From owner-svn-src-all@FreeBSD.ORG Mon Dec 22 17:28:18 2014 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 ACDE6521; Mon, 22 Dec 2014 17:28:18 +0000 (UTC) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (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 1D6DB102; Mon, 22 Dec 2014 17:28:17 +0000 (UTC) Received: from tom.home (kostik@localhost [127.0.0.1]) by kib.kiev.ua (8.14.9/8.14.9) with ESMTP id sBMHSChH097539 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 22 Dec 2014 19:28:12 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.9.2 kib.kiev.ua sBMHSChH097539 Received: (from kostik@localhost) by tom.home (8.14.9/8.14.9/Submit) id sBMHSBFK097538; Mon, 22 Dec 2014 19:28:11 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Mon, 22 Dec 2014 19:28:11 +0200 From: Konstantin Belousov To: John Baldwin Subject: Re: svn commit: r276008 - in head/sys: kern sys Message-ID: <20141222172810.GY2148@kib.kiev.ua> References: <201412211332.sBLDW8VC030548@svn.freebsd.org> <20141221151425.GX2148@kib.kiev.ua> <5496F37D.5030903@FreeBSD.org> <201412220940.02509.jhb@freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201412220940.02509.jhb@freebsd.org> User-Agent: Mutt/1.5.23 (2014-03-12) X-Spam-Status: No, score=-2.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.0 X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on tom.home Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, Andriy Gapon 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: Mon, 22 Dec 2014 17:28:18 -0000 On Mon, Dec 22, 2014 at 09:40:02AM -0500, John Baldwin wrote: > On Sunday, December 21, 2014 11:21:17 am Andriy Gapon wrote: > > On 21/12/2014 17:14, Konstantin Belousov wrote: > > > On Sun, Dec 21, 2014 at 04:45:28PM +0200, Andriy Gapon wrote: > > >> On 21/12/2014 16:41, Konstantin Belousov wrote: > > >>> Or, are you asking why caching of the name could be needed for > > >>> core dump files at all ? > > >> > > >> Sort of. Why VN_OPEN_NAMECACHE is useful in the case of core dumps? > > >> What does it make better? > > > The vn_fullpath() mostly works for the core files after the change, > > > comparing with the non-working state at all before. > > > > > > > Ah, vn_fullpath(). Thank you. > > Is there something specific to core dumps that makes vn_fullpath() more > useful to have working before a process tries to open the core? (As > compared to other newly-created files) See other Rui' reply in the thread. It was done by his request. Basically, we cannot enable caching for CREATE, since operations like extracting large archive, would flush the cache. Doing it rarely and when needed is acceptable. The explained use case seems to be warranted.