From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9BEEA2AE70; Sat, 21 Feb 2026 00:32:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771633968; cv=none; b=st9jrIU3lpuOzAEnaJETFG0z4Miw+irFVj0tZQM2lB6bHq4Gk/0XWhMLvDZlmfbBavOtNR34/uSZDEqG8l1oRPCu0xWBX98VqcmwtGDaHjtTMA1YXuXIomPBLPn9fBeQMfCaGB8zkzVUKONrrsgNSaLMt/nhi+MKsw67yVWQLdo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771633968; c=relaxed/simple; bh=kwlKI7Kb62LlHiwnwWmHi20ea2Opc01sVtwHb3z1XRw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AQejfGTNLrLrThHDeQDWxD4Yow4fCr5XsOvIvaWQdUxO7gYse6WdcHc7VW9vpzKEvKvudmAG+++qO/VMthuOGWdLdTwjSd5Lw9WplIJ806FaTkM86gGsnjRmTzOf0F4agVQxhIHSerze614z64EqzCYb4aknukt9NdSaw6X5Eb8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tQMkNQ3z; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="tQMkNQ3z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 71CFFC116C6; Sat, 21 Feb 2026 00:32:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771633968; bh=kwlKI7Kb62LlHiwnwWmHi20ea2Opc01sVtwHb3z1XRw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tQMkNQ3zrB9bFmSsQll8RGmasXbrw+cZiGTiWcGGacpVS6Zh+QzSBYwEcNSIvcGEp qa3yMvBKE48mCd0PnjHXqDRCfoxz+EHkCHd+w7rt5xPHxboI163pbPe0PyQL0U4t2X zozPONVkp8Vqn8pmfrv6JAWXBQTy9KvN/o4fHf6pIt8Wt5HtOwYb4S/+nwbp7cKmCE Qzj0vAnqF3g4TGUXuW0me4Cf2GVmjQft9kd3h8nGrN9frsbhXLIm1sdg3yQ1qWT/LR ujpqI506aqQwvCcIqCRbHHAGMOyycQsOZewcFaaedlA3CFjGrGttRpiZkD5fG3UJfW IQBSLT3lqnLNg== Date: Sat, 21 Feb 2026 08:14:17 +0800 From: Jisheng Zhang To: Leo Yan Cc: Catalin Marinas , Will Deacon , Arnd Bergmann , Thomas Gleixner , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Guo Ren , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-riscv@lists.infradead.org, linux-csky@vger.kernel.org Subject: Re: [PATCH 3/3] arm64: use runtime constant to optimize handle_arch_irq access Message-ID: References: <20260220090922.1506-1-jszhang@kernel.org> <20260220090922.1506-4-jszhang@kernel.org> <20260220123414.GF136967@e132581.arm.com> <20260220164738.GH136967@e132581.arm.com> Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260220164738.GH136967@e132581.arm.com> On Fri, Feb 20, 2026 at 04:47:38PM +0000, Leo Yan wrote: > On Fri, Feb 20, 2026 at 09:34:14PM +0800, Jisheng Zhang wrote: > > [...] > > > > > Run 3 iterations, and measures three metrics (messaging/pipe/seccomp) > > > > and results in seconds. Less is better. > > > > > > > > +---------------------+--------+--------+--------+--------+ > > > > |Without change | run1 | run2 | run3 | avg | > > > > +---------------------+--------+--------+--------+--------+ > > > > |messaging (sec) | 4.546 | 4.508 | 4.591 | 4.548 | > > > > |pipe (sec) | 24.258 | 24.224 | 24.017 | 24.166 | > > > > |seccomp-notify (sec) | 48.393 | 48.457 | 48.232 | 48.361 | > > > > +---------------------+--------+--------+--------+--------+ > > > > > > > > +---------------------+--------+--------+--------+--------+--------+ > > > > |With change | run1 | run2 | run3 | avg | diff | > > > > +---------------------+--------+--------+--------+--------+--------+ > > > > |messaging (sec) | 4.493 | 4.523 | 4.556 | 4.524 | +0.52% | > > > > |pipe (sec) | 23.159 | 23.702 | 28.649 | 25.170 | -4.15% | > > > > > > If you check the result, this result variance is abnormal, it means > > > your OS is noiser. > > > > BTW: if you remove the abnormal run3 result, you'll find that the > > benchmark is improved by ~3.5% on CA73: > > (23.159 + 23.702) / 2 = 23.43 > > (24.258 + 24.224) / 2 = 24.24 > > (24.24 - 23.43)*100 / 23.43 = ~3.5 > > TBH, I don't think we should subjectively select data. But I agree a The precondition of this is testing the benchmark properly. And I just tried perf bench sched in noisy OS, I didn't get the similar abnormal variance as you got, so I think your run3 result was CA53's result. This isn't an apple-to-apple comparison. If possible, could you plz test after forcing CA53 offline or test on non big.little platform. Anyway, I will test CA73 next week too. > clean test env is important to avoid noise, and I also agree that the > current results already show positive signals. > > Thanks, > Leo