From owner-freebsd-hackers@FreeBSD.ORG Tue Feb 28 23:01:01 2012 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 7B764106564A; Tue, 28 Feb 2012 23:01:01 +0000 (UTC) (envelope-from artemb@gmail.com) Received: from mail-yw0-f54.google.com (mail-yw0-f54.google.com [209.85.213.54]) by mx1.freebsd.org (Postfix) with ESMTP id 21F3A8FC12; Tue, 28 Feb 2012 23:01:01 +0000 (UTC) Received: by yhgm50 with SMTP id m50so1913921yhg.13 for ; Tue, 28 Feb 2012 15:01:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=yHflomQUR2m5u6DsIUUCp9eGGZAJ6ZnZfz7PTmFCI3g=; b=Or8H64Hp19vh26wy9O8pLATYl84Q+yBMAOiSq9VmwWyKuZyn+tb9r7jdNUyZ/Ic00q paN9B4craR6BvSqH4eADfdyyk4bYhXD+kdoId3W02bw8bPL4IKEWJVh5wHE9CEXrNQAC TgIgfJABGTE+bxoaCj655D3kuMV/lehnuTGAo= MIME-Version: 1.0 Received: by 10.236.186.1 with SMTP id v1mr24618210yhm.4.1330470060627; Tue, 28 Feb 2012 15:01:00 -0800 (PST) Sender: artemb@gmail.com Received: by 10.146.159.40 with HTTP; Tue, 28 Feb 2012 15:01:00 -0800 (PST) In-Reply-To: References: <4F4C0726.6010804@FreeBSD.org> <4F4CAAC1.9060908@FreeBSD.org> Date: Tue, 28 Feb 2012 15:01:00 -0800 X-Google-Sender-Auth: tzeHgHzfzLf7HomtdMA5YJHo9U4 Message-ID: From: Artem Belevich To: Wojciech Puchar Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: freebsd-hackers@freebsd.org, Grzegorz Kulewski , Andriy Gapon Subject: Re: improving VM - questions X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Feb 2012 23:01:01 -0000 On Tue, Feb 28, 2012 at 1:06 PM, Wojciech Puchar wrote: >>>> right. but still 32 pages is 128kB, but i see 64kB I/Os in systat/vmst= at >>> >>> Right, but the comment says to not define MAX_PAGEOUT_CLUSTER to a valu= e greater >>> than 32, but you did that. =A0So all bets could be off unless you exami= ned the >>> code and know exactly what should happen in this case. >> >> I suspect it might be DFLTPHYS that splits disk i/o into 64K blocks on >> the driver level. > can i increase DFLTPHYS as well as i did with MAXPHYS without problems? Sorry, I don't have definitive answer to that. This old post has some related info: http://lists.freebsd.org/pipermail/freebsd-performance/2008-February/003311= .html Even older thread on freebsd-arch also described some concerns: http://lists.freebsd.org/pipermail/freebsd-arch/2004-January/001590.html I don't know whether the stuff above still applies to FreeBSD as it is now: --Artem