From owner-svn-src-head@FreeBSD.ORG Fri Sep 5 09:24:27 2014 Return-Path: Delivered-To: svn-src-head@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 78B9BC5A; Fri, 5 Sep 2014 09:24:27 +0000 (UTC) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 2D6291472; Fri, 5 Sep 2014 09:24:25 +0000 (UTC) Received: from porto.starpoint.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id MAA19169; Fri, 05 Sep 2014 12:24:03 +0300 (EEST) (envelope-from avg@FreeBSD.org) Received: from localhost ([127.0.0.1]) by porto.starpoint.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1XPpkQ-000PYs-Mg; Fri, 05 Sep 2014 12:24:02 +0300 Message-ID: <5409810E.1080705@FreeBSD.org> Date: Fri, 05 Sep 2014 12:23:26 +0300 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Steven Hartland Subject: Re: svn commit: r270759 - in head/sys: cddl/compat/opensolaris/kern cddl/compat/opensolaris/sys cddl/contrib/opensolaris/uts/common/fs/zfs vm References: <201408281950.s7SJo90I047213@svn.freebsd.org> <169C94ED141B435BACEADB04A4824717@multiplay.co.uk> <54072E20.10802@mail.lifanov.com> <2230377.GgKARkJyaG@ralph.baldwin.cx> <540778A2.3080809@mail.lifanov.com> <5407816B.9000401@FreeBSD.org> <86292055B4114529874B693EEB441CB6@multiplay.co.uk> In-Reply-To: <86292055B4114529874B693EEB441CB6@multiplay.co.uk> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Mailman-Approved-At: Fri, 05 Sep 2014 11:33:51 +0000 Cc: src-committers@FreeBSD.org, John Baldwin , Peter Wemm , Alan Cox , svn-src-all@FreeBSD.org, Dmitry Morozovsky , "Matthew D. Fuller" , Nikolai Lifanov , svn-src-head@FreeBSD.org X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Sep 2014 09:24:27 -0000 on 04/09/2014 04:18 Steven Hartland said the following: > Indeed that would be interesting, but we might find that its quite memory size > dependent given the scaling so confirming HW details would be nice too. > > I'd also be interested to know who wins the free race between the VM and ARC > when using that value. BTW, I've written a small silly program that tests for a problem that affected me in the distant past: http://people.freebsd.org/~avg/arc-vs-swap.c It gobbles almost all of the memory and then just sits on it never accessing it again. At the same time it repeatedly reads blocks of data from a large file. The idea is that eventually the unused memory should be pushed out to the swap and the ARC is allowed to grow to accommodate for the data being read. I run this program on a freshly booted system without any other applications. Prior to r270759 the system behaves as expected. Although the pace of shifting balance between the ARC and the swap-backed pages is quite slow. After r270759 and with the default tuning the ARC always sits at its minimum size. To me this is a regression. To summarize: I really appreciate the improvements that you are making here https://reviews.freebsd.org/D702 Thanks! P.S. I wish there was an easy way to make the page cache and the ARC aware of each other. -- Andriy Gapon