From owner-svn-src-head@FreeBSD.ORG Tue Nov 18 22:44:00 2014 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 1FCA17CC; Tue, 18 Nov 2014 22:44:00 +0000 (UTC) Received: from mail-la0-x22c.google.com (mail-la0-x22c.google.com [IPv6:2a00:1450:4010:c03::22c]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id AFA07E94; Tue, 18 Nov 2014 22:43:59 +0000 (UTC) Received: by mail-la0-f44.google.com with SMTP id ge10so1065136lab.31 for ; Tue, 18 Nov 2014 14:43:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=6scIQWERWwSw7TNqc1ekEUsDYDbsarhcxMkVJqgnbzc=; b=g8Vu2TSZF9mD7e6VhZMvKlLy9Ea3mK8eg9qdXQFALQ1MfYiYy6ETLQNhH5glc2sogI jh1t8oe0mdROchvuipINWfawwSUjNVVI2joebxbbA/+Ojw5b7wy1+Ccpwlwsa8QS9HmW VHNdmNqBgx0G9YBiYLwmftSSjLjRWovRjv6JKVMEtfGLVziPhMB6HHF8SaRkeP2FYN04 P1lupyIQrohzutjwFLCn2sIu/g4kFcLVNF30ucp1BmKwUwC9eDrpMxZtoQUuSNBoN1e0 qm2i5APnI3OWH3E1HKCcCj5EzSoV+gR6z4UX9t58lx/aCllxuSjzrQ5yLl/1TKb3T998 DYag== MIME-Version: 1.0 X-Received: by 10.152.88.100 with SMTP id bf4mr1905001lab.74.1416350637781; Tue, 18 Nov 2014 14:43:57 -0800 (PST) Sender: mahrens@gmail.com Received: by 10.112.210.4 with HTTP; Tue, 18 Nov 2014 14:43:57 -0800 (PST) In-Reply-To: <20141118220030.GA31347@zxy.spb.ru> References: <201411181840.sAIIe2C7094558@svn.freebsd.org> <20141118220030.GA31347@zxy.spb.ru> Date: Tue, 18 Nov 2014 14:43:57 -0800 X-Google-Sender-Auth: zQlPeRCmxtIsvcojNBVBHYRpEqw Message-ID: Subject: Re: svn commit: r274673 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs From: Matthew Ahrens To: Slawa Olhovchenkov Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.18-1 Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, "src-committers@freebsd.org" , Xin LI 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: Tue, 18 Nov 2014 22:44:00 -0000 On Tue, Nov 18, 2014 at 2:00 PM, Slawa Olhovchenkov wrote: > On Tue, Nov 18, 2014 at 06:40:02PM +0000, Xin LI wrote: > > > Author: delphij > > Date: Tue Nov 18 18:40:01 2014 > > New Revision: 274673 > > URL: https://svnweb.freebsd.org/changeset/base/274673 > > > > Log: > > Allow tuning zfs_max_recordsize via loader tunable. Tuning is NOT > > recommended. > > This is not tuning, this is simple guard. > And can be safe changed (incrased, at the least) in any time. > For some workload optimal is maximum, i.e. 16MB. > May be better comment: increasing this value required strong > understaning after-effects of increasing memory consumption and > bulk data transfers. (sorry for english) > I agree -- setting recordsize to 16MB is an easy way to make performance suck if you don't know what you're doing. But it isn't dangerous from a correctness point of view. --matt > > > Requested by: Slawa Olhovchenkov > > MFC after: 2 weeks > > Thanks, can you allow RW? > > > Modified: > > head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dataset.c > > > > Modified: > head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dataset.c > > > ============================================================================== > > --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dataset.c > Tue Nov 18 18:03:40 2014 (r274672) > > +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dataset.c > Tue Nov 18 18:40:01 2014 (r274673) > > @@ -51,6 +51,8 @@ > > #include > > #include > > > > +SYSCTL_DECL(_vfs_zfs); > > + > > /* > > * The SPA supports block sizes up to 16MB. However, very large blocks > > * can have an impact on i/o latency (e.g. tying up a spinning disk for > > @@ -61,6 +63,9 @@ > > * of this setting. > > */ > > int zfs_max_recordsize = 1 * 1024 * 1024; > > +SYSCTL_INT(_vfs_zfs, OID_AUTO, max_recordsize, CTLFLAG_RDTUN, > > + &zfs_max_recordsize, 0, > > + "Maximum block size. Expect dragons when tuning this."); > > > > #define SWITCH64(x, y) \ > > { \ > > _______________________________________________ > > svn-src-all@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/svn-src-all > > To unsubscribe, send any mail to "svn-src-all-unsubscribe@freebsd.org" > >