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Received: from dhcp-077-249-017-003.chello.nl ([77.249.17.3] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1o0fgN-007Vf8-Ah; Mon, 13 Jun 2022 08:44:23 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id D73DB302D9E; Mon, 13 Jun 2022 10:44:22 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id BB85B200C72F2; Mon, 13 Jun 2022 10:44:22 +0200 (CEST) Date: Mon, 13 Jun 2022 10:44:22 +0200 From: Peter Zijlstra To: Jacob Pan Cc: rth@twiddle.net, ink@jurassic.park.msu.ru, mattst88@gmail.com, vgupta@kernel.org, linux@armlinux.org.uk, ulli.kroll@googlemail.com, linus.walleij@linaro.org, shawnguo@kernel.org, Sascha Hauer , kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, tony@atomide.com, khilman@kernel.org, catalin.marinas@arm.com, will@kernel.org, guoren@kernel.org, bcain@quicinc.com, chenhuacai@kernel.org, kernel@xen0n.name, geert@linux-m68k.org, sammy@sammy.net, monstr@monstr.eu, tsbogend@alpha.franken.de, dinguyen@kernel.org, jonas@southpole.se, stefan.kristiansson@saunalahti.fi, shorne@gmail.com, James.Bottomley@hansenpartnership.com, deller@gmx.de, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, ysato@users.sourceforge.jp, dalias@libc.org, davem@davemloft.net, richard@nod.at, anton.ivanov@cambridgegreys.com, johannes@sipsolutions.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, namhyung@kernel.org, jgross@suse.com, srivatsa@csail.mit.edu, amakhalov@vmware.com, pv-drivers@vmware.com, boris.ostrovsky@oracle.com, chris@zankel.net, jcmvbkbc@gmail.com, rafael@kernel.org, lenb@kernel.org, pavel@ucw.cz, gregkh@linuxfoundation.org, mturquette@baylibre.com, sboyd@kernel.org, daniel.lezcano@linaro.org, lpieralisi@kernel.org, sudeep.holla@arm.com, agross@kernel.org, bjorn.andersson@linaro.org, anup@brainfault.org, thierry.reding@gmail.com, jonathanh@nvidia.com, Arnd Bergmann , yury.norov@gmail.com, andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk, rostedt@goodmis.org, pmladek@suse.com, senozhatsky@chromium.org, john.ogness@linutronix.de, paulmck@kernel.org, frederic@kernel.org, quic_neeraju@quicinc.com, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, joel@joelfernandes.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, jpoimboe@kernel.org, linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-perf-users@vger.kernel.org, virtualization@lists.linux-foundation.org, xen-devel@lists.xenproject.org, linux-xtensa@linux-xtensa.org, linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, linux-clk@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-tegra@vger.kernel.org, linux-arch@vger.kernel.org, rcu@vger.kernel.org Subject: Re: [PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE Message-ID: References: <20220608142723.103523089@infradead.org> <20220608144516.172460444@infradead.org> <20220609164921.5e61711d@jacob-builder> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220609164921.5e61711d@jacob-builder> X-BeenThere: linux-snps-arc@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux on Synopsys ARC Processors List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-snps-arc" Errors-To: linux-snps-arc-bounces+linux-snps-arc=archiver.kernel.org@lists.infradead.org On Thu, Jun 09, 2022 at 04:49:21PM -0700, Jacob Pan wrote: > Hi Peter, > > On Wed, 08 Jun 2022 16:27:27 +0200, Peter Zijlstra > wrote: > > > Commit c227233ad64c ("intel_idle: enable interrupts before C1 on > > Xeons") wrecked intel_idle in two ways: > > > > - must not have tracing in idle functions > > - must return with IRQs disabled > > > > Additionally, it added a branch for no good reason. > > > > Fixes: c227233ad64c ("intel_idle: enable interrupts before C1 on Xeons") > > Signed-off-by: Peter Zijlstra (Intel) > > --- > > drivers/idle/intel_idle.c | 48 > > +++++++++++++++++++++++++++++++++++----------- 1 file changed, 37 > > insertions(+), 11 deletions(-) > > > > --- a/drivers/idle/intel_idle.c > > +++ b/drivers/idle/intel_idle.c > > @@ -129,21 +137,37 @@ static unsigned int mwait_substates __in > > * > > * Must be called under local_irq_disable(). > > */ > nit: this comment is no long true, right? It still is, all the idle routines are called with interrupts disabled, but must also exit with interrupts disabled. If the idle method requires interrupts to be enabled, it must be sure to disable them again before returning. Given all the RCU/tracing concerns it must use raw_local_irq_*() for this though. _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D37B2C43334 for ; Mon, 