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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 11CE4C04AB6 for ; Tue, 28 May 2019 16:17:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D42F921721 for ; Tue, 28 May 2019 16:17:00 +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="m6MP/xrw"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="hvwoMvcF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727326AbfE1QRA (ORCPT ); Tue, 28 May 2019 12:17:00 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:35082 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726371AbfE1QQ7 (ORCPT ); Tue, 28 May 2019 12:16:59 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 387BF6188E; Tue, 28 May 2019 16:16:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1559060219; bh=NZZxhr/Jde6iwR3plkTJWmJgNv290hmJqEH8yoF/dOE=; h=Subject:From:To:Cc:References:Date:In-Reply-To:From; b=m6MP/xrw8LbKlYy3Am484x8NVoogtjAdQFQ+SzkWdvbl79o3tCdAqu7ogk7klXSZz pXmW1gxlX3iPEFqgdD27SqqldFkWvqOHTiDLCW3gu/1U3ZIobYyrMLjSUZLR9f5PYz eehn9QsUmbMDxqS2cJyYV7o8j9xS2Z3+XnMoct+c= 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 582FC61B6A; Tue, 28 May 2019 16:16:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1559060212; bh=NZZxhr/Jde6iwR3plkTJWmJgNv290hmJqEH8yoF/dOE=; h=Subject:From:To:Cc:References:Date:In-Reply-To:From; b=hvwoMvcFHdinPmCvtky2U3w5mqiaWtS3H3yzP01VpBZSHg5+52w1o8bVxGgUvjUpT eCQSnnm4+T4wXCp8co+a46KYttuBX5oKproWtJfqnbIAzPkbAIM+kmBVPEk5XyswvU b85ufxgfXFz5Wv3xExY6mZ3L43Yp3fJM+6TKoDag= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 582FC61B6A 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: Perf: Preserving the event across CPU hotunplug/plug and Creation of an event on offine CPU From: Mukesh Ojha To: Peter Zijlstra Cc: lkml , Thomas Gleixner References: Message-ID: <4f276f87-b6d8-f868-b3e7-9951d1383070@codeaurora.org> Date: Tue, 28 May 2019 21:46:42 +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: 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 Friendly Ping. On 5/23/2019 6:39 PM, Mukesh Ojha wrote: > Hi Peter/All, > > This is regarding the discussion happen in the past about > https://lkml.org/lkml/2018/2/15/1324 > > Where the exact ask is to allow preserving and creation of events on a > offline CPU, so that when the CPU > comes online it will start counting. > > I had a look at your patch too and resolve crash during while trying > to create an event on an offline cpu. > > In your patch,  you seem to disable event when cpu goes offline which > is exactly deleting the event > from the pmu and add when it comes online, it seems to  work. > > But, For the purpose of allowing the creation of event while CPU is > offline is not able to count event while > CPU coming online, for that i did some change, that did work. > > Also, I have query about the events which gets destroyed while CPU is > offline and we need to remove them > once cpu comes online right ? As Raghavendra also queried the same in > the above thread. > > Don't we need  a list where we maintain the events which gets > destroyed while CPU is dead ? > and clean it  up when CPU comes online ? > > Thanks. > Mukesh > >