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Tue, 14 Jun 2022 09:59:50 -0700 (PDT) Date: Tue, 14 Jun 2022 17:59:46 +0100 From: Mark Rutland To: Peter Zijlstra 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, 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, jacob.jun.pan@linux.intel.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 14/36] cpuidle: Fix rcu_idle_*() usage Message-ID: References: <20220608142723.103523089@infradead.org> <20220608144516.808451191@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org On Tue, Jun 14, 2022 at 06:40:53PM +0200, Peter Zijlstra wrote: > On Tue, Jun 14, 2022 at 01:41:13PM +0100, Mark Rutland wrote: > > On Wed, Jun 08, 2022 at 04:27:37PM +0200, Peter Zijlstra wrote: > > > --- a/kernel/time/tick-broadcast.c > > > +++ b/kernel/time/tick-broadcast.c > > > @@ -622,9 +622,13 @@ struct cpumask *tick_get_broadcast_onesh > > > * to avoid a deep idle transition as we are about to get the > > > * broadcast IPI right away. > > > */ > > > -int tick_check_broadcast_expired(void) > > > +noinstr int tick_check_broadcast_expired(void) > > > { > > > +#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H > > > + return arch_test_bit(smp_processor_id(), cpumask_bits(tick_broadcast_force_mask)); > > > +#else > > > return cpumask_test_cpu(smp_processor_id(), tick_broadcast_force_mask); > > > +#endif > > > } > > > > This is somewhat not-ideal. :/ > > I'll say. > > > Could we unconditionally do the arch_test_bit() variant, with a comment, or > > does that not exist in some cases? > > Loads of build errors ensued, which is how I ended up with this mess ... Yaey :( I see the same is true for the thread flag manipulation too. I'll take a look and see if we can layer things so that we can use the arch_*() helpers and wrap those consistently so that we don't have to check the CPP guard. Ideally we'd have a a better language that allows us to make some context-senstive decisions, then we could hide all this gunk in the lower levels with somethin like: if (!THIS_IS_A_NOINSTR_FUNCTION()) { explicit_instrumentation(...); } ... ho hum. Mark. 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Tue, 14 Jun 2022 09:59:50 -0700 (PDT) Date: Tue, 14 Jun 2022 17:59:46 +0100 From: Mark Rutland To: Peter Zijlstra Subject: Re: [PATCH 14/36] cpuidle: Fix rcu_idle_*() usage Message-ID: References: <20220608142723.103523089@infradead.org> <20220608144516.808451191@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: 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, 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, jacob.jun.pan@linux.intel.com, 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 Tue, Jun 14, 2022 at 06:40:53PM +0200, Peter Zijlstra wrote: > On Tue, Jun 14, 2022 at 01:41:13PM +0100, Mark Rutland wrote: > > On Wed, Jun 08, 2022 at 04:27:37PM +0200, Peter Zijlstra wrote: > > > --- a/kernel/time/tick-broadcast.c > > > +++ b/kernel/time/tick-broadcast.c > > > @@ -622,9 +622,13 @@ struct cpumask *tick_get_broadcast_onesh > > > * to avoid a deep idle transition as we are about to get the > > > * broadcast IPI right away. > > > */ > > > -int tick_check_broadcast_expired(void) > > > +noinstr int tick_check_broadcast_expired(void) > > > { > > > +#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H > > > + return arch_test_bit(smp_processor_id(), cpumask_bits(tick_broadcast_force_mask)); > > > +#else > > > return cpumask_test_cpu(smp_processor_id(), tick_broadcast_force_mask); > > > +#endif > > > } > > > > This is somewhat not-ideal. :/ > > I'll say. > > > Could we unconditionally do the arch_test_bit() variant, with a comment, or > > does that not exist in some cases? > > Loads of build errors ensued, which is how I ended up with this mess ... Yaey :( I see the same is true for the thread flag manipulation too. I'll take a look and see if we can layer things so that we can use the arch_*() helpers and wrap those consistently so that we don't have to check the CPP guard. Ideally we'd have a a better language that allows us to make some context-senstive decisions, then we could hide all this gunk in the lower levels with somethin like: if (!THIS_IS_A_NOINSTR_FUNCTION()) { explicit_instrumentation(...); } ... ho hum. Mark. _______________________________________________ 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 5B5F7C43334 for ; Tue, 14 Jun 2022 17:00:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; 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Tue, 14 Jun 2022 09:59:50 -0700 (PDT) Date: Tue, 14 Jun 2022 17:59:46 +0100 From: Mark Rutland To: Peter Zijlstra 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, 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, jacob.jun.pan@linux.intel.