From owner-freebsd-hackers@freebsd.org Thu Oct 3 08:40:35 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 9692212DFD7 for ; Thu, 3 Oct 2019 08:40:35 +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 46kRKZ4YMDz3KCx for ; Thu, 3 Oct 2019 08:40:34 +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 x938eONT097049 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Thu, 3 Oct 2019 11:40:27 +0300 (EEST) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua x938eONT097049 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id x938eLcN097014; Thu, 3 Oct 2019 11:40:21 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Thu, 3 Oct 2019 11:40:21 +0300 From: Konstantin Belousov To: Bruce Evans Cc: Sebastian Huber , FreeBSD Subject: Re: Why is tc_get_timecount() called two times in tc_init()? Message-ID: <20191003084021.GI44691@kib.kiev.ua> References: <0e27fb3e-0f60-68e1-dbba-f17c3d91c332@embedded-brains.de> <20191002140040.GA44691@kib.kiev.ua> <20191003013314.O2151@besplex.bde.org> <20191002163946.GE44691@kib.kiev.ua> <20191003030837.C2787@besplex.bde.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191003030837.C2787@besplex.bde.org> 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: 46kRKZ4YMDz3KCx 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 [-1.00 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; DMARC_POLICY_SOFTFAIL(0.10)[gmail.com : No valid SPF, No valid DKIM,none]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; FREEMAIL_FROM(0.00)[gmail.com]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; HAS_XAW(0.00)[]; R_SPF_SOFTFAIL(0.00)[~all]; IP_SCORE_FREEMAIL(0.00)[]; MIME_TRACE(0.00)[0:+]; TO_DN_ALL(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; IP_SCORE(0.00)[ip: (-2.66), ipnet: 2001:470::/32(-4.53), asn: 6939(-3.34), country: US(-0.05)]; FREEMAIL_TO(0.00)[optusnet.com.au]; 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]; SUBJECT_ENDS_QUESTION(1.00)[]; 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: Thu, 03 Oct 2019 08:40:35 -0000 On Thu, Oct 03, 2019 at 03:12:26AM +1000, Bruce Evans wrote: > On Wed, 2 Oct 2019, Konstantin Belousov wrote: > > > On Thu, Oct 03, 2019 at 02:25:46AM +1000, Bruce Evans wrote: > >> On Wed, 2 Oct 2019, Konstantin Belousov wrote: > > So the conclusion is that the second call can be removed, am I right ? > > Yes. > > All tc_get_timecount() functions should be checked for doing sufficient > initialization in one call (so that deltas for subsequent calls are > correct). This should be it. But, is even a single call to tc_get_timecount() needed for "warmup" ? diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c index 382d139617d..28d0d738a58 100644 --- a/sys/dev/acpica/acpi.c +++ b/sys/dev/acpica/acpi.c @@ -3191,7 +3191,6 @@ acpi_resync_clock(struct acpi_softc *sc) * Warm up timecounter again and reset system clock. */ (void)timecounter->tc_get_timecount(timecounter); - (void)timecounter->tc_get_timecount(timecounter); inittodr(time_second + sc->acpi_sleep_delay); } diff --git a/sys/dev/acpica/acpi_timer.c b/sys/dev/acpica/acpi_timer.c index 34a832089a2..d768397a785 100644 --- a/sys/dev/acpica/acpi_timer.c +++ b/sys/dev/acpica/acpi_timer.c @@ -274,7 +274,6 @@ acpi_timer_resume_handler(struct timecounter *newtc) "restoring timecounter, %s -> %s\n", tc->tc_name, newtc->tc_name); (void)newtc->tc_get_timecount(newtc); - (void)newtc->tc_get_timecount(newtc); timecounter = newtc; } } diff --git a/sys/dev/xen/control/control.c b/sys/dev/xen/control/control.c index 98ab5bf3a6b..1e132f4d866 100644 --- a/sys/dev/xen/control/control.c +++ b/sys/dev/xen/control/control.c @@ -303,7 +303,6 @@ xctrl_suspend() * Warm up timecounter again and reset system clock. */ timecounter->tc_get_timecount(timecounter); - timecounter->tc_get_timecount(timecounter); inittodr(time_second); #ifdef EARLY_AP_STARTUP diff --git a/sys/kern/kern_tc.c b/sys/kern/kern_tc.c index 9920a9a9304..847fbbbf35d 100644 --- a/sys/kern/kern_tc.c +++ b/sys/kern/kern_tc.c @@ -1257,7 +1257,6 @@ tc_init(struct timecounter *tc) tc->tc_frequency < timecounter->tc_frequency) return; (void)tc->tc_get_timecount(tc); - (void)tc->tc_get_timecount(tc); timecounter = tc; } @@ -1519,7 +1518,6 @@ sysctl_kern_timecounter_hardware(SYSCTL_HANDLER_ARGS) /* Warm up new timecounter. */ (void)newtc->tc_get_timecount(newtc); - (void)newtc->tc_get_timecount(newtc); timecounter = newtc; @@ -2011,7 +2009,6 @@ inittimecounter(void *dummy) /* warm up new timecounter (again) and get rolling. */ (void)timecounter->tc_get_timecount(timecounter); - (void)timecounter->tc_get_timecount(timecounter); mtx_lock_spin(&tc_setclock_mtx); tc_windup(NULL); mtx_unlock_spin(&tc_setclock_mtx);