From: Will Deacon <will@kernel.org>
To: Tomohiro Misono <misono.tomohiro@fujitsu.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Jonathan Corbet <corbet@lwn.net>,
Shuah Khan <skhan@linuxfoundation.org>,
Randy Dunlap <rdunlap@infradead.org>,
Marc Zyngier <maz@kernel.org>, Thomas Gleixner <tglx@kernel.org>,
Radu Rendec <radu@rendec.net>,
Kohei Enju <enju.kohei@fujitsu.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
linux-perf-users@vger.kernel.org
Subject: Re: [PATCH 3/4] perf: arm_pmu: Add workaround for FUJITSU-MONAKA Erratum E#030002
Date: Fri, 2 Oct 2026 13:44:44 +0100 [thread overview]
Message-ID: <ar-nPJyVzPcvbICa@willie-the-truck> (raw)
In-Reply-To: <20261002-monaka-fix-for-upstream-v1-3-4aec0b0cbe34@fujitsu.com>
On Fri, Oct 02, 2026 at 07:26:51PM +0900, Tomohiro Misono wrote:
> FUJITSU-MONAKA Erratum E#030002 affects FUJITSU-MONAKA CPU.
>
> On affected FUJITSU-MONAKA CPUs, after a PMU event counter is
> stopped at a value just before overflow, an overflow might still
> be incorrectly detected, resulting interrupt storm in some case.
>
> Work around the erratum by avoiding programming PMU event counters
> with values within five counts of overflow.
What's the user-visible behaviour of this erratum? It's not entirely clear
to me why we need to do anything at all.
Will
next prev parent reply other threads:[~2026-10-02 12:44 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-02 10:26 [PATCH 0/4] arm64: Add workarounds for FUJITSU-MONAKA CPU Tomohiro Misono
2026-10-02 10:26 ` [PATCH 1/4] arm64: cputype: Add FUJITSU MONAKA definition Tomohiro Misono
2026-10-02 10:31 ` sashiko-bot
2026-10-02 10:26 ` [PATCH 2/4] arm64: tlb: Add tlbi workaround for FUJITSU-MONAKA Erratum E#030001 Tomohiro Misono
2026-10-02 10:41 ` sashiko-bot
2026-10-02 12:43 ` Will Deacon
2026-10-06 9:48 ` Tomohiro Misono (Fujitsu)
2026-10-02 13:01 ` Mark Rutland
2026-10-06 9:45 ` Tomohiro Misono (Fujitsu)
2026-10-02 10:26 ` [PATCH 3/4] perf: arm_pmu: Add workaround for FUJITSU-MONAKA Erratum E#030002 Tomohiro Misono
2026-10-02 10:35 ` sashiko-bot
2026-10-02 12:44 ` Will Deacon [this message]
2026-10-06 9:52 ` Tomohiro Misono (Fujitsu)
2026-10-02 10:26 ` [PATCH 4/4] irqchip/gicv3: Add workaround for FUJITSU-MONAKA erratum E#030003 Tomohiro Misono
2026-10-02 10:41 ` sashiko-bot
2026-10-07 11:37 ` Kohei Enju
2026-10-02 12:26 ` Marc Zyngier
2026-10-06 9:08 ` Kohei Enju
2026-10-06 9:42 ` Marc Zyngier
2026-10-07 8:17 ` Kohei Enju
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