13 Jun 2022 08:45:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240250AbiFMIp1 (ORCPT ); Mon, 13 Jun 2022 04:45:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240320AbiFMIpG (ORCPT ); Mon, 13 Jun 2022 04:45:06 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB7CB20192; 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Mon, 13 Jun 2022 10:44:22 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id BB85B200C72F2; Mon, 13 Jun 2022 10:44:22 +0200 (CEST) Date: Mon, 13 Jun 2022 10:44:22 +0200 From: Peter Zijlstra To: Jacob Pan Cc: rth@twiddle.net, ink@jurassic.park.msu.ru, mattst88@gmail.com, vgupta@kernel.org, linux@armlinux.org.uk, ulli.kroll@googlemail.com, linus.walleij@linaro.org, shawnguo@kernel.org, Sascha Hauer , kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, tony@atomide.com, khilman@kernel.org, catalin.marinas@arm.com, will@kernel.org, guoren@kernel.org, bcain@quicinc.com, chenhuacai@kernel.org, kernel@xen0n.name, geert@linux-m68k.org, sammy@sammy.net, monstr@monstr.eu, tsbogend@alpha.franken.de, dinguyen@kernel.org, jonas@southpole.se, stefan.kristiansson@saunalahti.fi, shorne@gmail.com, James.Bottomley@hansenpartnership.com, deller@gmx.de, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, ysato@users.sourceforge.jp, dalias@libc.org, davem@davemloft.net, richard@nod.at, anton.ivanov@cambridgegreys.com, johannes@sipsolutions.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, namhyung@kernel.org, jgross@suse.com, srivatsa@csail.mit.edu, amakhalov@vmware.com, pv-drivers@vmware.com, boris.ostrovsky@oracle.com, chris@zankel.net, jcmvbkbc@gmail.com, rafael@kernel.org, lenb@kernel.org, pavel@ucw.cz, gregkh@linuxfoundation.org, mturquette@baylibre.com, sboyd@kernel.org, daniel.lezcano@linaro.org, lpieralisi@kernel.org, sudeep.holla@arm.com, agross@kernel.org, bjorn.andersson@linaro.org, anup@brainfault.org, thierry.reding@gmail.com, jonathanh@nvidia.com, Arnd Bergmann , yury.norov@gmail.com, andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk, rostedt@goodmis.org, pmladek@suse.com, senozhatsky@chromium.org, john.ogness@linutronix.de, paulmck@kernel.org, frederic@kernel.org, quic_neeraju@quicinc.com, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, joel@joelfernandes.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, jpoimboe@kernel.org, linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-perf-users@vger.kernel.org, virtualization@lists.linux-foundation.org, xen-devel@lists.xenproject.org, linux-xtensa@linux-xtensa.org, linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, linux-clk@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-tegra@vger.kernel.org, linux-arch@vger.kernel.org, rcu@vger.kernel.org Subject: Re: [PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE Message-ID: References: <20220608142723.103523089@infradead.org> <20220608144516.172460444@infradead.org> <20220609164921.5e61711d@jacob-builder> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220609164921.5e61711d@jacob-builder> Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org On Thu, Jun 09, 2022 at 04:49:21PM -0700, Jacob Pan wrote: > Hi Peter, > > On Wed, 08 Jun 2022 16:27:27 +0200, Peter Zijlstra > wrote: > > > Commit c227233ad64c ("intel_idle: enable interrupts before C1 on > > Xeons") wrecked intel_idle in two ways: > > > > - must not have tracing in idle functions > > - must return with IRQs disabled > > > > Additionally, it added a branch for no good reason. > > > > Fixes: c227233ad64c ("intel_idle: enable interrupts before C1 on Xeons") > > Signed-off-by: Peter Zijlstra (Intel) > > --- > > drivers/idle/intel_idle.c | 48 > > +++++++++++++++++++++++++++++++++++----------- 1 file changed, 37 > > insertions(+), 11 deletions(-) > > > > --- a/drivers/idle/intel_idle.c > > +++ b/drivers/idle/intel_idle.c > > @@ -129,21 +137,37 @@ static unsigned int mwait_substates __in > > * > > * Must be called under local_irq_disable(). > > */ > nit: this comment is no long true, right? It still is, all the idle routines are called with interrupts disabled, but must also exit with interrupts disabled. If the idle method requires interrupts to be enabled, it must be sure to disable them again before returning. Given all the RCU/tracing concerns it must use raw_local_irq_*() for this though. