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 X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BC860C433B4 for ; Fri, 30 Apr 2021 13:11:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8AA2A61481 for ; Fri, 30 Apr 2021 13:11:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232499AbhD3NLu (ORCPT ); Fri, 30 Apr 2021 09:11:50 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:49422 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231696AbhD3NLt (ORCPT ); Fri, 30 Apr 2021 09:11:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619788260; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=eFmN7GXhyvWoD/0hmIYm1FOaJDGHK8SDles6jaDUx50=; b=Roz6MQuvSjtJ36aHxa5jdtoHbhw6nn5qVcVsCPlEyP6roT8dQZ49pax45RBdhX7MnalPg+ x9nV9r49LzNY1dg6iKKHIW62n6VTxPd5exLgjDZODvt3soKc3qSZQ3a6afSqrPddENUzBG kearsYv13LoUgNiJlsZ7Oi9efvQgmL0= Received: from mail-lj1-f198.google.com (mail-lj1-f198.google.com [209.85.208.198]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-438-PzdFpoL1PIK7X1NukTJT_g-1; Fri, 30 Apr 2021 09:10:56 -0400 X-MC-Unique: PzdFpoL1PIK7X1NukTJT_g-1 Received: by mail-lj1-f198.google.com with SMTP id a18-20020a2eb5520000b02900beebb1aa69so17195764ljn.12 for ; Fri, 30 Apr 2021 06:10:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=eFmN7GXhyvWoD/0hmIYm1FOaJDGHK8SDles6jaDUx50=; b=QifV4yhESNfJimWQIlA/Ui+X4oAP93D8JZl2V/0BtLeqvx3W2PBBwBBAJvgBj3iaip 32NEIhOnWkUCEurshAEe8o4YcQ8X7+jFSv+yL6n2ylp1wq6QQ75MPqowY23fFUiySfyb TdLCysvH/sWK8YWjQ3JFzJ37YVfyVhPZjdo6OGTtXX7Iez3+8MK4++iueYXOvR3g0DL3 JbI/nppb6PmUUYYfnHLa1P8phbPxUU1XrX8wh4KeDz+fFTOw5vkDe9H5yAfv3jrrfVhv aQe85yLmeUGjcmNynerd8l05btLiVHMsi5gIsVLnsT0o8fcCWEgCy0IQvvFcOprdsp3F 8DIA== X-Gm-Message-State: AOAM530gwTx+XAkpCrE9HP9/SojkZ6yaTfCElSkU+nrD3HtJ77NNE92I cFnFhsyUmvXcyJth5tlEVKabM6qvBbiXvn1AgANeNE5K67q+Pz4kVJC+uqfxtkJCKY5vyJc1kY5 shTAjd6K/K63UZX1nl/Myv/eXHNGU1Rsacmwb X-Received: by 2002:a2e:a71e:: with SMTP id s30mr3619813lje.137.1619788255165; Fri, 30 Apr 2021 06:10:55 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyJqc1hlP2rkr8JKdzvyVvOdVHZomdQvDwhT1frYVIrIzVVBNex0m3GwjpZjhRo3TTecIKglydEAUtmkI34+Ic= X-Received: by 2002:a2e:a71e:: with SMTP id s30mr3619779lje.137.1619788254917; Fri, 30 Apr 2021 06:10:54 -0700 (PDT) MIME-Version: 1.0 References: <20200625223443.2684-1-nitesh@redhat.com> <20200625223443.2684-2-nitesh@redhat.com> <3e9ce666-c9cd-391b-52b6-3471fe2be2e6@arm.com> <20210127121939.GA54725@fuller.cnet> <87r1m5can2.fsf@nanos.tec.linutronix.de> <20210128165903.GB38339@fuller.cnet> <87h7n0de5a.fsf@nanos.tec.linutronix.de> <20210204181546.GA30113@fuller.cnet> <20210204190647.GA32868@fuller.cnet> <87y2g26tnt.fsf@nanos.tec.linutronix.de> <7780ae60-efbd-2902-caaa-0249a1f277d9@redhat.com> <07c04bc7-27f0-9c07-9f9e-2d1a450714ef@redhat.com> <20210406102207.0000485c@intel.com> <1a044a14-0884-eedb-5d30-28b4bec24b23@redhat.com> <20210414091100.000033cf@intel.com> <54ecc470-b205-ea86-1fc3-849c5b144b3b@redhat.com> <20210429184802.0000641e@intel.com> In-Reply-To: <20210429184802.0000641e@intel.com> From: Nitesh Lal Date: Fri, 30 Apr 2021 09:10:40 -0400 Message-ID: Subject: Re: [Patch v4 1/3] lib: Restrict cpumask_local_spread to houskeeping CPUs To: Jesse Brandeburg Cc: Thomas Gleixner , "frederic@kernel.org" , "juri.lelli@redhat.com" , Marcelo Tosatti , abelits@marvell.com, Robin Murphy , "linux-kernel@vger.kernel.org" , "linux-api@vger.kernel.org" , "bhelgaas@google.com" , "linux-pci@vger.kernel.org" , "rostedt@goodmis.org" , "mingo@kernel.org" , "peterz@infradead.org" , "davem@davemloft.net" , "akpm@linux-foundation.org" , "sfr@canb.auug.org.au" , "stephen@networkplumber.org" , "rppt@linux.vnet.ibm.com" , "jinyuqi@huawei.com" , "zhangshaokun@hisilicon.com" , netdev@vger.kernel.org, chris.friesen@windriver.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Thu, Apr 29, 2021 at 9:48 PM Jesse Brandeburg wrote: > > Nitesh Lal wrote: > > > @Jesse do you think the Part-1 findings explain the behavior that you have > > observed in the past? > > > > Also, let me know if there are any suggestions or experiments to try here. > > Wow Nitesh, nice work! That's quite a bit of spelunking you had to do > there! > > Your results that show the older kernels with ranged affinity issues is > consistent with what I remember from that time, and the original > problem. That's nice. > > I'm glad to see that a) Thomas fixed the kernel to even do better than > ranged affinity masks, and that b) if you revert my patch, the new > behavior is better and still maintains the fix from a). Right, the interrupts are naturally spread now. > > For me this explains the whole picture and makes me feel comfortable > with the patch that reverts the initial affinity mask (that also > introduces a subtle bug with the reserved CPUs that I believe you've > noted already). > Thank you for confirming! -- Nitesh