From owner-freebsd-net@FreeBSD.ORG Thu May 10 23:39:24 2012 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5A983106566B; Thu, 10 May 2012 23:39:24 +0000 (UTC) (envelope-from seanbru@yahoo-inc.com) Received: from mrout3.yahoo.com (mrout3.yahoo.com [216.145.54.173]) by mx1.freebsd.org (Postfix) with ESMTP id 201998FC17; Thu, 10 May 2012 23:39:24 +0000 (UTC) Received: from [IPv6:::1] (proxy6.corp.yahoo.com [216.145.48.19]) by mrout3.yahoo.com (8.14.4/8.14.4/y.out) with ESMTP id q4ANd8KP044174; Thu, 10 May 2012 16:39:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=yahoo-inc.com; s=cobra; t=1336693149; bh=ib2OU8jqEIH4TLqIpXTMatrx1hgB/slsArFtDclQ6Eo=; h=Subject:From:To:Cc:In-Reply-To:References:Content-Type:Date: Message-ID:Mime-Version:Content-Transfer-Encoding; b=EugIqFPL+eJ1KSAS9cqRZP+jqGX4NB5mB4HZ6gp3wChSO6XZQ+Eye7H2IJ5yAcE2F yuo0uXlivV9iZbrGkqcIQoXKaFoXznOCVOWvR7kMOQhbo2gNAZ7WMU1JJPsMGwD9vy u98lodbZBXHDRSA6e9AxAYaZU6wHxv0oWOR9T/m4= From: Sean Bruno To: John Baldwin In-Reply-To: <1336538165.28313.1.camel@powernoodle-l7> References: <1335312667.11564.13.camel@powernoodle-l7.corp.yahoo.com> <201204250932.21378.jhb@freebsd.org> <1335382225.2722.6.camel@powernoodle-l7.corp.yahoo.com> <1336084418.3077.21.camel@powernoodle-l7.corp.yahoo.com> <1336538165.28313.1.camel@powernoodle-l7> Content-Type: text/plain; charset="UTF-8" Date: Thu, 10 May 2012 16:39:08 -0700 Message-ID: <1336693148.4179.11.camel@powernoodle-l7> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 FreeBSD GNOME Team Port Content-Transfer-Encoding: 7bit Cc: "freebsd-net@freebsd.org" , Jack Vogel Subject: Re: igb(4) Pondering a bind to cpu patch X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 10 May 2012 23:39:24 -0000 On Tue, 2012-05-08 at 21:36 -0700, Sean Bruno wrote: > On Thu, 2012-05-03 at 15:33 -0700, Sean Bruno wrote: > > > > On Wed, 2012-04-25 at 12:30 -0700, Sean Bruno wrote: > > > On Wed, 2012-04-25 at 06:32 -0700, John Baldwin wrote: > > > > CPU IDs are not guaranteed to be dense. However, you can use > > > > CPU_FIRST() and > > > > CPU_NEXT() with your static global instead. > > > > > > > Ah, does CPU_NEXT() reset to 0 when it reaches the end of its list of > > > CPUs? > > > > > > > Ah, I see. So, yeah, here's a v2 of the patch that does "the right" > > thing with non-sparse cpus, mulitple queues, and mulitple physical > > interfaces. > > > > http://people.freebsd.org/~sbruno/if_igb.c.txt > > > > > > > > > OTOH, if igb were to just leave the interrupts alone instead of > > > > binding them > > > > by hand, they would get round-robin assigned among available cores > > > > already. I > > > > think in this case the best approach might be to add a tunable to > > > > disable > > > > igb's manual binding and instead let the default system round-robin > > > > be > > > > preserved. > > > > > > also, yes. Why *are* we binding to CPUs in the first place? Are we > > > afraid that the scheduler won't do the right thing and we're trying to > > > work around some unknown performance issue ? > > > > > > Sean > > > > > > > Still haven't seen a good reason to bind the queues by default in the > > first place. > > > > Sean > > > > > If there's no objection, I'll commit this in the morning. > > Sean > This was committed. Let me know if there's anything hinky with it.