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CBB0EC43334 for ; Mon, 13 Jun 2022 08:45:09 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 830D040911; Mon, 13 Jun 2022 08:45:09 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 1EaDcVAa1YRM; Mon, 13 Jun 2022 08:45:08 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp2.osuosl.org (Postfix) with ESMTPS id 263D34090E; Mon, 13 Jun 2022 08:45:08 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id ED4F7C0039; 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Mon, 13 Jun 2022 10:44:22 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id BB85B200C72F2; Mon, 13 Jun 2022 10:44:22 +0200 (CEST) Date: Mon, 13 Jun 2022 10:44:22 +0200 From: Peter Zijlstra To: Jacob Pan Subject: Re: [PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE Message-ID: References: <20220608142723.103523089@infradead.org> <20220608144516.172460444@infradead.org> <20220609164921.5e61711d@jacob-builder> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220609164921.5e61711d@jacob-builder> Cc: juri.lelli@redhat.com, rafael@kernel.org, benh@kernel.crashing.org, linus.walleij@linaro.org, bsegall@google.com, guoren@kernel.org, pavel@ucw.cz, agordeev@linux.ibm.com, linux-arch@vger.kernel.org, vincent.guittot@linaro.org, mpe@ellerman.id.au, chenhuacai@kernel.org, linux-acpi@vger.kernel.org, agross@kernel.org, geert@linux-m68k.org, linux-imx@nxp.com, catalin.marinas@arm.com, xen-devel@lists.xenproject.org, mattst88@gmail.com, mturquette@baylibre.com, sammy@sammy.net, pmladek@suse.com, linux-pm@vger.kernel.org, jiangshanlai@gmail.com, Sascha Hauer , linux-um@lists.infradead.org, acme@kernel.org, tglx@linutronix.de, linux-omap@vger.kernel.org, dietmar.eggemann@arm.com, rth@twiddle.net, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, senozhatsky@chromium.org, svens@linux.ibm.com, jolsa@kernel.org, paulus@samba.org, mark.rutland@arm.com, linux-ia64@vger.kernel.org, dave.hansen@linux.intel.com, virtualization@lists.linux-foundation.org, James.Bottomley@hansenpartnership.com, jcmvbkbc@gmail.com, thierry.reding@gmail.com, kernel@xen0n.name, quic_neeraju@quicinc.com, linux-s390@vger.kernel.org, vschneid@redhat.com, john.ogness@linutronix.de, ysato@users.sourceforge.jp, linux-sh@vger.kernel.org, festevam@gmail.com, deller@gmx.de, daniel.lezcano@linaro.org, jonathanh@nvidia.com, mathieu.desnoyers@efficios.com, frederic@kernel.org, lenb@kernel.org, linux-xtensa@linux-xtensa.org, kernel@pengutronix.de, gor@linux.ibm.com, linux-arm-msm@vger.kernel.org, linux-alpha@vger.kernel.org, linux-m68k@lists.linux-m68k.org, shorne@gmail.com, linux-arm-kernel@lists.infradead.org, chris@zankel.net, sboyd@kernel.org, dinguyen@kernel.org, bristot@redhat.com, alexander.shishkin@linux.intel.com, lpieralisi@kernel.org, linux@rasmusvillemoes.dk, joel@joelfernandes.org, will@kernel.org, boris.ostrovsky@oracle.com, khilman@kernel.org, linux-csky@vger.kernel.org, pv-drivers@vmware.com, linux-snps-arc@lists.infradead.org, mgorman@suse.de, Arnd Bergmann , ulli.kroll@googlemail.com, vgupta@kernel.org, linux-clk@vger.kernel.org, josh@joshtriplett.org, rostedt@goodmis.org, rcu@vger.kernel.org, bp@alien8.de, bcain@quicinc.com, tsbogend@alpha.franken.de, linux-parisc@vger.kernel.org, sudeep.holla@arm.com, shawnguo@kernel.org, davem@davemloft.net, dalias@libc.org, tony@atomide.com, amakhalov@vmware.com, bjorn.andersson@linaro.org, hpa@zytor.com, sparclinux@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-riscv@lists.infradead.org, anton.ivanov@cambridgegreys.com, jonas@southpole.se, yury.norov@gmail.com, richard@nod.at, x86@kernel.org, linux@armlinux.org.uk, mingo@redhat.com, aou@eecs.berkeley.edu, paulmck@kernel.org, hca@linux.ibm.com, stefan.kristiansson@saunalahti.fi, openrisc@lists.librecores.org, paul.walmsley@sifive.com, linux-tegra@vger.kernel.org, namhyung@kernel.org, andriy.shevchenko@linux.intel.com, jpoimboe@kernel.org, jgross@suse.com, monstr@monstr.eu, linux-mips@vger.kernel.org, palmer@dabbelt.com, anup@brainfault.org, ink@jurassic.park.msu.ru, johannes@sipsolutions.net, linuxppc-dev@lists.ozlabs.org X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" On Thu, Jun 09, 2022 at 04:49:21PM -0700, Jacob Pan wrote: > Hi Peter, > > On Wed, 08 Jun 2022 16:27:27 +0200, Peter Zijlstra > wrote: > > > Commit c227233ad64c ("intel_idle: enable interrupts before C1 on > > Xeons") wrecked intel_idle in two ways: > > > > - must not have tracing in idle functions > > - must return with IRQs disabled > > > > Additionally, it added a branch for no good reason. > > > > Fixes: c227233ad64c ("intel_idle: enable interrupts before C1 on Xeons") > > Signed-off-by: Peter Zijlstra (Intel) > > --- > > drivers/idle/intel_idle.c | 48 > > +++++++++++++++++++++++++++++++++++----------- 