From: William McVicker <willmcvicker@google.com>
To: John Stultz <jstultz@google.com>
Cc: "Catalin Marinas" <catalin.marinas@arm.com>,
"Will Deacon" <will@kernel.org>,
"Peter Griffin" <peter.griffin@linaro.org>,
"André Draszik" <andre.draszik@linaro.org>,
"Tudor Ambarus" <tudor.ambarus@linaro.org>,
"Rob Herring" <robh@kernel.org>,
"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
"Conor Dooley" <conor+dt@kernel.org>,
"Alim Akhtar" <alim.akhtar@samsung.com>,
"Daniel Lezcano" <daniel.lezcano@linaro.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Saravana Kannan" <saravanak@google.com>,
"Krzysztof Kozlowski" <krzk@kernel.org>,
kernel-team@android.com, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
devicetree@vger.kernel.org,
"Hosung Kim" <hosung0.kim@samsung.com>
Subject: Re: [PATCH v1 3/6] clocksource/drivers/exynos_mct: Set local timer interrupts as percpu
Date: Tue, 1 Apr 2025 09:36:19 -0700 [thread overview]
Message-ID: <Z-wWA-46L08V89qK@google.com> (raw)
In-Reply-To: <CANDhNCqNqXfGgvo8vNof1qi3E3jejk5KBD=oedZp2_p8RKZdjw@mail.gmail.com>
On 03/31/2025, John Stultz wrote:
> On Mon, Mar 31, 2025 at 4:00 PM 'Will McVicker' via kernel-team
> <kernel-team@android.com> wrote:
> >
> > From: Hosung Kim <hosung0.kim@samsung.com>
> >
> > The MCT local timers can be used as a per-cpu event timer. To prevent
>
> Can be used, or are used? If it's an option, is this change important
> in both cases?
>
> > the timer interrupts from migrating to other CPUs, set the flag
> > IRQF_PERCPU.
>
> Might be work expanding this a bit to clarify why the interrupts
> migrating to other cpus is undesired.
Let me dig into this further to figure out if the IP has a limitation where the
interrupts need to be handled by the CPU the timer was triggered on or if this
is just an optimization.
Any chance you know this @Youngmin?
Thanks,
Will
>
> > Signed-off-by: Hosung Kim <hosung0.kim@samsung.com>
> > [Original commit from https://android.googlesource.com/kernel/gs/+/03267fad19f093bac979ca78309483e9eb3a8d16]
> > Signed-off-by: Will McVicker <willmcvicker@google.com>
>
> thanks!
> -john
next prev parent reply other threads:[~2025-04-01 16:36 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-31 23:00 [PATCH v1 0/6] Add module support for Arm64 Exynos MCT driver Will McVicker
2025-03-31 23:00 ` [PATCH v1 1/6] of/irq: Export of_irq_count for modules Will McVicker
2025-04-01 2:30 ` Rob Herring
2025-03-31 23:00 ` [PATCH v1 2/6] clocksource/drivers/exynos_mct: Don't register as a sched_clock on arm64 Will McVicker
2025-03-31 23:40 ` John Stultz
2025-04-01 16:50 ` William McVicker
2025-04-02 1:43 ` Youngmin Nam
2025-03-31 23:00 ` [PATCH v1 3/6] clocksource/drivers/exynos_mct: Set local timer interrupts as percpu Will McVicker
2025-03-31 23:45 ` John Stultz
2025-04-01 16:36 ` William McVicker [this message]
2025-04-02 2:32 ` Youngmin Nam
2025-04-02 22:39 ` William McVicker
2025-03-31 23:00 ` [PATCH v1 4/6] arm64: dts: exynos: gs101: Add 'local-timer-stop' to cpuidle nodes Will McVicker
2025-04-02 4:10 ` Youngmin Nam
2025-04-02 21:59 ` William McVicker
2025-04-03 3:59 ` Youngmin Nam
2025-04-03 18:39 ` William McVicker
2025-04-04 0:02 ` Youngmin Nam
2025-03-31 23:00 ` [PATCH v1 5/6] clocksource/drivers/exynos_mct: Add module support Will McVicker
2025-04-01 2:30 ` Rob Herring
2025-04-01 16:27 ` William McVicker
2025-04-01 6:36 ` Krzysztof Kozlowski
2025-04-01 16:27 ` William McVicker
2025-04-02 4:27 ` Youngmin Nam
2025-03-31 23:00 ` [PATCH v1 6/6] arm64: exynos: Drop select CLKSRC_EXYNOS_MCT Will McVicker
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