From owner-freebsd-hackers@freebsd.org Wed Oct 2 14:00:50 2019 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 F162212FD82 for ; Wed, 2 Oct 2019 14:00:50 +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 46jyTY4nBXz4SK0; Wed, 2 Oct 2019 14:00:49 +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 x92E0e3O035242 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Wed, 2 Oct 2019 17:00:43 +0300 (EEST) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua x92E0e3O035242 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id x92E0enp035241; Wed, 2 Oct 2019 17:00:40 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Wed, 2 Oct 2019 17:00:40 +0300 From: Konstantin Belousov To: Sebastian Huber Cc: FreeBSD , bde@freebsd.org Subject: Re: Why is tc_get_timecount() called two times in tc_init()? Message-ID: <20191002140040.GA44691@kib.kiev.ua> References: <0e27fb3e-0f60-68e1-dbba-f17c3d91c332@embedded-brains.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <0e27fb3e-0f60-68e1-dbba-f17c3d91c332@embedded-brains.de> User-Agent: Mutt/1.12.2 (2019-09-21) 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=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on tom.home X-Rspamd-Queue-Id: 46jyTY4nBXz4SK0 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 [-0.99 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.99)[-0.992,0]; RCVD_TLS_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; FREEMAIL_FROM(0.00)[gmail.com]; IP_SCORE(0.00)[ip: (-2.72), ipnet: 2001:470::/32(-4.53), asn: 6939(-3.34), country: US(-0.05)]; MIME_GOOD(-0.10)[text/plain]; HAS_XAW(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; R_SPF_SOFTFAIL(0.00)[~all:c]; IP_SCORE_FREEMAIL(0.00)[]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; SUBJECT_ENDS_QUESTION(1.00)[]; 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]; FREEMAIL_ENVFROM(0.00)[gmail.com]; DMARC_POLICY_SOFTFAIL(0.10)[gmail.com : No valid SPF, No valid DKIM,none] 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, 02 Oct 2019 14:00:51 -0000 On Tue, Oct 01, 2019 at 01:11:18PM +0200, Sebastian Huber wrote: > Hello, > > since this commit > > https://github.com/freebsd/freebsd/commit/307f787e5a7f > It is not very useful to pass github hashes around. I think that the addition of the second tc_get_timecount() was done earlier, in r95530, and there it has semi-useful comment + /* Warm up new timecounter. */ + (void)newtc->tc_get_timecount(newtc); + (void)newtc->tc_get_timecount(newtc); The commit message is not helpful at all. I do not see a timecounter which would need two get_timecount() calls to start working properly now, but I can imagine that at time it was. I added Bruce to Cc: to may be get more context and explanation. > tc_get_timecount() is called two times in tc_init(). > > /* > * Initialize a new timecounter and possibly use it. > */ > void > tc_init(struct timecounter *tc) > { > [...] > if (tc->tc_quality == timecounter->tc_quality && > tc->tc_frequency < timecounter->tc_frequency) > return; > (void)tc->tc_get_timecount(tc); > (void)tc->tc_get_timecount(tc); > timecounter = tc; > } > > What is the reason for this procedure? > > -- > Sebastian Huber, embedded brains GmbH > > Address : Dornierstr. 4, D-82178 Puchheim, Germany > Phone : +49 89 189 47 41-16 > Fax : +49 89 189 47 41-09 > E-Mail : sebastian.huber@embedded-brains.de > PGP : Public key available on request. > > Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. > _______________________________________________ > 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"