1 file changed, 37 > > insertions(+), 11 deletions(-) > > > > --- a/drivers/idle/intel_idle.c > > +++ b/drivers/idle/intel_idle.c > > @@ -129,21 +137,37 @@ static unsigned int mwait_substates __in > > * > > * Must be called under local_irq_disable(). > > */ > nit: this comment is no long true, right? It still is, all the idle routines are called with interrupts disabled, but must also exit with interrupts disabled. If the idle method requires interrupts to be enabled, it must be sure to disable them again before returning. Given all the RCU/tracing concerns it must use raw_local_irq_*() for this though. _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0B7A2C43334 for ; Mon, 13 Jun 2022 11:33:26 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4LM8Zr3xn2z3fKP for ; Mon, 13 Jun 2022 21:33:24 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; secure) header.d=infradead.org header.i=@infradead.org header.a=rsa-sha256 header.s=desiato.20200630 header.b=jHY41vel; 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Mon, 13 Jun 2022 10:44:22 +0200 (CEST) Date: Mon, 13 Jun 2022 10:44:22 +0200 From: Peter Zijlstra To: Jacob Pan Subject: Re: [PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE Message-ID: References: <20220608142723.103523089@infradead.org> <20220608144516.172460444@infradead.org> <20220609164921.5e61711d@jacob-builder> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220609164921.5e61711d@jacob-builder> X-Mailman-Approved-At: Mon, 13 Jun 2022 21:27:22 +1000 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: juri.lelli@redhat.com, rafael@kernel.org, linus.walleij@linaro.org, bsegall@google.com, guoren@kernel.org, pavel@ucw.cz, agordeev@linux.ibm.com, srivatsa@csail.mit.edu, linux-arch@vger.kernel.org, vincent.guittot@linaro.org, chenhuacai@kernel.org, linux-acpi@vger.kernel.org, agross@kernel.org, geert@linux-m68k.org, linux-imx@nxp.com, catalin.marinas@arm.com, xen-devel@lists.xenproject.org, mattst88@gmail.com, borntraeger@linux.ibm.com, mturquette@baylibre.com, sammy@sammy.net, pmladek@suse.com, linux-pm@vger.kernel.org, jiangshanlai@gmail.com, Sascha Hauer , linux-um@lists.infradead.org, acme@kernel.org, tglx@linutronix.de, linux-omap@vger.kernel.org, dietmar.eggemann@arm.com, rth@twiddle.net, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, senozhatsky@chromium.org, svens@linux.ibm.com, jolsa@kernel.org, paulus@samba.org, mark.rutland@arm.com, linux-ia64@vger.kernel.org, dave.hansen@linux.intel.com, virtualizatio n@lists.linux-foundation.org, James.Bottomley@hansenpartnership.com, jcmvbkbc@gmail.com, thierry.reding@gmail.com, kernel@xen0n.name, quic_neeraju@quicinc.com, linux-s390@vger.kernel.org, vschneid@redhat.com, john.ogness@linutronix.de, ysato@users.sourceforge.jp, linux-sh@vger.kernel.org, festevam@gmail.com, deller@gmx.de, daniel.lezcano@linaro.org, jonathanh@nvidia.com, mathieu.desnoyers@efficios.com, frederic@kernel.org, lenb@kernel.org, linux-xtensa@linux-xtensa.org, kernel@pengutronix.de, gor@linux.ibm.com, linux-arm-msm@vger.kernel.org, linux-alpha@vger.kernel.org, linux-m68k@lists.linux-m68k.org, shorne@gmail.com, linux-arm-kernel@lists.infradead.org, chris@zankel.net, sboyd@kernel.org, dinguyen@kernel.org, bristot@redhat.com, alexander.shishkin@linux.intel.com, lpieralisi@kernel.org, linux@rasmusvillemoes.dk, joel@joelfernandes.org, will@kernel.org, boris.ostrovsky@oracle.com, khilman@kernel.org, linux-csky@vger.kernel.org, pv-drivers@vmware.com, linux-snps-arc@lists.infradea d.org, mgorman@suse.de, Arnd Bergmann , ulli.kroll@googlemail.com, vgupta@kernel.org, linux-clk@vger.kernel.org, josh@joshtriplett.org, rostedt@goodmis.org, rcu@vger.kernel.org, bp@alien8.de, bcain@quicinc.com, tsbogend@alpha.franken.de, linux-parisc@vger.kernel.org, sudeep.holla@arm.com, shawnguo@kernel.org, davem@davemloft.net, dalias@libc.org, tony@atomide.com, amakhalov@vmware.com, bjorn.andersson@linaro.org, hpa@zytor.com, sparclinux@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-riscv@lists.infradead.org, anton.ivanov@cambridgegreys.com, jonas@southpole.se, yury.norov@gmail.com, richard@nod.at, x86@kernel.org, linux@armlinux.org.uk, mingo@redhat.com, aou@eecs.berkeley.edu, paulmck@kernel.org, hca@linux.ibm.com, stefan.kristiansson@saunalahti.fi, openrisc@lists.librecores.org, paul.walmsley@sifive.com, linux-tegra@vger.kernel.org, namhyung@kernel.org, andriy.shevchenko@linux.intel.com, jpoimboe@kernel.org, jgross@suse.com, monstr@monstr.eu, linux-mips@vger.kernel.org, palmer@dabbelt.com, anup@brainfault.org, ink@jurassic.park.msu.ru, johannes@sipsolutions.net, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Thu, Jun 09, 2022 at 04:49:21PM -0700, Jacob Pan wrote: > Hi Peter, > > On Wed, 08 Jun 2022 16:27:27 +0200, Peter Zijlstra > wrote: > > > Commit c227233ad64c ("intel_idle: enable interrupts before C1 on > > Xeons") wrecked intel_idle in two ways: > > > > - must not have tracing in idle functions > > - must return with IRQs disabled > > > > Additionally, it added a branch for no good reason. > > > > Fixes: c227233ad64c ("intel_idle: enable interrupts before C1 on Xeons") > > Signed-off-by: Peter Zijlstra (Intel) > > --- > > drivers/idle/intel_idle.c | 48 > > +++++++++++++++++++++++++++++++++++----------- 1 file changed, 37 > > insertions(+), 11 deletions(-) > > > > --- a/drivers/idle/intel_idle.c > > +++ b/drivers/idle/intel_idle.c > > @@ -129,21 +137,37 @@ static unsigned int mwait_substates __in > > * > > * Must be called under local_irq_disable(). > > */ > nit: this comment is no long true, right? It still is, all the idle routines are called with interrupts disabled, but must also exit with interrupts disabled. If the idle method requires interrupts to be enabled, it must be sure to disable them again before returning. Given all the RCU/tracing concerns it must use raw_local_irq_*() for this though. 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Received: from dhcp-077-249-017-003.chello.nl ([77.249.17.3] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1o0fgN-007Vf8-Ah; Mon, 13 Jun 2022 08:44:23 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id D73DB302D9E; Mon, 13 Jun 2022 10:44:22 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id BB85B200C72F2; Mon, 13 Jun 2022 10:44:22 +0200 (CEST) Date: Mon, 13 Jun 2022 10:44:22 +0200 From: Peter Zijlstra To: Jacob Pan Cc: rth@twiddle.net, ink@jurassic.park.msu.ru, mattst88@gmail.com, vgupta@kernel.org, linux@armlinux.org.uk, ulli.kroll@googlemail.com, linus.walleij@linaro.org, shawnguo@kernel.org, Sascha Hauer , kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, tony@atomide.com, khilman@kernel.org, catalin.marinas@arm.com, will@kernel.org, guoren@kernel.org, bcain@quicinc.com, chenhuacai@kernel.org, kernel@xen0n.name, geert@linux-m68k.org, sammy@sammy.net, monstr@monstr.eu, tsbogend@alpha.franken.de, dinguyen@kernel.org, jonas@southpole.se, stefan.kristiansson@saunalahti.fi, shorne@gmail.com, James.Bottomley@hansenpartnership.com, deller@gmx.de, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, ysato@users.sourceforge.jp, dalias@libc.org, davem@davemloft.net, richard@nod.at, anton.ivanov@cambridgegreys.com, johannes@sipsolutions.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, namhyung@kernel.org, jgross@suse.com, srivatsa@csail.mit.edu, amakhalov@vmware.com, pv-drivers@vmware.com, boris.ostrovsky@oracle.com, chris@zankel.net, jcmvbkbc@gmail.com, rafael@kernel.org, lenb@kernel.org, pavel@ucw.cz, gregkh@linuxfoundation.org, mturquette@baylibre.com, sboyd@kernel.org, daniel.lezcano@linaro.org, lpieralisi@kernel.org, sudeep.holla@arm.com, agross@kernel.org, bjorn.andersson@linaro.org, anup@brainfault.org, thierry.reding@gmail.com, jonathanh@nvidia.com, Arnd Bergmann , yury.norov@gmail.com, andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk, rostedt@goodmis.org, pmladek@suse.com, senozhatsky@chromium.org, john.ogness@linutronix.de, paulmck@kernel.org, frederic@kernel.org, quic_neeraju@quicinc.com, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, joel@joelfernandes.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, jpoimboe@kernel.org, linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-perf-users@vger.kernel.org, virtualization@lists.linux-foundation.org, xen-devel@lists.xenproject.org, linux-xtensa@linux-xtensa.org, linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, linux-clk@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-tegra@vger.kernel.org, linux-arch@vger.kernel.org, rcu@vger.kernel.org Subject: Re: [PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE Message-ID: References: <20220608142723.103523089@infradead.org> <20220608144516.172460444@infradead.org> <20220609164921.5e61711d@jacob-builder> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220609164921.5e61711d@jacob-builder> X-Mailman-Approved-At: Mon, 13 Jun 2022 17:18:13 -0700 X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Thu, Jun 09, 2022 at 04:49:21PM -0700, Jacob Pan wrote: > Hi Peter, > > On Wed, 08 Jun 2022 16:27:27 +0200, Peter