From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=213.97.179.56 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793705816; b=WY1EkiI3ZVt4U9N4IzssODucPmCpNja49ouzPV8QIOT6LBWbywYSiKbQwogLwyyoJ5iu iDEvldvMwM3cnBy7cOU23Rsg357w7Ow0xWdpKohG2EpBSV9aEtNu/QWsv31wUJDZG/2nn y4EzuZIRoyDOJ6NsGKi0voBpx7T3+U0Ck/H1qhjNuF5/wGiIxcHqUVSHbFeaJ+cK2Dl3o dmiG5jlPs5R80qLcSLL6j1zTc+ZY2fljtF0v6vGLO9ymma6EVXVlvVMyWe/77v33z66qd DfMNDzN4gOQzg0tEeLGOVZTxcn0wCz4sWqVt4DGWsOEtAbrpcf3Orw1+HhtHG+J+6Pg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793705816; h=DMARC-Filter:DKIM-Signature:Received:Message-ID:Date:MIME-Version: User-Agent:Subject:To:Cc:References:Content-Language:From:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=tP0eDm+K+Ts1AokzxU+OQjzFfPfzGLzzVFeOKFJstP0=; b=XJHGns3RuVN8xXoPGJ1d/ok1fvnZVA41xeOYT4I9NVfjC+q7dlcPzNxBcdtd4IisIF8W oOUoEuUJZhK+BXhaWAZdtmR+D9srl8G4o6dqtMypOvaB4UNL+5NPnuWHGV2QE2TEE7AlF RDX516Emqxqw7rc3yPPY2Kl73t4/T6OUb7uGPfaCZEBU7z6djaIjmuxPW5sp/tRuwvOPv cU0KX42v4T4GZ7WhwFe+TLRg2LsrQnp2FoPIp8KxavdztW9Qj3jPyYarNt86DAsnYJ/bV O6Wd+PpEwvODdgt8e/9t2FY+x7YOx2wSz8ajQjvIgfypBiIhYXt6MD3FbAKzOmrGvvw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass header.d=igalia.com header.i=@igalia.com header.a=rsa-sha256 header.s=20170329 header.b=A+AsFA6y; arc=none smtp.remote-ip=213.97.179.56 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 63FA2606D80D for ; Tue, 3 Nov 2026 11:36:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 63FA2606D80D Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=igalia.com header.i=@igalia.com header.a=rsa-sha256 header.s=20170329 header.b=A+AsFA6y DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:From:Cc:To:Subject: MIME-Version:Date:Message-ID:From:Reply-To; bh=tP0eDm+K+Ts1AokzxU+OQjzFfPfzGLzzVFeOKFJstP0=; t=1793705815; x=2109065815; b=A+AsFA6yyhWIwKvxp9kD8jfPSj6GxBMTz+UTsEjZioton9vsFerthXTjgzou3GmatDXDSRzjHK+ r2x3Z1n9qzZoJfpzmxhDNzRieETZ/aZyOkluDhX2QIVna63JVaj0/xP7B+W0aMxijEZvaLO1d4J5a KUuyy6vCFpOPga8z+06VWk7gGqm8SHOej3QzMO3pnSKDA2FpOOpJGdg1Y/fEpzgQtK5n/9p4ito2v M98SYZoBi6IrHGU/Fry7UJA23BdAeKWY7MVwZ2SoaHAlINyxrsoYSnLm+mXyQXYE/oxvt0osxz0dI nSRVhF4Fblzyx3Yy87YmNkEUyVvpLGKWxAiA==; Received: from [81.79.79.1] (helo=[192.168.0.116]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_128_GCM:128) (Exim) id 1xOCos-001AIl-PT; Tue, 03 Nov 2026 12:36:50 +0100 Message-ID: <9c0fcefa-a40f-4e01-8fab-c079d4697397@igalia.com> Date: Tue, 3 Nov 2026 11:36:49 +0000 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 3/4] workqueue: Add support for real-time workers To: Tejun Heo Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, kernel-dev@igalia.com, Boris Brezillon , Bradley Morgan , Chia-I Wu , Liviu Dudau , Matthew Brost , Steven Price , Lai Jiangshan , Breno Leitao References: <20261022093848.5727-1-tvrtko.ursulin@igalia.com> <20261022093848.5727-4-tvrtko.ursulin@igalia.com> <9d6add80-2ec9-4f29-a815-ad0e955f7b5a@igalia.com> <7fec5fa8362328bf3356a077a8bd9687@kernel.org> Content-Language: en-GB From: Tvrtko Ursulin In-Reply-To: <7fec5fa8362328bf3356a077a8bd9687@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 26/10/2026 18:37, Tejun Heo wrote: > Hello, Tvrtko. > > On Sat, Oct 24, 2026 at 09:33:42AM +0100, Tvrtko Ursulin wrote: >> Can do. I'll get to it the week after next. (Tweaks to other patches in >> the series as well.) Should I switch to a different base branch by then? > > I just branched wq/for-7.5. That should work as the base. > >> But if you are curious how much better strict >> affinity makes them I can measure, it is not a huge effort. > > Yes, numbers with and without strict affinity would be great. Re-measured submit latencies on three relevant setups: us 7.3.0 WQ_RT +strict_affinity median 30 21 11 min 2 3 2 max 1038 941 108 95pct 2384 49 28 98pct 2922 63 51 I suppose we can interpret this in two ways. Plain WQ_RT is already a huge improvement, and although strict affinity is even better, the twice as good median probably isn't a huge selling point. So question is do tail latencies above the 98th percentile matter, or are they visible in the user experience. That I have no experience to answer. FWIW I have locally split out the patch which adds strict affinity on top of WQ_RT so we can trivially go either way. >> Hmm.. I could do that, but since the tool ships within the kernel does >> it _need_ to have backward compatibility regarding kernel _internal_ >> implementation details? > > It's just a nice-to-have, but other parts of the script already support > older kernels, so falling back would be good if it doesn't add too much > complexity. Okay done. Regards, Tvrtko