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 14/36] cpuidle: Fix rcu_idle_*() usage Message-ID: References: <20220608142723.103523089@infradead.org> <20220608144516.808451191@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220614_100010_558519_F72FAC04 X-CRM114-Status: GOOD ( 17.63 ) 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 Tue, Jun 14, 2022 at 06:40:53PM +0200, Peter Zijlstra wrote: > On Tue, Jun 14, 2022 at 01:41:13PM +0100, Mark Rutland wrote: > > On Wed, Jun 08, 2022 at 04:27:37PM +0200, Peter Zijlstra wrote: > > > --- a/kernel/time/tick-broadcast.c > > > +++ b/kernel/time/tick-broadcast.c > > > @@ -622,9 +622,13 @@ struct cpumask *tick_get_broadcast_onesh > > > * to avoid a deep idle transition as we are about to get the > > > * broadcast IPI right away. > > > */ > > > -int tick_check_broadcast_expired(void) > > > +noinstr int tick_check_broadcast_expired(void) > > > { > > > +#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H > > > + return arch_test_bit(smp_processor_id(), cpumask_bits(tick_broadcast_force_mask)); > > > +#else > > > return cpumask_test_cpu(smp_processor_id(), tick_broadcast_force_mask); > > > +#endif > > > } > > > > This is somewhat not-ideal. :/ > > I'll say. > > > Could we unconditionally do the arch_test_bit() variant, with a comment, or > > does that not exist in some cases? > > Loads of build errors ensued, which is how I ended up with this mess ... Yaey :( I see the same is true for the thread flag manipulation too. I'll take a look and see if we can layer things so that we can use the arch_*() helpers and wrap those consistently so that we don't have to check the CPP guard. Ideally we'd have a a better language that allows us to make some context-senstive decisions, then we could hide all this gunk in the lower levels with somethin like: if (!THIS_IS_A_NOINSTR_FUNCTION()) { explicit_instrumentation(...); } ... ho hum. Mark. _______________________________________________ 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 52AD0C43334 for ; Tue, 14 Jun 2022 17:23:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; 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Tue, 14 Jun 2022 09:59:50 -0700 (PDT) Date: Tue, 14 Jun 2022 17:59:46 +0100 From: Mark Rutland To: Peter Zijlstra 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, 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, jacob.jun.pan@linux.intel.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 14/36] cpuidle: Fix rcu_idle_*() usage Message-ID: References: <20220608142723.103523089@infradead.org> <20220608144516.808451191@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220614_100010_558519_F72FAC04 X-CRM114-Status: GOOD ( 17.63 ) X-Mailman-Approved-At: Tue, 14 Jun 2022 10:23:02 -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 Tue, Jun 14, 2022 at 06:40:53PM +0200, Peter Zijlstra wrote: > On Tue, Jun 14, 2022 at 01:41:13PM +0100, Mark Rutland wrote: > > On Wed, Jun 08, 2022 at 04:27:37PM +0200, Peter Zijlstra wrote: > > > --- a/kernel/time/tick-broadcast.c > > > +++ b/kernel/time/tick-broadcast.c > > > @@ -622,9 +622,13 @@ struct cpumask *tick_get_broadcast_onesh > > > * to avoid a deep idle transition as we are about to get the > > > * broadcast IPI right away. > > > */ > > > -int tick_check_broadcast_expired(void) > > > +noinstr int tick_check_broadcast_expired(void) > > > { > > > +#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H > > > + return arch_test_bit(smp_processor_id(), cpumask_bits(tick_broadcast_force_mask)); > > > +#else > > > return cpumask_test_cpu(smp_processor_id(), tick_broadcast_force_mask); > > > +#endif > > > } > > > > This is somewhat not-ideal. :/ > > I'll say. > > > Could we unconditionally do the arch_test_bit() variant, with a comment, or > > does that not exist in some cases? > > Loads of build errors ensued, which is how I ended up with this mess ... Yaey :( I see the same is true for the thread flag manipulation too. I'll take a look and see if we can layer things so that we can use the arch_*() helpers and wrap those consistently so that we don't have to check the CPP guard. Ideally we'd have a a better language that allows us to make some context-senstive decisions, then we could hide all this gunk in the lower levels with somethin like: if (!THIS_IS_A_NOINSTR_FUNCTION()) { explicit_instrumentation(...); } ... ho hum. Mark. _______________________________________________ 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 AE97FC43334 for ; Tue, 14 Jun 2022 20:02:05 +0000 (UTC) Received: from [172.31.1.100] (localhost.localdomain [127.0.0.1]) by mail.librecores.org (Postfix) with ESMTP id 244BA249B7; Tue, 14 Jun 2022 22:02:05 +0200 (CEST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mail.librecores.org (Postfix) with ESMTP id 8E60524980 for ; Tue, 14 Jun 2022 19:00:08 +0200 (CEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 11469175A; Tue, 14 Jun 2022 10:00:08 -0700 (PDT) Received: from FVFF77S0Q05N (unknown [10.57.41.154]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4A1F03F66F; Tue, 14 Jun 2022 09:59:50 -0700 (PDT) Date: Tue, 14 Jun 2022 17:59:46 +0100 From: Mark Rutland To: Peter Zijlstra Subject: Re: [PATCH 14/36] cpuidle: Fix rcu_idle_*() usage Message-ID: References: <20220608142723.103523089@infradead.org> <20220608144516.808451191@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Mailman-Approved-At: Tue, 14 Jun 2022 22:01:55 +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, 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, jacob.jun.pan@linux.intel.com, 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 Tue, Jun 14, 2022 at 06:40:53PM +0200, Peter Zijlstra wrote: > On Tue, Jun 14, 2022 at 01:41:13PM +0100, Mark Rutland wrote: > > On Wed, Jun 08, 2022 at 04:27:37PM +0200, Peter Zijlstra wrote: > > > --- a/kernel/time/tick-broadcast.c > > > +++ b/kernel/time/tick-broadcast.c > > > @@ -622,9 +622,13 @@ struct cpumask *tick_get_broadcast_onesh > > > * to avoid a deep idle transition as we are about to get the > > > * broadcast IPI right away. > > > */ > > > -int tick_check_broadcast_expired(void) > > > +noinstr int tick_check_broadcast_expired(void) > > > { > > > +#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H > > > + return arch_test_bit(smp_processor_id(), cpumask_bits(tick_broadcast_force_mask)); > > > +#else > > > return cpumask_test_cpu(smp_processor_id(), tick_broadcast_force_mask); > > > +#endif > > > } > > > > This is somewhat not-ideal. :/ > > I'll say. > > > Could we unconditionally do the arch_test_bit() variant, with a comment, or > > does that not exist in some cases? > > Loads of build errors ensued, which is how I ended up with this mess ... Yaey :( I see the same is true for the thread flag manipulation too. I'll take a look and see if we can layer things so that we can use the arch_*() helpers and wrap those consistently so that we don't have to check the CPP guard. Ideally we'd have a a better language that allows us to make some context-senstive decisions, then we could hide all this gunk in the lower levels with somethin like: if (!THIS_IS_A_NOINSTR_FUNCTION()) { explicit_instrumentation(...); } ... ho hum. Mark. 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 95745C433EF for ; Tue, 14 Jun 2022 22:16:13 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4LN2p41QP6z3glb for ; Wed, 15 Jun 2022 08:16:12 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=arm.com (client-ip=217.140.110.172; helo=foss.arm.com; envelope-from=mark.rutland@arm.com; receiver=) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lists.ozlabs.org (Postfix) with ESMTP id 4LMvp03wnxz2xKw for ; Wed, 15 Jun 2022 03:00:39 +1000 (AEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 11469175A; Tue, 14 Jun 2022 10:00:08 -0700 (PDT) Received: from FVFF77S0Q05N (unknown [10.57.41.154]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4A1F03F66F; Tue, 14 Jun 2022 09:59:50 -0700 (PDT) Date: Tue, 14 Jun 2022 17:59:46 +0100 From: Mark Rutland To: Peter Zijlstra Subject: Re: [PATCH 14/36] cpuidle: Fix rcu_idle_*() usage Message-ID: References: <20220608142723.103523089@infradead.org> <20220608144516.808451191@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Mailman-Approved-At: Wed, 15 Jun 2022 08:01:46 +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, linux-ia64@vger.kernel.org, dave.hansen@linux.intel.com, virtualization@lists.linux-foundati on.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 , jacob.jun.pan@linux.intel.com, 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@brainfa ult.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 Tue, Jun 14, 2022 at 06:40:53PM +0200, Peter Zijlstra wrote: > On Tue, Jun 14, 2022 at 01:41:13PM +0100, Mark Rutland wrote: > > On Wed, Jun 08, 2022 at 04:27:37PM +0200, Peter Zijlstra wrote: > > > --- a/kernel/time/tick-broadcast.c > > > +++ b/kernel/time/tick-broadcast.c > > > @@ -622,9 +622,13 @@ struct cpumask *tick_get_broadcast_onesh > > > * to avoid a deep idle transition as we are about to get the > > > * broadcast IPI right away. > > > */ > > > -int tick_check_broadcast_expired(void) > > > +noinstr int tick_check_broadcast_expired(void) > > > { > > > +#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H > > > + return arch_test_bit(smp_processor_id(), cpumask_bits(tick_broadcast_force_mask)); > > > +#else > > > return cpumask_test_cpu(smp_processor_id(), tick_broadcast_force_mask); > > > +#endif > > > } > > > > This