Zijlstra > wrote: > > > Commit c227233ad64c ("intel_idle: enable interrupts before C1 on > > Xeons") wrecked intel_idle in two ways: > > > > - must not have tracing in idle functions > > - must return with IRQs disabled > > > > Additionally, it added a branch for no good reason. > > > > Fixes: c227233ad64c ("intel_idle: enable interrupts before C1 on Xeons") > > Signed-off-by: Peter Zijlstra (Intel) > > --- > > drivers/idle/intel_idle.c | 48 > > +++++++++++++++++++++++++++++++++++----------- 1 file changed, 37 > > insertions(+), 11 deletions(-) > > > > --- a/drivers/idle/intel_idle.c > > +++ b/drivers/idle/intel_idle.c > > @@ -129,21 +137,37 @@ static unsigned int mwait_substates __in > > * > > * Must be called under local_irq_disable(). > > */ > nit: this comment is no long true, right? It still is, all the idle routines are called with interrupts disabled, but must also exit with interrupts disabled. If the idle method requires interrupts to be enabled, it must be sure to disable them again before returning. Given all the RCU/tracing concerns it must use raw_local_irq_*() for this though. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.librecores.org (lists.librecores.org [88.198.125.70]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8C39CCA47D for ; Tue, 14 Jun 2022 00:48:16 +0000 (UTC) Received: from [172.31.1.100] (localhost.localdomain [127.0.0.1]) by mail.librecores.org (Postfix) with ESMTP id B05C8248FF; Tue, 14 Jun 2022 02:48:14 +0200 (CEST) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) by mail.librecores.org (Postfix) with ESMTPS id 928E023F5F for ; Mon, 13 Jun 2022 10:45:02 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; 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Mon, 13 Jun 2022 10:44:22 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id BB85B200C72F2; Mon, 13 Jun 2022 10:44:22 +0200 (CEST) Date: Mon, 13 Jun 2022 10:44:22 +0200 From: Peter Zijlstra To: Jacob Pan Subject: Re: [PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE Message-ID: References: <20220608142723.103523089@infradead.org> <20220608144516.172460444@infradead.org> <20220609164921.5e61711d@jacob-builder> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220609164921.5e61711d@jacob-builder> X-Mailman-Approved-At: Tue, 14 Jun 2022 02:48:12 +0200 X-BeenThere: openrisc@lists.librecores.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: Discussion around the OpenRISC processor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: juri.lelli@redhat.com, rafael@kernel.org, benh@kernel.crashing.org, linus.walleij@linaro.org, bsegall@google.com, guoren@kernel.org, pavel@ucw.cz, agordeev@linux.ibm.com, srivatsa@csail.mit.edu, linux-arch@vger.kernel.org, vincent.guittot@linaro.org, mpe@ellerman.id.au, chenhuacai@kernel.org, linux-acpi@vger.kernel.org, agross@kernel.org, linux-imx@nxp.com, catalin.marinas@arm.com, xen-devel@lists.xenproject.org, mattst88@gmail.com, borntraeger@linux.ibm.com, mturquette@baylibre.com, sammy@sammy.net, pmladek@suse.com, linux-pm@vger.kernel.org, jiangshanlai@gmail.com, Sascha Hauer , linux-um@lists.infradead.org, acme@kernel.org, tglx@linutronix.de, linux-omap@vger.kernel.org, dietmar.eggemann@arm.com, rth@twiddle.net, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, senozhatsky@chromium.org, svens@linux.ibm.com, jolsa@kernel.org, paulus@samba.org, mark.rutland@arm.com, linux-ia64@vger.kernel.org, dave.hansen@linux.intel.com, virtualization@lists.linux-foundation.org, James.Bottomley@hansenpartnership.com, jcmvbkbc@gmail.com, thierry.reding@gmail.com, kernel@xen0n.name, quic_neeraju@quicinc.com, linux-s390@vger.kernel.org, vschneid@redhat.com, john.ogness@linutronix.de, ysato@users.sourceforge.jp, linux-sh@vger.kernel.org, festevam@gmail.com, deller@gmx.de, daniel.lezcano@linaro.org, jonathanh@nvidia.com, mathieu.desnoyers@efficios.com, frederic@kernel.org, lenb@kernel.org, linux-xtensa@linux-xtensa.org, kernel@pengutronix.de, gor@linux.ibm.com, linux-arm-msm@vger.kernel.org, linux-alpha@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-arm-kernel@lists.infradead.org, chris@zankel.net, sboyd@kernel.org, dinguyen@kernel.org, bristot@redhat.com, alexander.shishkin@linux.intel.com, lpieralisi@kernel.org, linux@rasmusvillemoes.dk, joel@joelfernandes.org, will@kernel.org, boris.ostrovsky@oracle.com, khilman@kernel.org, linux-csky@vger.kernel.org, pv-drivers@vmware.com, linux-snps-arc@lists.infradead.org, mgorman@suse.de, Arnd Bergmann , ulli.kroll@googlemail.com, vgupta@kernel.org, linux-clk@vger.kernel.org, josh@joshtriplett.org, rostedt@goodmis.org, rcu@vger.kernel.org, bp@alien8.de, bcain@quicinc.com, tsbogend@alpha.franken.de, linux-parisc@vger.kernel.org, sudeep.holla@arm.com, shawnguo@kernel.org, davem@davemloft.net, dalias@libc.org, tony@atomide.com, amakhalov@vmware.com, bjorn.andersson@linaro.org, hpa@zytor.com, sparclinux@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-riscv@lists.infradead.org, anton.ivanov@cambridgegreys.com, jonas@southpole.se, yury.norov@gmail.com, richard@nod.at, x86@kernel.org, linux@armlinux.org.uk, mingo@redhat.com, aou@eecs.berkeley.edu, paulmck@kernel.org, hca@linux.ibm.com, openrisc@lists.librecores.org, paul.walmsley@sifive.com, linux-tegra@vger.kernel.org, namhyung@kernel.org, andriy.shevchenko@linux.intel.com, jpoimboe@kernel.org, jgross@suse.com, monstr@monstr.eu, linux-mips@vger.kernel.org, palmer@dabbelt.com, anup@brainfault.org, ink@jurassic.park.msu.ru, johannes@sipsolutions.net, linuxppc-dev@lists.ozlabs.org Errors-To: openrisc-bounces@lists.librecores.org Sender: "OpenRISC" On Thu, Jun 09, 2022 at 04:49:21PM -0700, Jacob Pan wrote: > Hi Peter, > > On Wed, 08 Jun 2022 16:27:27 +0200, Peter Zijlstra > wrote: > > > Commit c227233ad64c ("intel_idle: enable interrupts before C1 on > > Xeons") wrecked intel_idle in two ways: > > > > - must not have tracing in idle functions > > - must return with IRQs disabled > > > > Additionally, it added a branch for no good reason. > > > > Fixes: c227233ad64c ("intel_idle: enable interrupts before C1 on Xeons") > > Signed-off-by: Peter Zijlstra (Intel) > > --- > > drivers/idle/intel_idle.c | 48 > > +++++++++++++++++++++++++++++++++++----------- 1 file changed, 37 > > insertions(+), 11 deletions(-) > > > > --- a/drivers/idle/intel_idle.c > > +++ b/drivers/idle/intel_idle.c > > @@ -129,21 +137,37 @@ static unsigned int mwait_substates __in > > * > > * Must be called under local_irq_disable(). > > */ > nit: this comment is no long true, right? It still is, all the idle routines are called with interrupts disabled, but must also exit with interrupts disabled. If the idle method requires interrupts to be enabled, it must be sure to disable them again before returning. Given all the RCU/tracing concerns it must use raw_local_irq_*() for this though. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Date: Mon, 13 Jun 2022 08:44:22 +0000 Subject: Re: [PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE Message-Id: List-Id: References: <20220608142723.103523089@infradead.org> <20220608144516.172460444@infradead.org> <20220609164921.5e61711d@jacob-builder> In-Reply-To: <20220609164921.5e61711d@jacob-builder> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jacob Pan Cc: rth@twiddle.net, ink@jurassic.park.msu.ru, mattst88@gmail.com, vgupta@kernel.org, linux@armlinux.org.uk, ulli.kroll@googlemail.com, linus.walleij@linaro.org, shawnguo@kernel.org, Sascha Hauer , kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, tony@atomide.com, khilman@kernel.org, catalin.marinas@arm.com, will@kernel.org, guoren@kernel.org, bcain@quicinc.com, chenhuacai@kernel.org, kernel@xen0n.name, geert@linux-m68k.org, sammy@sammy.net, monstr@monstr.eu, tsbogend@alpha.franken.de, dinguyen@kernel.org, jonas@southpole.se, stefan.kristiansson@saunalahti.fi, shorne@gmail.com, James.Bottomley@hansenpartnership.com, deller@gmx.de, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, ysato@users.sourceforge.jp, dalias@libc.org, davem@davemloft.net, richard@nod.at, anton.ivanov@cambridgegreys.com, johannes@sipsolutions.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, namhyung@kernel.org, jgross@suse.com, srivatsa@csail.mit.edu, amakhalov@vmware.com, pv-drivers@vmware.com, boris.ostrovsky@oracle.com, chris@zankel.net, jcmvbkbc@gmail.com, rafael@kernel.org, lenb@kernel.org, pavel@ucw.cz, gregkh@linuxfoundation.org, mturquette@baylibre.com, sboyd@kernel.org, daniel.lezcano@linaro.org, lpieralisi@kernel.org, sudeep.holla@arm.com, agross@kernel.org, bjorn.andersson@linaro.org, anup@brainfault.org, thierry.reding@gmail.com, jonathanh@nvidia.com, Arnd Bergmann , yury.norov@gmail.com, andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk, rostedt@goodmis.org, pmladek@suse.com, senozhatsky@chromium.org, john.ogness@linutronix.de, paulmck@kernel.org, frederic@kernel.org, quic_neeraju@quicinc.com, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, joel@joelfernandes.