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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 DD63DC31E51 for ; Tue, 18 Jun 2019 13:40:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ADF1B20873 for ; Tue, 18 Jun 2019 13:40:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="l4aW6nnP"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="XtLSKjLW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729380AbfFRNkd (ORCPT ); Tue, 18 Jun 2019 09:40:33 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:53392 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727584AbfFRNkc (ORCPT ); Tue, 18 Jun 2019 09:40:32 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 9A48F60A00; Tue, 18 Jun 2019 13:40:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1560865231; bh=3S920kb9n9ahqKRzh5GewJNZfwKu57RH7nMn5VmTegs=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=l4aW6nnPwElZx+0tcypQKi7XbSu6KOxNtbIfky2jofdFgmEUfQqXjEwvRwQR24N7J +FEhGWq3Q+zdbl68+wCqqK8k5nNx3LJnItZEW2JDY6MmXoljFxjsq/A8ZJBuipwLlL XjLxPCa66cilnVCEN43ACwh0BSd2qbDkpY8KBZr8= Received: from [10.204.79.15] (blr-c-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.19.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: mojha@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 64D4060A00; Tue, 18 Jun 2019 13:40:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1560865227; bh=3S920kb9n9ahqKRzh5GewJNZfwKu57RH7nMn5VmTegs=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=XtLSKjLWrLutIGH8KwFxjxolWP6E5fuG4T9J870AB6WdXIVg5pfxa4gyAyTQ7WTWp ahuSaYp9ihiEQVDisIqsmz0CUG6ePwoq2ECYZ/+o99JdQLHEuFKc1AI8/d/mLGOEDX hz8H/kQZWGOxB9+59FW14lzmDNMvtUPvvRDKcZ0I= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 64D4060A00 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=mojha@codeaurora.org Subject: Re: [PATCH V4] perf: event preserve and create across cpu hotplug To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Raghavendra Rao Ananta , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Jiri Olsa , Alexei Starovoitov References: <1560337045-13298-1-git-send-email-mojha@codeaurora.org> <1560848091-15694-1-git-send-email-mojha@codeaurora.org> <20190618122329.GE3419@hirez.programming.kicks-ass.net> From: Mukesh Ojha Message-ID: Date: Tue, 18 Jun 2019 19:10:13 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190618122329.GE3419@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/18/2019 5:53 PM, Peter Zijlstra wrote: > On Tue, Jun 18, 2019 at 02:24:51PM +0530, Mukesh Ojha wrote: >> Perf framework doesn't allow preserving CPU events across >> CPU hotplugs. The events are scheduled out as and when the >> CPU walks offline. Moreover, the framework also doesn't >> allow the clients to create events on an offline CPU. As >> a result, the clients have to keep on monitoring the CPU >> state until it comes back online. >> >> Therefore, > That's not a therefore. There's a distinct lack of rationale here. Why > do you want this? Thanks Peter for coming back on this. Missed to send the coverletter, https://lkml.org/lkml/2019/5/31/438 Will resend this with coverletter. Btw,  This patch is based on suggestion given by you on this https://lkml.org/lkml/2018/2/16/763 Thanks. Mukesh Thanks. Mukesh