From owner-svn-src-head@freebsd.org Fri Oct 30 15:55:39 2020 Return-Path: Delivered-To: svn-src-head@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 1DBDC455A05; Fri, 30 Oct 2020 15:55:39 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4CN6NB0yv9z49WW; Fri, 30 Oct 2020 15:55:37 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.16.1/8.16.1) with ESMTPS id 09UFtTHt043241 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Fri, 30 Oct 2020 17:55:32 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua 09UFtTHt043241 Received: (from kostik@localhost) by tom.home (8.16.1/8.16.1/Submit) id 09UFtTpk043240; Fri, 30 Oct 2020 17:55:29 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Fri, 30 Oct 2020 17:55:29 +0200 From: Konstantin Belousov To: Mateusz Guzik Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r367165 - head/sys/fs/tmpfs Message-ID: <20201030155529.GF2654@kib.kiev.ua> References: <202010301407.09UE7Phw060731@repo.freebsd.org> <20201030143851.GE2654@kib.kiev.ua> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,FREEMAIL_FROM, NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on tom.home X-Rspamd-Queue-Id: 4CN6NB0yv9z49WW X-Spamd-Bar: + Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=gmail.com (policy=none); spf=softfail (mx1.freebsd.org: 2001:470:d5e7:1::1 is neither permitted nor denied by domain of kostikbel@gmail.com) smtp.mailfrom=kostikbel@gmail.com X-Spamd-Result: default: False [1.08 / 15.00]; ARC_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; RCVD_TLS_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; FREEMAIL_FROM(0.00)[gmail.com]; NEURAL_SPAM_SHORT(0.59)[0.588]; MIME_GOOD(-0.10)[text/plain]; HAS_XAW(0.00)[]; R_SPF_SOFTFAIL(0.00)[~all:c]; NEURAL_SPAM_MEDIUM(0.03)[0.032]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; NEURAL_SPAM_LONG(0.46)[0.459]; FREEMAIL_TO(0.00)[gmail.com]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:6939, ipnet:2001:470::/32, country:US]; RCVD_COUNT_TWO(0.00)[2]; MAILMAN_DEST(0.00)[svn-src-all,svn-src-head]; DMARC_POLICY_SOFTFAIL(0.10)[gmail.com : No valid SPF, No valid DKIM,none] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.33 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: Fri, 30 Oct 2020 15:55:39 -0000 On Fri, Oct 30, 2020 at 04:42:39PM +0100, Mateusz Guzik wrote: > On 10/30/20, Konstantin Belousov wrote: > > On Fri, Oct 30, 2020 at 03:08:32PM +0100, Mateusz Guzik wrote: > >> On 10/30/20, Mateusz Guzik wrote: > >> > Author: mjg > >> > Date: Fri Oct 30 14:07:25 2020 > >> > New Revision: 367165 > >> > URL: https://svnweb.freebsd.org/changeset/base/367165 > >> > > >> > Log: > >> > tmpfs: change tmpfs dirent zone into a malloc type > >> > > >> > It is 64 bytes. > >> > > >> > >> Right now malloc has only power-of-2 zones but I'm looking into > >> changing that. The allocator itself trivially extends to multiply of > >> 16, but stat collection needs reworking. > > > > Either commit message or follow-up do not explain why stopping using > > zone for dirents is useful. Intuition says exactly reverse, dirents > > on tmpfs are allocation-intensive typically. > > > > Off hand the only reasons to use a dedicated zones that I see are: > - use of any of the routines on object creation/destruction > - non-standard flags like NOFREE > - SMR > - high expected allocated count with sizes poorly fit for malloc - Visibility of allocation rate and memory consumption - Detection of leak on zone destruction (tmpfs unmount) > > Since malloc itself is implemented on top of zones, the difference > before/after the patch is that now it can re-use the pre-existing 64 > byte buckets instead of creating its own copy. > > The above follow up was to address potential comments about the size > changing from 64 -- with better malloc granularity this wont be a big > deal. Also note tmpfs already uses malloc to store names. Is it 64 on all arches, on only on LP64 ? I think the later, and then this additionally hits 32bit arches. > > If anything in my opinion the kernel has unnecessary zones (like the > vnode poll one I patched prior to this). For this one I agree, it is low-profile alloc type.