From mboxrd@z Thu Jan 1 00:00:00 1970 From: Octavian Purdila Subject: Re: [net-next-2.6 PATCH] net: fast consecutive name allocation Date: Sat, 14 Nov 2009 02:14:21 +0200 Message-ID: <200911140214.21493.opurdila@ixiacom.com> References: <200911130701.14847.opurdila@ixiacom.com> <200911130720.19671.opurdila@ixiacom.com> <20091113160445.7a3538ef@nehalam> Mime-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Stephen Hemminger Return-path: Received: from ixro-out-rtc.ixiacom.com ([92.87.192.98]:19345 "EHLO ixro-ex1.ixiacom.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757252AbZKNARW (ORCPT ); Fri, 13 Nov 2009 19:17:22 -0500 In-Reply-To: <20091113160445.7a3538ef@nehalam> Sender: netdev-owner@vger.kernel.org List-ID: On Saturday 14 November 2009 02:04:45 you wrote: > On Fri, 13 Nov 2009 07:20:19 +0200 > > Octavian Purdila wrote: > > On Friday 13 November 2009 07:01:14 you wrote: > > > This patch speeds up the network device name allocation for the case > > > where a significant number of devices of the same type are created > > > consecutively. > > > > > > Tests performed on a PPC750 @ 800Mhz machine with per device sysctl > > > and sysfs entries disabled: > > > > > > Without the patch With the patch > > > > > > real 0m 43.43s real 0m 0.49s > > > user 0m 0.00s user 0m 0.00s > > > sys 0m 43.43s sys 0m 0.48s > > Since the main overhead here is building the bitmap table used in the > name scan. Why not mantain the bitmap table between calls by > implementing a rbtree with prefix -> bitmap. > The tree would have to be limited and per namespace but then you > could handle the general case of adding a device, then its vlans, > then another device, ... > I'll do that ! That was my original intent but I thought it would be too much bloat :) But I see your point, even if it is more complex, its more useful. Thanks, tavi