From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2DFC8FD3760 for ; Wed, 25 Feb 2026 14:58:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=CTVAUSdyonO3o8ZEWCv7RstUu3eRFNm4C0rfrAHcjyE=; b=QRkDc1dceN0CEALuF0vdSjbwUb Z7FnUdPmXc2Gk7gbWs+GrjJ1k9Z1njsHfCTlr0YQUjY+L5E9yuXHrbMazQrtDD6yawX2z4oMfdp8T DPUFHHXUoTv0NEUsQ+iWwB4WHYta0zSu0rMfoE64G8O+LZ1mOzyrlFGLq0sK86Xhq8X8TBpSmERvC S+ZGsuZaFaBa4ZSmsFzL67bGtT1jPnoN7zxGJqlpjknilkxW90UwBxA8G1GlGYWvcgstRtwSsvlgF 3kBpDoNcZoxAx46eQW1bK82KWKC1RbKedF7d1IGnNHWoy+/XLcusiME1B7tQB1DLFDBINdmk8IZgy i7ctnMMg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vvGLX-00000004Ed4-32Ck; Wed, 25 Feb 2026 14:58:39 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vvGLW-00000004EcF-00rr; Wed, 25 Feb 2026 14:58:39 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 2E9A540126; Wed, 25 Feb 2026 14:58:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 910B6C116D0; Wed, 25 Feb 2026 14:58:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772031516; bh=DKswOemgE0o8dLAbtbgTdWvG4rdX6n55NSS0972JIdc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Mdh6iujjSWp6SFz+JwLy4nalaRpHoytaT2mXrTErJdY8ripQ/GKKYsH1b4yAf+HN4 bt2suB/55pPPBWFpqHeD5Wf39lqMh8j/eCfpQ/7ZSOTdklaPGnXI+6N/ciFXt5w7l6 K+AkIiooofhvA2kywZtHdb++EyS59f+F8KnRSR+E2QCR71eqiPfOz0zxuodScZsQkH wYrCJuQhJlMi/x81lK+QlxaMf2EwoNJ8O50o9wHLMBYStJitsqpCEgdFsRfVcbwA/O 5uR2Pq84gRkLCyKcI0lNk99ypfPbGi9rQ6KJc5K/xZf00J+9lmkqkfdjqbP46f6P3S IsjdrQZRFnTNA== Date: Wed, 25 Feb 2026 22:40:00 +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> <20260223091547.GJ136967@e132581.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260223091547.GJ136967@e132581.arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260225_065838_077054_FEFA8369 X-CRM114-Status: GOOD ( 23.26 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Feb 23, 2026 at 09:15:47AM +0000, Leo Yan wrote: > On Sat, Feb 21, 2026 at 08:14:17AM +0800, Jisheng Zhang wrote: > > [...] > > > 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. > > Not true. As said, I tested on CA73. I should say explicitly that I > have hotplugged off CA53 CPUs and run test only on CA73 CPUs. I tested on quad CA73 platform, I can reproduce the abnormal variance as you got. This means the series may not alway improve performance as I expected for *all* CPUs. So I'd like to drop it now. > > > 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