From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751374AbeEDLDY (ORCPT ); Fri, 4 May 2018 07:03:24 -0400 Received: from 9pmail.ess.barracuda.com ([64.235.150.225]:46354 "EHLO 9pmail.ess.barracuda.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751114AbeEDLDW (ORCPT ); Fri, 4 May 2018 07:03:22 -0400 Subject: Re: [RFC PATCH] MIPS: Oprofile: Drop support To: Robert Richter CC: James Hogan , Ralf Baechle , , Huacai Chen , , Jiaxun Yang , Krzysztof Kozlowski , References: <1524574554-7451-1-git-send-email-matt.redfearn@mips.com> <20180424130511.GB28813@saruman> <5e464a40-4e4d-dde4-b5b5-ceb637dc5f38@mips.com> <20180504093002.GC4493@rric.localdomain> <20180504102600.GD4493@rric.localdomain> From: Matt Redfearn Message-ID: <294858af-9164-f0c3-62d3-d6b643e89e09@mips.com> Date: Fri, 4 May 2018 12:03:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180504102600.GD4493@rric.localdomain> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.155.41] X-ClientProxiedBy: mipsdag02.mipstec.com (10.20.40.47) To mipsdag02.mipstec.com (10.20.40.47) X-BESS-ID: 1525431771-637139-31429-47751-1 X-BESS-VER: 2018.5-r1804261738 X-BESS-Apparent-Source-IP: 12.201.5.32 X-BESS-Outbound-Spam-Score: 0.00 X-BESS-Outbound-Spam-Report: Code version 3.2, rules version 3.2.2.192687 Rule breakdown below pts rule name description ---- ---------------------- -------------------------------- 0.00 BSF_BESS_OUTBOUND META: BESS Outbound X-BESS-Outbound-Spam-Status: SCORE=0.00 using account:ESS59374 scores of KILL_LEVEL=7.0 tests=BSF_BESS_OUTBOUND X-BESS-BRTS-Status: 1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Robert, On 04/05/18 11:26, Robert Richter wrote: > On 04.05.18 10:54:32, Matt Redfearn wrote: >> perf is available for MIPS and supports many more CPU types than oprofile. >> oprofile userspace seemingly has been broken since 1.0.0 - removing oprofile >> support from the MIPS kernel would not break it more thatn it already is, > > What do you mean with "oprofile is broken"? It looks like you modified > Kconfig to enable oprofile and perf in parallel, which is not intended > to work. Have you tried a kernel with oprofile disabled and perf > enabled? Oh I see what you mean - previously I was trying v1.1.0 of the userspace with a kernel that has perf disabled - and that did not work (I assumed, naively, that the kernel oprofile code was required to run the oprofile userspace). Thanks for the pointer - I confirmed that oprofile 1.1.0 userspace tools work with a kernel with "CONFIG_OPROFILE is not set", and "CONFIG_HW_PERF_EVENTS=y". > > As said, oprofile version 0.9.x is still available for cpus that do > not support perf. What is the breakage? The breakage I originally set out to fix was the MT support in perf. https://www.linux-mips.org/archives/linux-mips/2018-04/msg00259.html Since the perf code shares so much copied code from oprofile, those same issues exist in oprofile and ought to be addressed. But as newer oprofile userspace does not use the (MIPS) kernel oprofile code, then we could, perhaps, just remove it (as per the RFC). That would break legacy tools (0.9.x) though... Thanks, Matt > > Thanks, > > -Robert >