From owner-freebsd-mips@FreeBSD.ORG  Sat Sep  7 20:39:38 2013
Return-Path: <owner-freebsd-mips@FreeBSD.ORG>
Delivered-To: freebsd-mips@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTP id CFF98BD0;
 Sat,  7 Sep 2013 20:39:38 +0000 (UTC)
 (envelope-from adrian.chadd@gmail.com)
Received: from mail-wi0-x22a.google.com (mail-wi0-x22a.google.com
 [IPv6:2a00:1450:400c:c05::22a])
 (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits))
 (No client certificate requested)
 by mx1.freebsd.org (Postfix) with ESMTPS id 208C72439;
 Sat,  7 Sep 2013 20:39:37 +0000 (UTC)
Received: by mail-wi0-f170.google.com with SMTP id cb5so2073806wib.3
 for <multiple recipients>; Sat, 07 Sep 2013 13:39:36 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113;
 h=mime-version:sender:in-reply-to:references:date:message-id:subject
 :from:to:cc:content-type;
 bh=Eogs7PtTl8wK6UKeDC50CHhbbeGcRYkfUewmC8zCO0Y=;
 b=Vsg/5MZiCV1xgikUzKlyAKI0crtBaVDmpF4AVfg0reayRrBYtc2S9W5AYNIK9mXLNz
 Rxto51P1ffodJHz7aVwDbFcCWgsPw+ebEU9YWQf1yRanhotjJQhSZrfpOg69mdUcO+55
 +YdYYPgcjarmPcEe1NygtjH/BtZZXjRZDSJ5eu38nvApolsRivvTKhXu+MPVw6LXzLbz
 XLQXU2gQbOQMv0F2PR4Jn8nS8oox3v+yoA7vTJ1NRZlEkc372Xvsa2U//DWtgwq+EWE3
 9RgAZTOm7jaQi0cdLgnSQ4QcbkcPpBIhXb5khn+MRtz3NIAwAx9AilmxX3R27v9A5qca
 Zd1w==
MIME-Version: 1.0
X-Received: by 10.180.211.206 with SMTP id ne14mr3132494wic.30.1378586376497; 
 Sat, 07 Sep 2013 13:39:36 -0700 (PDT)
Sender: adrian.chadd@gmail.com
Received: by 10.216.73.133 with HTTP; Sat, 7 Sep 2013 13:39:36 -0700 (PDT)
In-Reply-To: <1378583762.1111.512.camel@revolution.hippie.lan>
References: <CALCpEUHoAS2RRyO7JVOeSKWKiss9vZmN+xA1BDpwHDpkEYcjEA@mail.gmail.com>
 <CAJ-VmomAjsU+nc=4AEdSn5gDhspc2YVrDtPophJvmee1kSTYog@mail.gmail.com>
 <9CBFAD35-D651-4E28-BEBB-DC3717F38567@bsdimp.com>
 <CALCpEUHh9o-scuoj_p-MGMZKn2d_Bbhtf8djV8MsLeOF8+KG9A@mail.gmail.com>
 <1378583762.1111.512.camel@revolution.hippie.lan>
Date: Sat, 7 Sep 2013 13:39:36 -0700
X-Google-Sender-Auth: dO_aVyQDWHdX9IOWuPlMNNMaolo
Message-ID: <CAJ-Vmon03Es2WJp+0p-_XuTdfqc8=daO8w1Kp4M=t0aNBoAruA@mail.gmail.com>
Subject: Re: mbuf autotuning effect
From: Adrian Chadd <adrian@freebsd.org>
To: Ian Lepore <ian@freebsd.org>
Content-Type: text/plain; charset=ISO-8859-1
X-Content-Filtered-By: Mailman/MimeDel 2.1.14
Cc: FreeBSD Net <freebsd-net@freebsd.org>,
 "freebsd-mips@freebsd.org" <freebsd-mips@freebsd.org>
X-BeenThere: freebsd-mips@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Porting FreeBSD to MIPS <freebsd-mips.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-mips>,
 <mailto:freebsd-mips-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-mips>
List-Post: <mailto:freebsd-mips@freebsd.org>
List-Help: <mailto:freebsd-mips-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-mips>,
 <mailto:freebsd-mips-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 07 Sep 2013 20:39:39 -0000

On 7 September 2013 12:56, Ian Lepore <ian@freebsd.org> wrote:


> I think the part of this that strikes me as strange is calling 20% of
> physical memory used for network buffers a "very low value".  It seems
> outrageously high to me.   I'd be pissed if that much memory got wasted
> on network buffers on one of our $work platforms with so little memory.
>
> So the fact that you think it's crazy-low and I think it's crazy-high
> may be a sign that it's auto-tuned to a reasonable compromise, and in
> both our cases the right fix would be to use the available knobs to tune
> things for our particular uses.
>

Well, which limit is actually being hit here? 20% of 32mb is still a lot of
memory buffers..

Now, for sizing up the needed buffers for wifi:

assuming 512 tx, 512 rx buffers for two ath NICs.

another 512+512 buffers for each arge NICs.

So, 4096 mbufs here, 2k each, so ~ 8mb of RAM.

Amusing..



-adrian