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, jpoimboe@kernel.org, linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-perf-users@vger.kernel.org, virtualization@lists.linux-foundation.org, xen-devel@lists.xenproject.org, linux-xtensa@linux-xtensa.org, linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, linux-clk@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-tegra@vger.kernel.org, linux-arch@vger.kernel.org, rcu@vger.kernel.org On Thu, Jun 09, 2022 at 04:49:21PM -0700, Jacob Pan wrote: > Hi Peter, > > On Wed, 08 Jun 2022 16:27:27 +0200, Peter Zijlstra > wrote: > > > Commit c227233ad64c ("intel_idle: enable interrupts before C1 on > > Xeons") wrecked intel_idle in two ways: > > > > - must not have tracing in idle functions > > - must return with IRQs disabled > > > > Additionally, it added a branch for no good reason. > > > > Fixes: c227233ad64c ("intel_idle: enable interrupts before C1 on Xeons") > > Signed-off-by: Peter Zijlstra (Intel) > > --- > > drivers/idle/intel_idle.c | 48 > > +++++++++++++++++++++++++++++++++++----------- 1 file changed, 37 > > insertions(+), 11 deletions(-) > > > > --- a/drivers/idle/intel_idle.c > > +++ b/drivers/idle/intel_idle.c > > @@ -129,21 +137,37 @@ static unsigned int mwait_substates __in > > * > > * Must be called under local_irq_disable(). > > */ > nit: this comment is no long true, right? It still is, all the idle routines are called with interrupts disabled, but must also exit with interrupts disabled. If the idle method requires interrupts to be enabled, it must be sure to disable them again before returning. Given all the RCU/tracing concerns it must use raw_local_irq_*() for this though. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [PATCH 04/36] cpuidle,intel_idle: Fix CPUIDLE_FLAG_IRQ_ENABLE Date: Mon, 13 Jun 2022 10:44:22 +0200 Message-ID: References: <20220608142723.103523089@infradead.org> <20220608144516.172460444@infradead.org> <20220609164921.5e61711d@jacob-builder> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=pN3d4KEFcv2ptnSv0mvCj6MvUML0g63O/kngZ8T7P5U=; b=jHY41velXm5OfTDUZVWOgGoGBS 3XcfJnIs2Kw4MnQzhXHXXp0NuTvYgWNNcy9H8ZMc64VSaMQLttlBqVnSkycnBSdvSyy0Jak2Oc/oh vvGayo0C9yY99bqhrLdUZmtWJXcMrqnljzCxzdeOwv7I5/kT19cRmZ3SrWtebHTgXMFdZAZxKh/LD FLvZqYIpmAvjq1lnM+gSi7696QvqdD2nf0hqYc6h4USx92PA9LVEoUSL3WQM5ig7zhrj1+/gECYeb R1xWNHwwSLm1F21Q9Cu7wJn7J1PofxmN5bqxHgiOokEGCrOE72TMA7ta7eHf7Pxf1c+Q+Jc6wUzzF Why4PJmw==; Content-Disposition: inline In-Reply-To: <20220609164921.5e61711d@jacob-builder> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" To: Jacob Pan Cc: juri.lelli@redhat.com, rafael@kernel.org, benh@kernel.crashing.org, linus.walleij@linaro.org, bsegall@google.com, guoren@kernel.org, pavel@ucw.cz, agordeev@linux.ibm.com, linux-arch@vger.kernel.org, vincent.guittot@linaro.org, mpe@ellerman.id.au, chenhuacai@kernel.org, linux-acpi@vger.kernel.org, agross@kernel.org, geert@linux-m68k.org, linux-imx@nxp.com, catalin.marinas@arm.com, xen-devel@lists.xenproject.org, mattst88@gmail.com, mturquette@baylibre.com, sammy@sammy.net, pmladek@suse.com, linux-pm@vger.kernel.org, jiangshanlai@gmail.com, Sascha Hauer , linux-um@lists.infradead.org, acme@kernel.org, tglx@linutronix.de, linux-omap@vger.kernel.org, dietmar.eggemann@arm.com, rth@twiddle.net, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, senozhatsky@chromium.org, svens@linux.ibm.com, jolsa@kernel.org, paul On Thu, Jun 09, 2022 at 04:49:21PM -0700, Jacob Pan wrote: > Hi Peter, > > On Wed, 08 Jun 2022 16:27:27 +0200, Peter Zijlstra > wrote: > > > Commit c227233ad64c ("intel_idle: enable interrupts before C1 on > > Xeons") wrecked intel_idle in two ways: > > > > - must not have tracing in idle functions > > - must return with IRQs disabled > > > > Additionally, it added a branch for no good reason. > > > > Fixes: c227233ad64c ("intel_idle: enable interrupts before C1 on Xeons") > > Signed-off-by: Peter Zijlstra (Intel) > > --- > > drivers/idle/intel_idle.c | 48 > > +++++++++++++++++++++++++++++++++++----------- 1 file changed, 37 > > insertions(+), 11 deletions(-) > > > > --- a/drivers/idle/intel_idle.c > > +++ b/drivers/idle/intel_idle.c > > @@ -129,21 +137,37 @@ static unsigned int mwait_substates __in > > * > > * Must be called under local_irq_disable(). > > */ > nit: this comment is no long true, right? It still is, all the idle routines are called with interrupts disabled, but must also exit with interrupts disabled. If the idle method requires interrupts to be enabled, it must be sure to disable them again before returning. Given all the RCU/tracing concerns it must use raw_local_irq_*() for this though.