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 0C349E98E10 for ; Mon, 23 Feb 2026 09:16:03 +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=oH1pEUV4fO/W4+aiaq7ApA6qX6bUSX/6JAcambjFtKA=; b=xsbcE9oB3StgEDZ6W525uypts7 u+hxAxvnhQy9QDbJ8CxXWY6MMc7KMhkJf1zvPYZzfBwwNfdrMeJOcMDI9lLgmmi69Ag5w70b8stc6 DC/G1tEtrL6nW0lOdGopb57ERvMy7g/HPDX74ziq+eG2AUpZNlhQoykb0MqMOXWLqx1SgBRFJ2AyK cuxnBZwhm9mL+4zMGwjWZ+9/SPJkmrHKwIX2JD3rbQuwk6putWk9vGT75ZqepvDwGf3hQYmB9YB2E s82SADM+e461fcJj/yinN5iqRDtHxeNWQgIgIb7BxAPpQ3kbUWRUVRnD3qlMPE33BiyW21whQ1nqU zDS0eXYw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vuS2m-0000000HVx9-22S9; Mon, 23 Feb 2026 09:15:56 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vuS2j-0000000HVw8-3aU0; Mon, 23 Feb 2026 09:15:55 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 04162339; Mon, 23 Feb 2026 01:15:44 -0800 (PST) Received: from localhost (e132581.arm.com [10.1.196.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D54243F62B; Mon, 23 Feb 2026 01:15:49 -0800 (PST) Date: Mon, 23 Feb 2026 09:15:47 +0000 From: Leo Yan To: Jisheng Zhang 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: <20260223091547.GJ136967@e132581.arm.com> References: <20260220090922.1506-1-jszhang@kernel.org> <20260220090922.1506-4-jszhang@kernel.org> <20260220123414.GF136967@e132581.arm.com> <20260220164738.GH136967@e132581.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260223_011553_973390_D10CFEAE X-CRM114-Status: GOOD ( 19.63 ) 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 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. > 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