From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH next-next-2.6] netdev: better dev_name_hash Date: Sun, 25 Oct 2009 21:43:57 -0700 Message-ID: <20091025214357.666350d2@nehalam> References: <200910252158.53921.opurdila@ixiacom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Octavian Purdila Return-path: Received: from mail.vyatta.com ([76.74.103.46]:43102 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753300AbZJZEn7 (ORCPT ); Mon, 26 Oct 2009 00:43:59 -0400 In-Reply-To: <200910252158.53921.opurdila@ixiacom.com> Sender: netdev-owner@vger.kernel.org List-ID: On Sun, 25 Oct 2009 21:58:53 +0200 Octavian Purdila wrote: > > The current dev_name_hash is not very good at spreading entries when a > large number of interfaces of the same type (e.g. ethXXXXX) are used. > > Here are some performance numbers for creating 16000 dummy interfaces with > and without the patch (with per device sysctl entries disabled) > > With patch Without patch > > real 0m 2.27s real 0m 4.32s > user 0m 0.00s user 0m 0.00s > sys 0m 1.13s sys 0m 2.16s > > Signed-off-by: Octavian Purdila > --- > net/core/dev.c | 8 +++++++- > 1 files changed, 7 insertions(+), 1 deletions(-) My $.02 would for fixing full name hash because other usages would benefit as well. Inventing special case for network devices seems unnecessary. --