From: Doug 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: linux-arm-kernel@lists.infradead.org,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Lecopzer Chen <lecopzer.chen@mediatek.com>,
Chen-Yu Tsai <wens@csie.org>,
Tomohiro Misono <misono.tomohiro@fujitsu.com>,
Peter Zijlstra <peterz@infradead.org>,
Masayoshi Mizuma <msys.mizuma@gmail.com>,
Stephane Eranian <eranian@google.com>,
Ard Biesheuvel <ardb@kernel.org>,
kgdb-bugreport@lists.sourceforge.net,
Stephen Boyd <swboyd@chromium.org>,
linux-perf-users@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
ito-yuichi@fujitsu.com, Chen-Yu Tsai <wenst@chromium.org>,
jpoimboe@kernel.org, keescook@chromium.org,
linux-kernel@vger.kernel.org, philmd@linaro.org,
samitolvanen@google.com, scott@os.amperecomputing.com,
vschneid@redhat.com
Subject: Re: [PATCH v13 3/7] arm64: smp: Remove dedicated wakeup IPI
Date: Mon, 2 Oct 2023 09:48:08 -0700 [thread overview]
Message-ID: <CAD=FV=WCcwc71hSMQVQN4AYi7XhKpOwbOZnt8b9iGUgqmvzuKw@mail.gmail.com> (raw)
In-Reply-To: <CAD=FV=UBw1-9=LPUydewyOg8oL2WMG+ZCQ=PBpe0CiCs-ToWSg@mail.gmail.com>
Hi,
On Mon, Sep 25, 2023 at 5:39 PM Doug Anderson <dianders@chromium.org> wrote:
>
> Mark,
>
> On Wed, Sep 6, 2023 at 9:06 AM Douglas Anderson <dianders@chromium.org> wrote:
> >
> > +#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
> > +void arch_send_wakeup_ipi(unsigned int cpu)
> > +{
> > + /*
> > + * We use a scheduler IPI to wake the CPU as this avoids the need for a
> > + * dedicated IPI and we can safely handle spurious scheduler IPIs.
> > + */
> > + arch_smp_send_reschedule(cpu);
>
> I was backporting this to our ChromeOS kernels and our build test bot
> noticed that arch_smp_send_reschedule() didn't exist in older kernels.
> That's fine--I can always adjust this patch when backporting or
> cherry-pick extra patches, but it made me wonder. Is there a reason
> you chose to use arch_smp_send_reschedule() directly here instead of
> smp_send_reschedule()? I guess the only difference is that you're
> bypassing the tracing. Is that on purpose? Should we add a comment
> about it, or change this to smp_send_reschedule()?
FWIW, I posted a patch changing this to smp_send_reschedule(). Please
yell if this is incorrect.
https://lore.kernel.org/r/20231002094526.2.I2e6d22fc42ccbf6b26465a28a10e36e05ccf3075@changeid
WARNING: multiple messages have this Message-ID (diff)
From: Doug 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: linux-arm-kernel@lists.infradead.org,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Lecopzer Chen <lecopzer.chen@mediatek.com>,
Chen-Yu Tsai <wens@csie.org>,
Tomohiro Misono <misono.tomohiro@fujitsu.com>,
Peter Zijlstra <peterz@infradead.org>,
Masayoshi Mizuma <msys.mizuma@gmail.com>,
Stephane Eranian <eranian@google.com>,
Ard Biesheuvel <ardb@kernel.org>,
kgdb-bugreport@lists.sourceforge.net,
Stephen Boyd <swboyd@chromium.org>,
linux-perf-users@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
ito-yuichi@fujitsu.com, Chen-Yu Tsai <wenst@chromium.org>,
jpoimboe@kernel.org, keescook@chromium.org,
linux-kernel@vger.kernel.org, philmd@linaro.org,
samitolvanen@google.com, scott@os.amperecomputing.com,
vschneid@redhat.com
Subject: Re: [PATCH v13 3/7] arm64: smp: Remove dedicated wakeup IPI
Date: Mon, 2 Oct 2023 09:48:08 -0700 [thread overview]
Message-ID: <CAD=FV=WCcwc71hSMQVQN4AYi7XhKpOwbOZnt8b9iGUgqmvzuKw@mail.gmail.com> (raw)
In-Reply-To: <CAD=FV=UBw1-9=LPUydewyOg8oL2WMG+ZCQ=PBpe0CiCs-ToWSg@mail.gmail.com>
Hi,
On Mon, Sep 25, 2023 at 5:39 PM Doug Anderson <dianders@chromium.org> wrote:
>
> Mark,
>
> On Wed, Sep 6, 2023 at 9:06 AM Douglas Anderson <dianders@chromium.org> wrote:
> >
> > +#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
> > +void arch_send_wakeup_ipi(unsigned int cpu)
> > +{
> > + /*
> > + * We use a scheduler IPI to wake the CPU as this avoids the need for a
> > + * dedicated IPI and we can safely handle spurious scheduler IPIs.
