From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752705AbdKFJXO (ORCPT ); Mon, 6 Nov 2017 04:23:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56138 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751237AbdKFJXK (ORCPT ); Mon, 6 Nov 2017 04:23:10 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 89AF8C049D49 Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=jolsa@redhat.com Date: Mon, 6 Nov 2017 10:23:05 +0100 From: Jiri Olsa To: Milind Chabbi Cc: peterz@infradead.org, mingo@redhat.com, acme@kernel.org, alexander.shishkin@linux.intel.com, namhyung@kernel.org, linux-kernel@vger.kernel.org, mtk.manpages@gmail.com, linux-man@vger.kernel.org, mpe@ellerman.id.au, ak@linux.intel.com, kan.liang@intel.com, hbathini@linux.vnet.ibm.com, sukadev@linux.vnet.ibm.com, yao.jin@linux.intel.com Subject: Re: [PATCH] perf/core: fast breakpoint modification via _IOC_MODIFY_BREAKPOINT Message-ID: <20171106092305.GA16382@krava> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.1 (2017-09-22) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Mon, 06 Nov 2017 09:23:10 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Nov 05, 2017 at 02:35:34PM -0800, Milind Chabbi wrote: SNIP > +static int _perf_event_modify_breakpoint(struct perf_event *bp, > + struct perf_event_attr *attr) > +{ > + u64 old_addr = bp->attr.bp_addr; > + u64 old_len = bp->attr.bp_len; > + int old_type = bp->attr.bp_type; > + int err = 0; > + > + _perf_event_disable(bp); > + > + bp->attr.bp_addr = attr->bp_addr; > + bp->attr.bp_type = attr->bp_type; > + bp->attr.bp_len = attr->bp_len; > + > + if (attr->disabled) > + goto end; > + > + err = validate_hw_breakpoint(bp); thre patch is mangled.. seems like you've lost all your tabs somehow anyway, should you also do the release_bp_slot/reserve_bp_slot magic to keep the slot accounting corrent? jirka