From owner-freebsd-fs@freebsd.org Wed Aug 29 09:45:57 2018 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 004221083B24; Wed, 29 Aug 2018 09:45:56 +0000 (UTC) (envelope-from rainer@ultra-secure.de) Received: from connect.ultra-secure.de (connect.ultra-secure.de [88.198.71.201]) by mx1.freebsd.org (Postfix) with ESMTP id 313E384C73; Wed, 29 Aug 2018 09:45:55 +0000 (UTC) (envelope-from rainer@ultra-secure.de) Received: (Haraka outbound); Wed, 29 Aug 2018 11:45:49 +0200 Authentication-Results: connect.ultra-secure.de; auth=pass (login); spf=none smtp.mailfrom=ultra-secure.de Received-SPF: None (connect.ultra-secure.de: domain of ultra-secure.de does not designate 127.0.0.10 as permitted sender) receiver=connect.ultra-secure.de; identity=mailfrom; client-ip=127.0.0.10; helo=connect.ultra-secure.de; envelope-from= Received: from connect.ultra-secure.de (webmail [127.0.0.10]) by connect.ultra-secure.de (Haraka/2.6.2-toaster) with ESMTPSA id D9C3E06D-0A03-4E0E-BF2A-36955DEE3DEE.1 envelope-from (authenticated bits=0) (version=TLSv1/SSLv3 cipher=AES256-SHA verify=NO); Wed, 29 Aug 2018 11:45:46 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 29 Aug 2018 11:45:45 +0200 From: rainer@ultra-secure.de To: lev@freebsd.org Cc: Yamagi Burmeister , freebsd-fs@freebsd.org, MacCrest@gmail.com, owner-freebsd-fs@freebsd.org Subject: Re: ZFS (ARC) performance regression in r321610 In-Reply-To: <3c6f8c96-6ac9-7257-c8c0-8be2063a7c19@FreeBSD.org> References: <20180827154727.80f92fff9bbc931b37928d43@yamagi.org> <3c6f8c96-6ac9-7257-c8c0-8be2063a7c19@FreeBSD.org> Message-ID: <1c816966fbe698f0497df231139f9a05@ultra-secure.de> X-Sender: rainer@ultra-secure.de User-Agent: Roundcube Webmail/1.2.0 X-Haraka-GeoIP: --, , NaNkm X-Haraka-GeoIP-Received: X-Haraka-p0f: os="undefined undefined" link_type="undefined" distance=undefined total_conn=undefined shared_ip=Y X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on spamassassin X-Spam-Level: X-Spam-Status: No, score=-2.9 required=5.0 tests=ALL_TRUSTED,BAYES_00 autolearn=ham autolearn_force=no version=3.4.1 X-Haraka-Karma: score: 6, good: 678, bad: 0, connections: 684, history: 678, pass:all_good, relaying X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Aug 2018 09:45:57 -0000 Am 2018-08-27 16:19, schrieb Lev Serebryakov: > On 27.08.2018 16:47, Yamagi Burmeister wrote: > >> With this program I was able to bisect the source and identify commit >> r321610 (MFV r318946: 8021 ARC buf data scatter-ization) as the >> culprit: >> https://svnweb.freebsd.org/base?view=revision&revision=321610 > You could try to set "zfs_abd_scatter_enabled = 0" via kgdb and repeat > tests to be sure, that this code is a problem. > > BTW, it is not clear, that FreeBSD needs this at all. Hi, how exactly do I do this? Best Regards Rainer