From owner-freebsd-hackers@FreeBSD.ORG Sun Sep 19 08:42:07 2010 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 988AA106566C; Sun, 19 Sep 2010 08:42:07 +0000 (UTC) (envelope-from avg@freebsd.org) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 426FF8FC0A; Sun, 19 Sep 2010 08:42:05 +0000 (UTC) Received: from porto.topspin.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 LAA19605; Sun, 19 Sep 2010 11:42:04 +0300 (EEST) (envelope-from avg@freebsd.org) Received: from localhost.topspin.kiev.ua ([127.0.0.1]) by porto.topspin.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1OxFTH-000GWC-Dm; Sun, 19 Sep 2010 11:42:03 +0300 Message-ID: <4C95CCDA.7010007@freebsd.org> Date: Sun, 19 Sep 2010 11:42:02 +0300 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.2.9) Gecko/20100918 Lightning/1.0b2 Thunderbird/3.1.4 MIME-Version: 1.0 To: Jeff Roberson References: <4C93236B.4050906@freebsd.org> <4C935F56.4030903@freebsd.org> <4C95C804.1010701@freebsd.org> In-Reply-To: X-Enigmail-Version: 1.1.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Andre Oppermann , Jeff Roberson , Robert Watson , freebsd-hackers@freebsd.org Subject: Re: zfs + uma 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: Sun, 19 Sep 2010 08:42:07 -0000 on 19/09/2010 11:27 Jeff Roberson said the following: > I don't like this because even with very large buffers you can still have high > enough turnover to require per-cpu caching. Kip specifically added UMA support > to address this issue in zfs. If you have allocations which don't require > per-cpu caching and are very large why even use UMA? Good point. Right now I am running with 4 items/bucket limit for items larger than 32KB. -- Andriy Gapon