_DIR); // rb tree insert new = &(parent_sd->s_dir.child_rb_root.rb_node); @@ -118,6 +119,7 @@ if (sd->s_sibling) sd->s_sibling->s_sibling_prev = prev; + sd->s_parent->s_nr_children_dir -= (sysfs_type(sd) == SYSFS_DIR); sd->s_sibling_prev = NULL; rb_erase(&sd->s_rb_node, &sd->s_parent->s_dir.child_rb_root); } diff -u b/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h --- b/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -71,6 +71,8 @@ ino_t s_ino; umode_t s_mode; struct sysfs_inode_attrs *s_iattr; + + int s_nr_children_dir; }; #define SD_DEACTIVATED_BIAS INT_MIN only in patch2: unchanged: --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -191,14 +191,7 @@ static struct lock_class_key sysfs_inode_imutex_key; static int sysfs_count_nlink(struct sysfs_dirent *sd) { - struct sysfs_dirent *child; - int nr = 0; - - for (child = sd->s_dir.children; child; child = child->s_sibling) - if (sysfs_type(child) == SYSFS_DIR) - nr++; - - return nr + 2; + return sd->s_nr_children_dir + 2; } static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/