From owner-dev-commits-src-main@freebsd.org Sat Jul 31 12:48:40 2021 Return-Path: Delivered-To: dev-commits-src-main@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 A9D9365BBAB; Sat, 31 Jul 2021 12:48:40 +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 4GcPFz4212z4S0F; Sat, 31 Jul 2021 12:48:39 +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 16VCmVYo080354 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Sat, 31 Jul 2021 15:48:34 +0300 (EEST) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua 16VCmVYo080354 Received: (from kostik@localhost) by tom.home (8.16.1/8.16.1/Submit) id 16VCmV1q080353; Sat, 31 Jul 2021 15:48:31 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Sat, 31 Jul 2021 15:48:31 +0300 From: Konstantin Belousov To: Alexander Motin Cc: src-committers@freebsd.org, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org Subject: Re: git: 74f80bc1af2f - main - coretemp(4): Switch to smp_rendezvous_cpus(). Message-ID: References: <202107300326.16U3QGHR070204@gitrepo.freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202107300326.16U3QGHR070204@gitrepo.freebsd.org> 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=3.4.5 X-Spam-Checker-Version: SpamAssassin 3.4.5 (2021-03-20) on tom.home X-Rspamd-Queue-Id: 4GcPFz4212z4S0F 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 [2.62 / 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]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; HAS_XAW(0.00)[]; R_SPF_SOFTFAIL(0.00)[~all:c]; NEURAL_SPAM_MEDIUM(0.99)[0.990]; TO_DN_SOME(0.00)[]; NEURAL_SPAM_SHORT(1.00)[1.000]; NEURAL_SPAM_LONG(0.63)[0.629]; 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)[dev-commits-src-all,dev-commits-src-main]; DMARC_POLICY_SOFTFAIL(0.10)[gmail.com : No valid SPF, No valid DKIM,none] X-BeenThere: dev-commits-src-main@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for the main branch of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 31 Jul 2021 12:48:40 -0000 On Fri, Jul 30, 2021 at 03:26:16AM +0000, Alexander Motin wrote: > The branch main has been updated by mav: > > URL: https://cgit.FreeBSD.org/src/commit/?id=74f80bc1af2ffd56ec290f610c80e46f768731a0 > > commit 74f80bc1af2ffd56ec290f610c80e46f768731a0 > Author: Alexander Motin > AuthorDate: 2021-07-30 03:16:22 +0000 > Commit: Alexander Motin > CommitDate: 2021-07-30 03:26:10 +0000 > > coretemp(4): Switch to smp_rendezvous_cpus(). > > Use of smp_rendezvous_cpus() instead of sched_bind() allows to not > block indefinitely if target CPU is running some thread with higher > priority, while all we need is single rdmsr/wrmsr instruction call. > I guess it should also be much cheaper than full thread migration. > > MFC after: 2 weeks > Sponsored by: iXsystems, Inc. > --- > sys/dev/coretemp/coretemp.c | 59 ++++++++++++++++++++++++++++----------------- > 1 file changed, 37 insertions(+), 22 deletions(-) > > diff --git a/sys/dev/coretemp/coretemp.c b/sys/dev/coretemp/coretemp.c > index 884ed6309f0e..53a2434254f6 100644 > --- a/sys/dev/coretemp/coretemp.c > +++ b/sys/dev/coretemp/coretemp.c > @@ -42,7 +42,7 @@ __FBSDID("$FreeBSD$"); > #include > #include > #include /* for curthread */ > -#include > +#include > #include > #include > > @@ -310,14 +310,32 @@ coretemp_detach(device_t dev) > return (0); > } > > +struct coretemp_args { > + u_int msr; > + uint64_t val; > +}; > + > +static void > +coretemp_rdmsr(void *arg) > +{ > + struct coretemp_args *args = arg; > + > + args->val = rdmsr(args->msr); > +} > + > +static void > +coretemp_wrmsr(void *arg) > +{ > + struct coretemp_args *args = arg; > + > + wrmsr(args->msr, args->val); > +} We have x86_msr_op(). It covers coretemp_wrmsr(), and with slight change of the interface would also handle the functionality of coretemp_rdmsr(). > + > static uint64_t > coretemp_get_thermal_msr(int cpu) > { > - uint64_t msr; > - > - thread_lock(curthread); > - sched_bind(curthread, cpu); > - thread_unlock(curthread); > + struct coretemp_args args; > + cpuset_t cpus; > > /* > * The digital temperature reading is located at bit 16 > @@ -329,27 +347,24 @@ coretemp_get_thermal_msr(int cpu) > * The temperature is computed by subtracting the temperature > * reading by Tj(max). > */ > - msr = rdmsr(MSR_THERM_STATUS); > - > - thread_lock(curthread); > - sched_unbind(curthread); > - thread_unlock(curthread); > - > - return (msr); > + args.msr = MSR_THERM_STATUS; > + CPU_SETOF(cpu, &cpus); > + smp_rendezvous_cpus(cpus, smp_no_rendezvous_barrier, coretemp_rdmsr, > + smp_no_rendezvous_barrier, &args); > + return (args.val); > } > > static void > coretemp_clear_thermal_msr(int cpu) > { > - thread_lock(curthread); > - sched_bind(curthread, cpu); > - thread_unlock(curthread); > - > - wrmsr(MSR_THERM_STATUS, 0); > - > - thread_lock(curthread); > - sched_unbind(curthread); > - thread_unlock(curthread); > + struct coretemp_args args; > + cpuset_t cpus; > + > + args.msr = MSR_THERM_STATUS; > + args.val = 0; > + CPU_SETOF(cpu, &cpus); > + smp_rendezvous_cpus(cpus, smp_no_rendezvous_barrier, coretemp_wrmsr, > + smp_no_rendezvous_barrier, &args); > } > > static int