From owner-svn-src-all@FreeBSD.ORG Sat Mar 21 21:22:45 2015 Return-Path: Delivered-To: svn-src-all@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 DA772832; Sat, 21 Mar 2015 21:22:45 +0000 (UTC) Received: from woozle.rinet.ru (woozle.rinet.ru [195.54.192.68]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 54A53D0B; Sat, 21 Mar 2015 21:22:44 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by woozle.rinet.ru (8.14.5/8.14.5) with ESMTP id t2LLGMeW065924; Sun, 22 Mar 2015 00:16:22 +0300 (MSK) (envelope-from marck@rinet.ru) Date: Sun, 22 Mar 2015 00:16:22 +0300 (MSK) From: Dmitry Morozovsky To: Konstantin Belousov Subject: Re: svn commit: r280323 - head/sys/kern In-Reply-To: <20150321210810.GT2379@kib.kiev.ua> Message-ID: References: <201503211501.t2LF1Kj8052521@svn.freebsd.org> <20150321210341.GC15857@lonesome.com> <20150321210810.GT2379@kib.kiev.ua> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) X-NCC-RegID: ru.rinet X-OpenPGP-Key-ID: 6B691B03 MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (woozle.rinet.ru [0.0.0.0]); Sun, 22 Mar 2015 00:17:30 +0300 (MSK) Cc: svn-src-head@freebsd.org, Mark Linimon , svn-src-all@freebsd.org, src-committers@freebsd.org X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 21 Mar 2015 21:22:46 -0000 On Sat, 21 Mar 2015, Konstantin Belousov wrote: > > > Somewhat modernize the SysV shm code: > > > > Interesting. > > > > Is my understanding correct that postgres still uses shm? If so, > > has someone benchmarked the speedup? > > Yes, some versions of Postgres still use SysV shm. To be clarified: IIUC, *all* contemporary versions of PostgreSQL do use SHM for shatrd buffers (as PgSQL use process-per-connection model) > But note that the code changed only works during shared segment creation and > teardown. Page faults are handled by the same VM code as it was before. > > In other words, I expect that nothing changes WRT benchmarks. On the other hand, I also do not see anything that could change benchmarks significally -- Sincerely, D.Marck [DM5020, MCK-RIPE, DM3-RIPN] [ FreeBSD committer: marck@FreeBSD.org ] ------------------------------------------------------------------------ *** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- marck@rinet.ru *** ------------------------------------------------------------------------