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 C0610C4646D for ; Mon, 6 Aug 2018 13:37:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 80FDA21990 for ; Mon, 6 Aug 2018 13:37:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 80FDA21990 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 S1730304AbeHFPq7 (ORCPT ); Mon, 6 Aug 2018 11:46:59 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:56150 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727582AbeHFPq7 (ORCPT ); Mon, 6 Aug 2018 11:46:59 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 20D127C6A9; Mon, 6 Aug 2018 13:37:50 +0000 (UTC) Received: from krava (unknown [10.43.17.214]) by smtp.corp.redhat.com (Postfix) with SMTP id 58CEA2166BA0; Mon, 6 Aug 2018 13:37:48 +0000 (UTC) Date: Mon, 6 Aug 2018 15:37:47 +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: <20180806133747.GB7463@krava> References: <20180806101241.6444-1-jolsa@kernel.org> <20180806101241.6444-3-jolsa@kernel.org> <20180806124839.GC7840@redhat.com> <20180806130730.GD7840@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180806130730.GD7840@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Mon, 06 Aug 2018 13:37:50 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Mon, 06 Aug 2018 13:37:50 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.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 03:07:31PM +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? jirka