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=1.0 required=3.0 tests=DKIM_SIGNED,FSL_HELO_FAKE, MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID,USER_AGENT_MUTT 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 5DA34C433F5 for ; Mon, 10 Sep 2018 10:03:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 13FD42086E for ; Mon, 10 Sep 2018 10:03:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="R7SHtIhh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 13FD42086E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728089AbeIJO4X (ORCPT ); Mon, 10 Sep 2018 10:56:23 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:37470 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727781AbeIJO4X (ORCPT ); Mon, 10 Sep 2018 10:56:23 -0400 Received: by mail-wm0-f67.google.com with SMTP id n11-v6so20693274wmc.2 for ; Mon, 10 Sep 2018 03:03:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=nrp/LzQCHtlfiL6Q32QcL2jgzBICyLoJno5frRBkNL4=; b=R7SHtIhhajJHa1BureKYcRNUm33TAUgz0Wp1j/je1kCt8NVHVaFwihvC9QP7WG9uOR Ao2Ol1RTmi4y0yAQZdmEo50eYS37JksxLr4dAQk3dgs8iqGmYZ2gypyxO3gHAGNSOFMQ 6vJiJyw/CtKiNWfRCFhaM6Htk4gXDmaiG6kB13mJ8flFqw/2idcF3lX9G+BlDuLr3hMy Mjl9SFpy7xNV5SLxN0r6yECS7MFj0c+6SBjCieE4eIOw181nNdw555mBWvulgkdN8KOh OEPd8s+qJ2n1hgKKDjC7B9aSxJigi+ITpsViPQ0UX5I7iENcO9M2CiZ93+ofjGyxjhv6 DTxw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=nrp/LzQCHtlfiL6Q32QcL2jgzBICyLoJno5frRBkNL4=; b=epbiogCQ8vKpCuybY/zIU3ZLhGD0ed6/+bMplTiMNo1QJGj6wpzcPYWBnOx8KFs4Ex Dnf25MI9eL7/HU9xO+vluRbzhjk/v7e+HH8HB0Uzk1jyPdWB/JLop6mnx6KbKHmVvo6s w/pJ7kYUK2mb+Qk7uoxGmDkYIJK32ftcRpXGJOxRWIi15f+NJVpHOKF4JHN1BHIdjKvo VitmCMOMe43iWUpsI1GLnojIdXjGVUfYxgFB0IDv1hjTP92k4ElrfCL4DpEgfbf9mtP/ glDyDdLFojUPPIgcvagXQyE/mJ2oXfsgK97ClJ7piv/pJhHW6PJRm2VkQoyN/kq2mwZD gI6Q== X-Gm-Message-State: APzg51CodoEG52qeVEG7HgI85OdEbk7PwUVnFnLIw08o7nsELsM9gDjl ta1ZWUTJZZOf39TddRpVomc= X-Google-Smtp-Source: ANB0VdZyt+TKyFIgKlmsH4CAbL7pLll8pSR9oEo7qxSd87YhAmU8RjrZSVqgYEXmPjPVQygRnHCrMA== X-Received: by 2002:a1c:7305:: with SMTP id d5-v6mr158078wmb.53.1536573786043; Mon, 10 Sep 2018 03:03:06 -0700 (PDT) Received: from gmail.com (2E8B0CD5.catv.pool.telekom.hu. [46.139.12.213]) by smtp.gmail.com with ESMTPSA id h73-v6sm46906042wma.11.2018.09.10.03.03.04 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 10 Sep 2018 03:03:05 -0700 (PDT) Date: Mon, 10 Sep 2018 12:03:03 +0200 From: Ingo Molnar To: Jiri Olsa Cc: Alexey Budankov , Peter Zijlstra , Arnaldo Carvalho de Melo , Alexander Shishkin , Namhyung Kim , Andi Kleen , linux-kernel Subject: Re: [PATCH v8 0/3]: perf: reduce data loss when profiling highly parallel CPU bound workloads Message-ID: <20180910100303.GA101776@gmail.com> References: <20180910091841.GA4664@gmail.com> <20180910095909.GA15548@krava> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180910095909.GA15548@krava> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Jiri Olsa wrote: > > Per-CPU threading the record session would have so many other advantages as well (scalability, > > etc.). > > > > Jiri did per-CPU recording patches a couple of months ago, not sure how usable they are at the > > moment? > > it's still usable, I can rebase it and post a branch pointer, > the problem is I haven't been able to find a case with a real > performance benefit yet.. ;-) > > perhaps because I haven't tried on server with really big cpu > numbers Maybe Alexey could pick up from there? Your concept looked fairly mature to me and I tried it on a big-CPU box back then and there were real improvements. Thanks, Ingo