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 20D77C433F5 for ; Wed, 30 Mar 2022 17:05:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349180AbiC3RHR (ORCPT ); Wed, 30 Mar 2022 13:07:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243512AbiC3RHK (ORCPT ); Wed, 30 Mar 2022 13:07:10 -0400 Received: from mail-yw1-x112f.google.com (mail-yw1-x112f.google.com [IPv6:2607:f8b0:4864:20::112f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8892FDFB1 for ; Wed, 30 Mar 2022 10:05:24 -0700 (PDT) Received: by mail-yw1-x112f.google.com with SMTP id 00721157ae682-2e6650cde1bso225761147b3.12 for ; Wed, 30 Mar 2022 10:05:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=AnsMD3FeYrTSlZn/a95b13cN6i0RSdBp2eSDDvoNOW0=; b=m55c1Vo4NWO0XDeAhLWxHXUHuwrAsIGj84rayCYgL6T0n1akynub8GAmHZSisi9osc PPTJ3l+EEy5cwXW1L6B6dBQWmIKry6b825eb1HSbDaPVq3gsJKj9pIFTrSWD26JXY5zf lUMszNHBX65MANiU/Js2C8PbuB5ZFme/bUMfH+D2qaaO/J+2FHXjb8MmlO1qPq+Cl1gZ NCqcrCgG4jooxaNWO3iEkYNP0TUO335EFU7W5pTqyKXCtlfS+Onm4iDnvAJTnFrH7epu 192bba5ezqTQh4FkbVBy1bOOgyPItROWRnKxaIFgDnCo4MgS2Dp9qNDdysOo77ttlCM7 Ztug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=AnsMD3FeYrTSlZn/a95b13cN6i0RSdBp2eSDDvoNOW0=; b=huMkR5mpL5ZDzxAJHI1LlRWgdzT+DYVtYDK+HOTOCpaj7uut7Duw9rVM8l42sX0jpp LWbnVnR+8KiAwMrlOZqCvrY08WUtueVVwQf2Kytfjzt0T/7A4ETfVx4bX3mhi5U9Dss3 8QPorTM//GSiZ1K02g1UdYkQL+Quljk18X6fCnyIxuHvucju3HgN+LiAJWstHwMJ5pIQ EI9BbbhEBzDhEyVwwC+KMlHVNfqozkjRDMBi/KwMFtVrKxkWLJ6CvN6YoDDSUwLFff9r ynEKRaD6TQ6uWscEIPDkSgVdaySWRIxu73jDaOUObZkL1EqTbu181QnkIUG35NO8UY0c y8yA== X-Gm-Message-State: AOAM532OhqTF6n3yfwi0+YlT+xYvR5IV/LM2OYm7Yq8z/qmHTqaJugUQ 65CM/V4RcS5wuHyzJq+sMh80zYsBw7PRpdqN3I2U6g== X-Google-Smtp-Source: ABdhPJz32aJueOZgkKLfvPFmTlmVPA1/UHHHoFUDQWBSedXE1xVeQq6hAhVxGzYPOXM9ST+h1IUfbxPABosm4dr9p0o= X-Received: by 2002:a81:1693:0:b0:2e5:874a:c060 with SMTP id 141-20020a811693000000b002e5874ac060mr593477yww.489.1648659923411; Wed, 30 Mar 2022 10:05:23 -0700 (PDT) MIME-Version: 1.0 References: <20220311011715.2440601-1-eric.dumazet@gmail.com> <87ee2jo2je.ffs@tglx> <87bkxnnzkj.ffs@tglx> In-Reply-To: <87bkxnnzkj.ffs@tglx> From: Eric Dumazet Date: Wed, 30 Mar 2022 10:05:12 -0700 Message-ID: Subject: Re: [PATCH] x86/cpu: use smp_call_function_many() in arch_freq_prepare_all() To: Thomas Gleixner Cc: Eric Dumazet , "Paul E . McKenney" , linux-kernel , "Rafael J . Wysocki" , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , "the arch/x86 maintainers" , Peter Zijlstra Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 30, 2022 at 10:02 AM Thomas Gleixner wrote: > > On Wed, Mar 30 2022 at 09:51, Eric Dumazet wrote: > > On Wed, Mar 30, 2022 at 8:58 AM Thomas Gleixner wrote: > >> which I hate with a passion because that allows *unpriviledged* user > >> space to inject systemwide IPIs every 10ms just to read these counters > >> which are providing not more than some estimate and are of no value for > >> the only sane use case of /proc/cpuinfo, i.e. #1 above. > > > > You do realize that before my patch, this is already happening ? > > > > My "optimization" simply replace an open loop of individual IPI with > > use of the broadcast IPI capability. > > > > Are you saying we should remove IPI broadcast and use loops > > of IPI, one cpu at a time ? > > I rather have no IPIs at all... Can you send an actual patch, with a changelog then ? I saw kind of a rant about my patch, which was fine IMO. Sorry.