Re: [RFC PATCH 00/14] Introducing TIF_NOTIFY_IPI flag

From: Linus Walleij <linus.walleij@linaro.org>
To: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: linux-kernel@vger.kernel.org,
	"Gautham R. Shenoy" <gautham.shenoy@amd.com>,
	 Richard Henderson <richard.henderson@linaro.org>,
	Russell King <linux@armlinux.org.uk>,
	 Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	 Juri Lelli <juri.lelli@redhat.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	 Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Ard Biesheuvel <ardb@kernel.org>,  Arnd Bergmann <arnd@arndb.de>,
	x86@kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC PATCH 00/14] Introducing TIF_NOTIFY_IPI flag
Date: Wed, 6 Mar 2024 10:44:50 +0100	[thread overview]
Message-ID: <CACRpkdbxjU0r+PDTxJwrgzuJgaKnOCHtkaZtm4jO6bmFQ0SPiQ@mail.gmail.com> (raw)
In-Reply-To: <20240220171457.703-1-kprateek.nayak@amd.com>

Hi K Prateek,

I trimmed down the recipient list so we don't bounce.

On Tue, Feb 20, 2024 at 6:15 PM K Prateek Nayak <kprateek.nayak@amd.com> wrote:

> Same experiment was repeated on an dual socket ARM server (2 x 64C)
> which too saw a significant improvement in the ipistorm performance:
>
>   ==================================================================
>   Test          : ipistorm (modified)
>   Units         : Normalized runtime
>   Interpretation: Lower is better
>   Statistic     : AMean
>   ==================================================================
>   kernel:                               time [pct imp]
>   tip:sched/core                        1.00 [0.00]
>   tip:sched/core + TIF_NOTIFY_IPI       0.41 [59.29]

Is that a 64bit ARM64 system or really an ARM 32-bit 64-core system?

I'm confused because:

> K Prateek Nayak (10):
>   arm/thread_info: Introduce TIF_NOTIFY_IPI flag

There is no arm64 patch in the patch series.

I can perhaps test the patches on an ARM32 system but all I have is dualcore
I think.

Yours,
Linus Walleij