linux-kernel - Re: [PATCH v5 13/20] x86/mce: Unify AMD THR handler with MCA Polling

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Message-ID: <20250902111052.GDaLbQvA2A0b8Ii26k@fat_crate.local>
Date: Tue, 2 Sep 2025 13:10:52 +0200
From: Borislav Petkov <bp@...en8.de>
To: Yazen Ghannam <yazen.ghannam@....com>
Cc: x86@...nel.org, Tony Luck <tony.luck@...el.com>,
	"Rafael J. Wysocki" <rafael@...nel.org>,
	linux-kernel@...r.kernel.org, linux-edac@...r.kernel.org,
	Smita.KoralahalliChannabasappa@....com,
	Qiuxu Zhuo <qiuxu.zhuo@...el.com>,
	Nikolay Borisov <nik.borisov@...e.com>, linux-acpi@...r.kernel.org
Subject: Re: [PATCH v5 13/20] x86/mce: Unify AMD THR handler with MCA Polling

On Mon, Aug 25, 2025 at 05:33:10PM +0000, Yazen Ghannam wrote:
> +/*
> + * Threshold interrupt handler will service THRESHOLD_APIC_VECTOR. The interrupt
> + * goes off when error_count reaches threshold_limit.
> + */
> +static void amd_threshold_interrupt(void)
> +{
> +	machine_check_poll(MCP_TIMESTAMP, &this_cpu_ptr(&mce_amd_data)->thr_intr_banks);
>  }

So the thresholding interrupt will fire.

It'll call machine_check_poll().

That thing will do something and eventually call back into amd.c again:

                if (mce_flags.amd_threshold)
                        amd_reset_thr_limit(i);

Why the back'n'forth?

Why not:

static void amd_threshold_interrupt(void)
{
	machine_check_poll(MCP_TIMESTAMP, &this_cpu_ptr(&mce_amd_data)->thr_intr_banks);
	amd_reset_thr_limit();
}

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette