From owner-svn-src-head@FreeBSD.ORG Sun Sep 7 12:57:01 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 B82EAFFE; Sun, 7 Sep 2014 12:57:01 +0000 (UTC) Received: from zxy.spb.ru (zxy.spb.ru [195.70.199.98]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 6A33B1CC0; Sun, 7 Sep 2014 12:57:01 +0000 (UTC) Received: from slw by zxy.spb.ru with local (Exim 4.82 (FreeBSD)) (envelope-from ) id 1XQc1R-000Ixf-GC; Sun, 07 Sep 2014 16:56:49 +0400 Date: Sun, 7 Sep 2014 16:56:49 +0400 From: Slawa Olhovchenkov To: Andriy Gapon Subject: Re: svn commit: r270759 - in head/sys: cddl/compat/opensolaris/kern cddl/compat/opensolaris/sys cddl/contrib/opensolaris/uts/common/fs/zfs vm Message-ID: <20140907125649.GA72244@zxy.spb.ru> 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> <5409810E.1080705@FreeBSD.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5409810E.1080705@FreeBSD.org> User-Agent: Mutt/1.5.23 (2014-03-12) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: slw@zxy.spb.ru X-SA-Exim-Scanned: No (on zxy.spb.ru); SAEximRunCond expanded to false X-Mailman-Approved-At: Mon, 08 Sep 2014 20:39:38 +0000 Cc: src-committers@FreeBSD.org, John Baldwin , Peter Wemm , Alan Cox , svn-src-all@FreeBSD.org, Dmitry Morozovsky , "Matthew D. Fuller" , Steven Hartland , svn-src-head@FreeBSD.org, Nikolai Lifanov 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: Sun, 07 Sep 2014 12:57:01 -0000 On Fri, Sep 05, 2014 at 12:23:26PM +0300, Andriy Gapon wrote: > 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. I think no single way for any workload. For some workloads ARC is prefered. For some -- RSS is prefered. May be need some tunable for elastics factor ARC/RSS? PS: very bad that 'data limit' don't anymore reflect application memory consumer. and very small application can adapt to 'no memory' from system.