From owner-freebsd-hackers@freebsd.org Wed Jan 8 14:18:19 2020 Return-Path: Delivered-To: freebsd-hackers@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 2F5571F012B for ; Wed, 8 Jan 2020 14:18:19 +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) server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 47tBDV2S3nz4Xn0 for ; Wed, 8 Jan 2020 14:18:18 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id 008EIAdU008176 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Wed, 8 Jan 2020 16:18:13 +0200 (EET) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua 008EIAdU008176 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id 008EIAIv008175; Wed, 8 Jan 2020 16:18:10 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Wed, 8 Jan 2020 16:18:10 +0200 From: Konstantin Belousov To: Wojciech Puchar Cc: Gary Jennejohn , Hans Petter Selasky , "freebsd-hackers@freebsd.org" , Rick Macklem Subject: Re: maximum MAXBSIZE Message-ID: <20200108141810.GX23031@kib.kiev.ua> References: <20200108105136.0d54ebce@ernst.home> 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=3.4.3 X-Spam-Checker-Version: SpamAssassin 3.4.3 (2019-12-06) on tom.home X-Rspamd-Queue-Id: 47tBDV2S3nz4Xn0 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 [-2.00 / 15.00]; ARC_NA(0.00)[]; TO_DN_EQ_ADDR_SOME(0.00)[]; DMARC_POLICY_SOFTFAIL(0.10)[gmail.com : No valid SPF, No valid DKIM,none]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; FREEMAIL_FROM(0.00)[gmail.com]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; MIME_TRACE(0.00)[0:+]; HAS_XAW(0.00)[]; R_SPF_SOFTFAIL(0.00)[~all:c]; RCPT_COUNT_FIVE(0.00)[5]; IP_SCORE_FREEMAIL(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; IP_SCORE(0.00)[ip: (-3.05), ipnet: 2001:470::/32(-4.67), asn: 6939(-3.57), country: US(-0.05)]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:6939, ipnet:2001:470::/32, country:US]; FREEMAIL_CC(0.00)[gmail.com]; RCVD_TLS_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 08 Jan 2020 14:18:19 -0000 On Wed, Jan 08, 2020 at 02:52:57PM +0100, Wojciech Puchar wrote: > sorry i made a mistake - i change MAXPHYS not MAXBSIZE. > > 16MB works for now without problems MAXPHYS 16MB means that sizeof(struct buf) is around 32K (16K on 32bit). > > On Wed, 8 Jan 2020, Gary Jennejohn wrote: > > > On Tue, 7 Jan 2020 22:47:54 +0000 > > Rick Macklem wrote: > > > > > Hans Petter Selasky wrote: > > > > On 2020-01-07 22:12, Wojciech Puchar wrote: > > > > > default MAXBSIZE is 128kB. badly low for todays magnetic disks. > > > > > > > > > > i have it set to 2MB on all computers that have magnetic disks. Great > > > > > improvement with large files. especially when more than one are > > > > > read/wrote in parallel. And no problems experienced > > > > > > > > > > But for optimal performance MAXBSIZE should be transfered in few times > > > > > longer than average seek time. todays disk do 200-250MB/s so 2MB is > > > > > transfered below 10ms. > > > > > > > > > > 8-16MB seems like good choice. is there any reason not to set it that high? > > > > > > > > Old disk may not support it, especially USB 1.0/2.0 disks. > > > I also thought it was limited to MAXPHYS, but maybe I'm only thinking of the NFS > > > specific case? > > > > > > > There's a comment in param.h that it should not exceed MAXPHYS to be > > on the safe side. How old that comment is I can't say and that may > > not be the case today. > > > > MAXBSIZE is only 64KiB in my param.h. > > > > I have to agree with HPS. There are many old bridge-chips still in > > use and problems with a large MAXBSIZE might occur. It's certainly > > not uncommon to see capacity limitations - I have a docking station > > which can't see more than 3TB. > > > > -- > > Gary Jennejohn > > > > > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org"