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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 13136C4646D for ; Mon, 6 Aug 2018 14:21:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CA61F21A3B for ; Mon, 6 Aug 2018 14:21:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CA61F21A3B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 S1731978AbeHFQbO (ORCPT ); Mon, 6 Aug 2018 12:31:14 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:48332 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727451AbeHFQbO (ORCPT ); Mon, 6 Aug 2018 12:31:14 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A42A740201A0; Mon, 6 Aug 2018 14:21:53 +0000 (UTC) Received: from krava (unknown [10.43.17.214]) by smtp.corp.redhat.com (Postfix) with SMTP id AFED61C4E7; Mon, 6 Aug 2018 14:21:49 +0000 (UTC) Date: Mon, 6 Aug 2018 16:21:49 +0200 From: Jiri Olsa To: Oleg Nesterov Cc: Jiri Olsa , Arnaldo Carvalho de Melo , Milind Chabbi , lkml , Ingo Molnar , Namhyung Kim , David Ahern , Alexander Shishkin , Peter Zijlstra , Frederic Weisbecker Subject: Re: [PATCH 2/2] perf/hw_breakpoint: Modify breakpoint even if the new attr has disabled set Message-ID: <20180806142149.GA16446@krava> References: <20180806101241.6444-1-jolsa@kernel.org> <20180806101241.6444-3-jolsa@kernel.org> <20180806124839.GC7840@redhat.com> <20180806130730.GD7840@redhat.com> <20180806133747.GB7463@krava> <20180806134946.GF7840@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180806134946.GF7840@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Mon, 06 Aug 2018 14:21:53 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Mon, 06 Aug 2018 14:21:53 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'jolsa@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 06, 2018 at 03:49:47PM +0200, Oleg Nesterov wrote: > On 08/06, Jiri Olsa wrote: > > > > On Mon, Aug 06, 2018 at 03:07:31PM +0200, Oleg Nesterov wrote: > > > On 08/06, Oleg Nesterov wrote: > > > > > > > > But, with or without this fix, shouldn't we set .disabled = 1 if modify_() fails? > > > > IIUC this doesn't matter, bp->attr.disabled is not really used anyway, but looks a > > > > bit confusing. > > > > > > I am looking at another caller perf_event_modify_breakpoint(). It too doesn't set > > > attr.disabled = 1 on failure, it does _perf_event_enable() instead so attr.disabled > > > should be correct. > > > > > > But this looks wrong. If modify_user_hw_breakpoint_check() paths fails after > > > arch_validate_hwbkpt_settings() was called, then we can not simply restore > > > > hum, arch_validate_hwbkpt_settings was removed recently.. r u checking the last sources? > > I do not see this change in Linus's tree... > > > Nevermind, if this was already changed/fixed somewhere, please forget. should be in tip tree, all around this commit: cffbb3bd444b perf/hw_breakpoint: Remove default hw_breakpoint_arch_parse() jirka