From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Herbert Subject: Re: [PATCH v3] rfs: Receive Flow Steering Date: Fri, 9 Apr 2010 06:50:44 -0700 Message-ID: References: <1270797457.2623.19.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: davem@davemloft.net, netdev@vger.kernel.org To: Eric Dumazet Return-path: Received: from smtp-out.google.com ([74.125.121.35]:4136 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750828Ab0DINuv convert rfc822-to-8bit (ORCPT ); Fri, 9 Apr 2010 09:50:51 -0400 Received: from wpaz9.hot.corp.google.com (wpaz9.hot.corp.google.com [172.24.198.73]) by smtp-out.google.com with ESMTP id o39Domcm026665 for ; Fri, 9 Apr 2010 15:50:49 +0200 Received: from pwi8 (pwi8.prod.google.com [10.241.219.8]) by wpaz9.hot.corp.google.com with ESMTP id o39Doc9x030837 for ; Fri, 9 Apr 2010 06:50:46 -0700 Received: by pwi8 with SMTP id 8so2862510pwi.29 for ; Fri, 09 Apr 2010 06:50:46 -0700 (PDT) In-Reply-To: <1270797457.2623.19.camel@edumazet-laptop> Sender: netdev-owner@vger.kernel.org List-ID: >> =A0 * @mc_ttl - Multicasting TTL >> =A0 * @is_icsk - is this an inet_connection_sock? >> @@ -124,6 +126,9 @@ struct inet_sock { >> =A0 =A0 =A0 __u16 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 cmsg_flags; >> =A0 =A0 =A0 __be16 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0inet_sport; >> =A0 =A0 =A0 __u16 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 inet_id; >> +#ifdef CONFIG_RPS >> + =A0 =A0 __u32 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 rxhash; >> +#endif > > I am a bit worried, because dirtying this cache line might hurt non R= PS > setups (if network interrupts are balanced to all cpus) > The rxhash should only be written when it changes. So as long as device or lower stack provide a consistent rxhash for a connection this should be okay. > Best place would be to put rxhash close to sk_refcnt (because we dirt= y > it to get a reference on rcu sk lookups) > In sock_common?... I don't know if we need this in every socket yet. > I believe we have a 32bits hole on 64bit arches for this :) > > > While testint latest net-nex-2.6 on my nehalem machine, I got a crash > (in RPS I am afraid...) > > I am going to correct this crash before testing RFS and let you know = the > results. Thanks for doing that. > > Thanks > > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at =A0http://vger.kernel.org/majordomo-info.html >