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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1EED0EB64DD for ; Tue, 8 Aug 2023 01:22:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230403AbjHHBWT (ORCPT ); Mon, 7 Aug 2023 21:22:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229445AbjHHBWQ (ORCPT ); Mon, 7 Aug 2023 21:22:16 -0400 Received: from mail-pl1-x633.google.com (mail-pl1-x633.google.com [IPv6:2607:f8b0:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BD93E5A for ; Mon, 7 Aug 2023 18:22:15 -0700 (PDT) Received: by mail-pl1-x633.google.com with SMTP id d9443c01a7336-1bb84194bf3so33827665ad.3 for ; Mon, 07 Aug 2023 18:22:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1691457734; x=1692062534; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=qdrpnCU+URUIiVCQslFWJZMGyYZvlLsKuoWY8EjeOqw=; b=DVAoA+l+jc4aCXAwCbbTIwkP4CaJuzIqyxBOq2Izr05TzozyFayNyqg1XgWOHvKs1d dRWo26IL8ykTyO5WciiVs9NSSrryu08xLEa6uBCZeZnjGamRpXijWQ0t9qK51bN8Kgz4 wZ0WGFV4EXUFTF8UDIwjAG+476CeyzQTp1yambnWVpAgI713e/VQQni7ix+joAoAdW9b Rfids4EI1QbqqvFFQPfULHzSeavOwav5jPf2tX8r9mqygggQa/6mCr0Xsr91f1GPR/nB Aerur14PfKnKZpYaH0kDAmh1PTK5BTaEU8ZP8AwPtu0KgD5F4CXtz1XVzXtqLRH13Qg9 UfPA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691457734; x=1692062534; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=qdrpnCU+URUIiVCQslFWJZMGyYZvlLsKuoWY8EjeOqw=; b=OKCHTu7ePa7oBvf0uBbCGipAwdf2FmSNEPBFoELBeAvhG0kVq4juE5XNMSDrv54U8T YUWfXBAtgpYrS6iGxFeXwV5vnEY9KRY+MP1GWsUZ8epGtxgFdu2y5JR2Jys+fNZzcSsx XFV156SeCQZq8YWlnXFP3xaefM4c/xaAEudA9rx8RigQOhsOrhU2a0WjDi4nGhJY2u09 2m/ezt62fKHVD4+ZHKp3Hun6+MnmOT0Ojt5CU/uJmo2+8zbPemx0BPjSMTvzK9zOISW0 otUYo9UwFWlO2OVyEAc0uA2Ao9lGbgMYWbTO9pm39y8njJ6AE14UTdBCj+UZuaFma9Ym HHjw== X-Gm-Message-State: AOJu0YypBmOxUfsYQ/LBnxF6J7hRRVEyzjWRsIVoG1IIMdO/wRieRi+X mrpNUKtcB8uALZ3J41Nqpxqhi7Q9eP0= X-Google-Smtp-Source: AGHT+IEYZamFL/O1wGtoFYatSsUq5SrYKvglUQJwJlajxQn24hEQbHrgTxkU8W9mDYFMLGmujEoAuA== X-Received: by 2002:a17:903:24d:b0:1bb:20ee:e29e with SMTP id j13-20020a170903024d00b001bb20eee29emr11939346plh.1.1691457734603; Mon, 07 Aug 2023 18:22:14 -0700 (PDT) Received: from localhost ([2620:10d:c090:400::5:9d5d]) by smtp.gmail.com with ESMTPSA id l4-20020a170903244400b001b89891bfc4sm7516291pls.199.2023.08.07.18.22.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Aug 2023 18:22:14 -0700 (PDT) Sender: Tejun Heo Date: Mon, 7 Aug 2023 15:22:12 -1000 From: Tejun Heo To: jiangshanlai@gmail.com Cc: torvalds@linux-foundation.org, peterz@infradead.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, joshdon@google.com, brho@google.com, briannorris@chromium.org, nhuck@google.com, agk@redhat.com, snitzer@kernel.org, void@manifault.com, kprateek.nayak@amd.com Subject: Re: [PATCHSET v1 wq/for-6.5] workqueue: Improve unbound workqueue execution locality Message-ID: References: <20230519001709.2563-1-tj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230519001709.2563-1-tj@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Thu, May 18, 2023 at 02:16:45PM -1000, Tejun Heo wrote: > Unbound workqueues used to spray work items inside each NUMA node, which > isn't great on CPUs w/ multiple L3 caches. This patchset implements > mechanisms to improve and configure execution locality. The patchset shows minor perf improvements for some but more importantly gives users more control over worker placement which helps working around some of the recently reported performance regressions. Prateek reported concerning regressions with tbench but I couldn't reproduce it and can't see how tbench would be affected at all given the benchmark doesn't involve workqueue operations in any noticeable way. Assuming that the tbench difference was a testing artifact, I'm applying the patchset to wq/for-6.6 so that it can receive wider testing. Prateek, I'd really appreciate if you could repeat the test and see whether the difference persists. Thanks. -- tejun