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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9A0EC433EF for ; Tue, 12 Oct 2021 05:51:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9ACDD60EB6 for ; Tue, 12 Oct 2021 05:51:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232793AbhJLFxT (ORCPT ); Tue, 12 Oct 2021 01:53:19 -0400 Received: from out30-132.freemail.mail.aliyun.com ([115.124.30.132]:55965 "EHLO out30-132.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232673AbhJLFxQ (ORCPT ); Tue, 12 Oct 2021 01:53:16 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R931e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04395;MF=yun.wang@linux.alibaba.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_---0UrXy.sr_1634017873; Received: from testdeMacBook-Pro.local(mailfrom:yun.wang@linux.alibaba.com fp:SMTPD_---0UrXy.sr_1634017873) by smtp.aliyun-inc.com(127.0.0.1); Tue, 12 Oct 2021 13:51:14 +0800 Subject: Re: [RESEND PATCH v2] trace: prevent preemption in perf_ftrace_function_call() To: Peter Zijlstra Cc: Steven Rostedt , Ingo Molnar , open list , Jiri Olsa References: <20211008200328.5b88422d@oasis.local.home> <87aeef5b-c457-d4df-8abf-f9f035d73dbc@linux.alibaba.com> <20211011144510.GE174703@worktop.programming.kicks-ass.net> From: =?UTF-8?B?546L6LSH?= Message-ID: Date: Tue, 12 Oct 2021 13:51:13 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: <20211011144510.GE174703@worktop.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/10/11 下午10:45, Peter Zijlstra wrote: [snip] >>> >>> Oh, I might've gotten that wrong, I assumed regular trylock semantics, >>> but it doesn't look like that's right. >> >> I will use bit instead ret and give some testing :-) >> >> BTW, would you prefer to merge these changes into this patch or maybe send >> another patch with your suggested-by? > > Yeah, please send another patch; once you've confirmed it actually works > etc.. I did this before waking (as evidence per the above), who knows > what else I did wrong :-) I've send the: [PATCH 0/2] ftrace: make sure preemption disabled on recursion testing should have taking care all the places, but only testing with x86 since I got no machine for other arch... just by logically it should be fine. Regards, Michael Wang >