> > + */
> > + arch_smp_send_reschedule(cpu);
>
> I was backporting this to our ChromeOS kernels and our build test bot
> noticed that arch_smp_send_reschedule() didn't exist in older kernels.
> That's fine--I can always adjust this patch when backporting or
> cherry-pick extra patches, but it made me wonder. Is there a reason
> you chose to use arch_smp_send_reschedule() directly here instead of
> smp_send_reschedule()? I guess the only difference is that you're
> bypassing the tracing. Is that on purpose? Should we add a comment
> about it, or change this to smp_send_reschedule()?
FWIW, I posted a patch changing this to smp_send_reschedule(). Please
yell if this is incorrect.
https://lore.kernel.org/r/20231002094526.2.I2e6d22fc42ccbf6b26465a28a10e36e05ccf3075@changeid
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next prev parent reply other threads:[~2023-10-02 16:48 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-06 16:02 [PATCH v13 0/7] arm64: Add IPI for backtraces / kgdb; try to use NMI for some IPIs Douglas Anderson
2023-09-06 16:02 ` Douglas Anderson
2023-09-06 16:02 ` [PATCH v13 1/7] irqchip/gic-v3: Enable support for SGIs to act as NMIs Douglas Anderson
2023-09-06 16:02 ` Douglas Anderson
2023-09-12 12:43 ` Marc Zyngier
2023-09-12 12:43 ` Marc Zyngier
2023-09-06 16:02 ` [PATCH v13 2/7] arm64: idle: Tag the arm64 idle functions as __cpuidle Douglas Anderson
2023-09-06 16:02 ` Douglas Anderson
2023-09-06 16:02 ` [PATCH v13 3/7] arm64: smp: Remove dedicated wakeup IPI Douglas Anderson
2023-09-06 16:02 ` Douglas Anderson
2023-09-26 0:39 ` Doug Anderson
2023-09-26 0:39 ` Doug Anderson
2023-10-02 16:48 ` Doug Anderson [this message]
2023-10-02 16:48 ` Doug Anderson
2023-09-06 16:02 ` [PATCH v13 4/7] arm64: smp: Add arch support for backtrace using pseudo-NMI Douglas Anderson
2023-09-06 16:02 ` Douglas Anderson
2023-09-06 16:03 ` [PATCH v13 5/7] arm64: smp: IPI_CPU_STOP and IPI_CPU_CRASH_STOP should try for NMI Douglas Anderson
2023-09-06 16:03 ` Douglas Anderson
2023-09-06 16:03 ` [PATCH v13 6/7] arm64: kgdb: Implement kgdb_roundup_cpus() to enable pseudo-NMI roundup Douglas Anderson
2023-09-06 16:03 ` Douglas Anderson
2023-09-06 16:03 ` [PATCH v13 7/7] arm64: smp: Mark IPI globals as __ro_after_init Douglas Anderson
2023-09-06 16:03 ` Douglas Anderson
2023-09-06 21:45 ` Stephen Boyd
2023-09-06 21:45 ` Stephen Boyd
2023-09-25 17:10 ` [PATCH v13 0/7] arm64: Add IPI for backtraces / kgdb; try to use NMI for some IPIs Catalin Marinas
2023-09-25 17:10 ` Catalin Marinas
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