is somewhat not-ideal. :/ > > I'll say. > > > Could we unconditionally do the arch_test_bit() variant, with a comment, or > > does that not exist in some cases? > > Loads of build errors ensued, which is how I ended up with this mess ... Yaey :( I see the same is true for the thread flag manipulation too. I'll take a look and see if we can layer things so that we can use the arch_*() helpers and wrap those consistently so that we don't have to check the CPP guard. Ideally we'd have a a better language that allows us to make some context-senstive decisions, then we could hide all this gunk in the lower levels with somethin like: if (!THIS_IS_A_NOINSTR_FUNCTION()) { explicit_instrumentation(...); } ... ho hum. Mark. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Date: Tue, 14 Jun 2022 16:59:46 +0000 Subject: Re: [PATCH 14/36] cpuidle: Fix rcu_idle_*() usage Message-Id: List-Id: References: <20220608142723.103523089@infradead.org> <20220608144516.808451191@infradead.org> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Peter Zijlstra 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, 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, jacob.jun.pan@linux.intel.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 Tue, Jun 14, 2022 at 06:40:53PM +0200, Peter Zijlstra wrote: > On Tue, Jun 14, 2022 at 01:41:13PM +0100, Mark Rutland wrote: > > On Wed, Jun 08, 2022 at 04:27:37PM +0200, Peter Zijlstra wrote: > > > --- a/kernel/time/tick-broadcast.c > > > +++ b/kernel/time/tick-broadcast.c > > > @@ -622,9 +622,13 @@ struct cpumask *tick_get_broadcast_onesh > > > * to avoid a deep idle transition as we are about to get the > > > * broadcast IPI right away. > > > */ > > > -int tick_check_broadcast_expired(void) > > > +noinstr int tick_check_broadcast_expired(void) > > > { > > > +#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H > > > + return arch_test_bit(smp_processor_id(), cpumask_bits(tick_broadcast_force_mask)); > > > +#else > > > return cpumask_test_cpu(smp_processor_id(), tick_broadcast_force_mask); > > > +#endif > > > } > > > > This is somewhat not-ideal. :/ > > I'll say. > > > Could we unconditionally do the arch_test_bit() variant, with a comment, or > > does that not exist in some cases? > > Loads of build errors ensued, which is how I ended up with this mess ... Yaey :( I see the same is true for the thread flag manipulation too. I'll take a look and see if we can layer things so that we can use the arch_*() helpers and wrap those consistently so that we don't have to check the CPP guard. Ideally we'd have a a better language that allows us to make some context-senstive decisions, then we could hide all this gunk in the lower levels with somethin like: if (!THIS_IS_A_NOINSTR_FUNCTION()) { explicit_instrumentation(...); } ... ho hum. Mark. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Subject: Re: [PATCH 14/36] cpuidle: Fix rcu_idle_*() usage Date: Tue, 14 Jun 2022 17:59:46 +0100 Message-ID: References: <20220608142723.103523089@infradead.org> <20220608144516.808451191@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" To: Peter Zijlstra 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 Tue, Jun 14, 2022 at 06:40:53PM +0200, Peter Zijlstra wrote: > On Tue, Jun 14, 2022 at 01:41:13PM +0100, Mark Rutland wrote: > > On Wed, Jun 08, 2022 at 04:27:37PM +0200, Peter Zijlstra wrote: > > > --- a/kernel/time/tick-broadcast.c > > > +++ b/kernel/time/tick-broadcast.c > > > @@ -622,9 +622,13 @@ struct cpumask *tick_get_broadcast_onesh > > > * to avoid a deep idle transition as we are about to get the > > > * broadcast IPI right away. > > > */ > > > -int tick_check_broadcast_expired(void) > > > +noinstr int tick_check_broadcast_expired(void) > > > { > > > +#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H > > > + return arch_test_bit(smp_processor_id(), cpumask_bits(tick_broadcast_force_mask)); > > > +#else > > > return cpumask_test_cpu(smp_processor_id(), tick_broadcast_force_mask); > > > +#endif > > > } > > > > This is somewhat not-ideal. :/ > > I'll say. > > > Could we unconditionally do the arch_test_bit() variant, with a comment, or > > does that not exist in some cases? > > Loads of build errors ensued, which is how I ended up with this mess ... Yaey :( I see the same is true for the thread flag manipulation too. I'll take a look and see if we can layer things so that we can use the arch_*() helpers and wrap those consistently so that we don't have to check the CPP guard. Ideally we'd have a a better language that allows us to make some context-senstive decisions, then we could hide all this gunk in the lower levels with somethin like: if (!THIS_IS_A_NOINSTR_FUNCTION()) { explicit_instrumentation(...); } ... ho hum. Mark.