From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.alien8.de (mail.alien8.de [65.109.113.108]) (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 C193B39BFF2 for ; Thu, 23 Jul 2026 19:27:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=65.109.113.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784834850; cv=none; b=fsoQKalI2f/lLOi3NkVsCdZQIOIpzVSYGNO0yI4kkU36yrMVVczzae5TjgL0kDWf3CNgRqZ89HLIogFSRZ5CoqMD7M4Zas1gDITpTgP/Z211Sxk3kWBVQj3mBjvk4V85c6G8QEPlxEB0uvrdndE4EMzbygv/T1m3T121aspp0Pw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784834850; c=relaxed/simple; bh=yaLyQUS9alVjzf6d22piUD0asx5ZTTDJi6uZQxeUEbc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dztIDSeRrm6pccUu3ixgQmURQvDdpLpqkRyCP98TaYdQEYTPM6zr/I3hMp6I33DjKw2sGKTSdxOdaL1Aa7XszOEcUIQvKNRVII1If0qaaqo8MlnOJrDv3gtHrE05mEJAW7s/ShkspEErBo50sYXaU5KtTU/tA2Gl9MVLlKplqdg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de; spf=pass smtp.mailfrom=alien8.de; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b=HaJMoURG; arc=none smtp.client-ip=65.109.113.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=alien8.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=alien8.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (4096-bit key) header.d=alien8.de header.i=@alien8.de header.b="HaJMoURG" Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTP id 752D740E00DC; Thu, 23 Jul 2026 19:27:26 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at mail.alien8.de Authentication-Results: mail.alien8.de (amavisd-new); dkim=pass (4096-bit key) header.d=alien8.de Received: from mail.alien8.de ([127.0.0.1]) by localhost (mail.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 7XCgpBV15oF4; Thu, 23 Jul 2026 19:27:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1784834836; bh=aSsU600cegcJqlTi1tNdAN6wt0rtoX7cZevpc8Kcuh0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HaJMoURGFsaAzQsMSY55VPcywJI+Q5hBkCOBCQ/TS1ERFNA8bQFsQmHBhqq6grkMS 28zJ7qG/hUFY6+glAStoynRRB1nso29S03QGgOx7pxosDR8S0zPgk79pl5txhKHSRS CuC/zACdl5gly1c5JM4mmMJfZ3AVzQMwgBU3q28qTa1iksUkP/ByGy0BeGzeEXwN2s cpKMu3MsiVgJPRIVkuSfGRY7Y712T1KK1V8K4CdSGnX8YSILsdtjWfwwqXAMZBUDJL 0x0V6RKhtjjPtS9ThQyRlp/aOXlBmv4FxKumff6gQCECot6ikAMSOQkVd30aA3YQt7 dePV4QV+BIAzVVwveQrj2azYE3o1cv5TPTFFg8VcesKOZvS6cKFOqD39Vb3M8o+ke4 XFfjiEpXdXrMroX31M7rCpN08uuHyONmNyM3v6jwz9cYsMjmj2rtpWFoEfOZceGuur E/NuKDVObmgTJ/SPwuWzjkzRLfcHMm2m7ngIN1dApnFNFuy8DTkbvsDDrYit7nvkqb McJWqx9gnYWpLr+ZPxjHcGOOruJynOBsvxoC6DXdq0MPh51l8V8eADaRkICoI1Il09 sl9YEtlHUOM166M1+/SvL3F39dy6lFrWiZVr17GYYwtbIDs+5j4bd5Bm0axz/T6l0R MriEc0ObuHdb8xe4o0huaPwY= Received: from stx.tnic (unknown [IPv6:2600:1700:38ca:c00::1b]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id BC6B840E00E6; Thu, 23 Jul 2026 19:27:00 +0000 (UTC) Date: Thu, 23 Jul 2026 12:26:57 -0700 From: Borislav Petkov To: Chuyi Zhou Cc: tglx@kernel.org, mingo@redhat.com, luto@kernel.org, peterz@infradead.org, paulmck@kernel.org, muchun.song@linux.dev, dave.hansen@linux.intel.com, pbonzini@redhat.com, bigeasy@linutronix.de, clrkwllms@kernel.org, rostedt@goodmis.org, nadav.amit@gmail.com, vkuznets@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v10 00/14] Allow preemption during IPI completion waiting to improve real-time performance Message-ID: <20260723192657.GBamJrAcb_TCH5Ubog@fat_crate.local> References: <20260709122933.4021501-1-zhouchuyi@bytedance.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <20260709122933.4021501-1-zhouchuyi@bytedance.com> On Thu, Jul 09, 2026 at 08:29:19PM +0800, Chuyi Zhou wrote: > In our production environments, latency-sensitive workloads (DPDK) are > configured with the highest priority to preempt lower-priority tasks at any > time. We discovered that DPDK's wake-up latency is primarily caused by the > current CPU having preemption disabled. Therefore, we collected the maximum > preemption disabled events within every 30-second interval and then > calculated the P50/P99 of these max preemption disabled events: Out of curiosity, can you run your workloads on AMD Zen3 and newer which have TLBI support (this does away with the TLB flush IPIs). Do you see any improvement there? Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette