From: Douglas Anderson <dianders@chromium.org> To: Mark Rutland <mark.rutland@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Sumit Garg <sumit.garg@linaro.org>, Daniel Thompson <daniel.thompson@linaro.org>, Marc Zyngier <maz@kernel.org> Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>, linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>, kgdb-bugreport@lists.sourceforge.net, ito-yuichi@fujitsu.com, Stephen Boyd <swboyd@chromium.org>, Thomas Gleixner <tglx@linutronix.de>, Chen-Yu Tsai <wens@csie.org>, Ard Biesheuvel <ardb@kernel.org>, "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>, Masayoshi Mizuma <msys.mizuma@gmail.com>, Douglas Anderson <dianders@chromium.org>, Frederic Weisbecker <frederic@kernel.org>, Guo Ren <guoren@kernel.org>, linux-kernel@vger.kernel.org Subject: [PATCH v10 2/6] arm64: idle: Tag the arm64 idle functions as __cpuidle Date: Tue, 22 Aug 2023 14:26:57 -0700 [thread overview] Message-ID: <20230822142644.v10.2.I4baba13e220bdd24d11400c67f137c35f07f82c7@changeid> (raw) In-Reply-To: <20230822212927.249645-1-dianders@chromium.org> As per the (somewhat recent) comment before the definition of `__cpuidle`, the tag is like `noinstr` but also marks a function so it can be identified by cpu_in_idle(). Let'a add this. After doing this then when we dump stack traces of all processors using nmi_cpu_backtrace() then instead of getting useless backtraces we get things like: NMI backtrace for cpu N skipped: idling at cpu_do_idle+0x94/0x98 NOTE: this patch won't make cpu_in_idle() work perfectly for arm64, but it doesn't hurt and does catch some cases. Specifically an example that wasn't caught in my testing looked like this: gic_cpu_sys_reg_init+0x1f8/0x314 gic_cpu_pm_notifier+0x40/0x78 raw_notifier_call_chain+0x5c/0x134 cpu_pm_notify+0x38/0x64 cpu_pm_exit+0x20/0x2c psci_enter_idle_state+0x48/0x70 cpuidle_enter_state+0xb8/0x260 cpuidle_enter+0x44/0x5c do_idle+0x188/0x30c Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Douglas Anderson <dianders@chromium.org> --- (no changes since v9) Changes in v9: - Added to commit message that this doesn't catch all cases. Changes in v8: - "Tag the arm64 idle functions as __cpuidle" new for v8 arch/arm64/kernel/idle.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/idle.c b/arch/arm64/kernel/idle.c index c1125753fe9b..05cfb347ec26 100644 --- a/arch/arm64/kernel/idle.c +++ b/arch/arm64/kernel/idle.c @@ -20,7 +20,7 @@ * ensure that interrupts are not masked at the PMR (because the core will * not wake up if we block the wake up signal in the interrupt controller). */ -void noinstr cpu_do_idle(void) +void __cpuidle cpu_do_idle(void) { struct arm_cpuidle_irq_context context; @@ -35,7 +35,7 @@ void noinstr cpu_do_idle(void) /* * This is our default idle handler. */ -void noinstr arch_cpu_idle(void) +void __cpuidle arch_cpu_idle(void) { /* * This should do all the clock switching and wait for interrupt -- 2.42.0.rc1.204.g551eb34607-goog
WARNING: multiple messages have this Message-ID (diff)
From: Douglas Anderson <dianders@chromium.org> To: Mark Rutland <mark.rutland@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Sumit Garg <sumit.garg@linaro.org>, Daniel Thompson <daniel.thompson@linaro.org>, Marc Zyngier <maz@kernel.org> Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>, linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>, kgdb-bugreport@lists.sourceforge.net, ito-yuichi@fujitsu.com, Stephen Boyd <swboyd@chromium.org>, Thomas Gleixner <tglx@linutronix.de>, Chen-Yu Tsai <wens@csie.org>, Ard Biesheuvel <ardb@kernel.org>, "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>, Masayoshi Mizuma <msys.mizuma@gmail.com>, Douglas Anderson <dianders@chromium.org>, Frederic Weisbecker <frederic@kernel.org>, Guo Ren <guoren@kernel.org>, linux-kernel@vger.kernel.org Subject: [PATCH v10 2/6] arm64: idle: Tag the arm64 idle functions as __cpuidle Date: Tue, 22 Aug 2023 14:26:57 -0700 [thread overview] Message-ID: <20230822142644.v10.2.I4baba13e220bdd24d11400c67f137c35f07f82c7@changeid> (raw) In-Reply-To: <20230822212927.249645-1-dianders@chromium.org> As per the (somewhat recent) comment before the definition of `__cpuidle`, the tag is like `noinstr` but also marks a function so it can be identified by cpu_in_idle(). Let'a add this. After doing this then when we dump stack traces of all processors using nmi_cpu_backtrace() then instead of getting useless backtraces we get things like: NMI backtrace for cpu N skipped: idling at cpu_do_idle+0x94/0x98 NOTE: this patch won't make cpu_in_idle() work perfectly for arm64, but it doesn't hurt and does catch some cases. Specifically an example that wasn't caught in my testing looked like this: gic_cpu_sys_reg_init+0x1f8/0x314 gic_cpu_pm_notifier+0x40/0x78 raw_notifier_call_chain+0x5c/0x134 cpu_pm_notify+0x38/0x64 cpu_pm_exit+0x20/0x2c psci_enter_idle_state+0x48/0x70 cpuidle_enter_state+0xb8/0x260 cpuidle_enter+0x44/0x5c do_idle+0x188/0x30c Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Douglas Anderson <dianders@chromium.org> --- (no changes since v9) Changes in v9: - Added to commit message that this doesn't catch all cases. Changes in v8: - "Tag the arm64 idle functions as __cpuidle" new for v8 arch/arm64/kernel/idle.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/idle.c b/arch/arm64/kernel/idle.c index c1125753fe9b..05cfb347ec26 100644 --- a/arch/arm64/kernel/idle.c +++ b/arch/arm64/kernel/idle.c @@ -20,7 +20,7 @@ * ensure that interrupts are not masked at the PMR (because the core will * not wake up if we block the wake up signal in the interrupt controller). */ -void noinstr cpu_do_idle(void) +void __cpuidle cpu_do_idle(void) { struct arm_cpuidle_irq_context context; @@ -35,7 +35,7 @@ void noinstr cpu_do_idle(void) /* * This is our default idle handler. */ -void noinstr arch_cpu_idle(void) +void __cpuidle arch_cpu_idle(void) { /* * This should do all the clock switching and wait for interrupt -- 2.42.0.rc1.204.g551eb34607-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2023-08-22 21:30 UTC|newest] Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-08-22 21:26 [PATCH v10 0/6] arm64: Add IPI for backtraces / kgdb; try to use NMI for some IPIs Douglas Anderson 2023-08-22 21:26 ` Douglas Anderson 2023-08-22 21:26 ` [PATCH v10 1/6] irqchip/gic-v3: Enable support for SGIs to act as NMIs Douglas Anderson 2023-08-22 21:26 ` Douglas Anderson 2023-08-22 21:26 ` Douglas Anderson [this message] 2023-08-22 21:26 ` [PATCH v10 2/6] arm64: idle: Tag the arm64 idle functions as __cpuidle Douglas Anderson 2023-08-22 23:14 ` Stephen Boyd 2023-08-22 23:14 ` Stephen Boyd 2023-08-22 21:26 ` [PATCH v10 3/6] arm64: smp: Remove dedicated wakeup IPI Douglas Anderson 2023-08-22 21:26 ` Douglas Anderson 2023-08-22 23:16 ` Stephen Boyd 2023-08-22 23:16 ` Stephen Boyd 2023-08-22 21:26 ` [PATCH v10 4/6] arm64: smp: Add arch support for backtrace using pseudo-NMI Douglas Anderson 2023-08-22 21:26 ` Douglas Anderson 2023-08-22 23:39 ` Stephen Boyd 2023-08-22 23:39 ` Stephen Boyd 2023-08-23 19:58 ` kernel test robot 2023-08-23 19:58 ` kernel test robot 2023-08-22 21:27 ` [PATCH v10 5/6] arm64: smp: IPI_CPU_STOP and IPI_CPU_CRASH_STOP should try for NMI Douglas Anderson 2023-08-22 21:27 ` Douglas Anderson 2023-08-22 23:41 ` Stephen Boyd 2023-08-22 23:41 ` Stephen Boyd 2023-08-22 21:27 ` [PATCH v10 6/6] arm64: kgdb: Implement kgdb_roundup_cpus() to enable pseudo-NMI roundup Douglas Anderson 2023-08-22 21:27 ` Douglas Anderson 2023-08-22 23:50 ` Stephen Boyd 2023-08-22 23:50 ` Stephen Boyd
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