Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755169AbaBTSXO (ORCPT ); Thu, 20 Feb 2014 13:23:14 -0500 Received: from merlin.infradead.org ([205.233.59.134]:42363 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753634AbaBTSXI (ORCPT ); Thu, 20 Feb 2014 13:23:08 -0500 Date: Thu, 20 Feb 2014 19:23:00 +0100 From: Peter Zijlstra To: Vince Weaver Cc: Dave Jones , Linux Kernel , Ingo Molnar , Paul Mackerras , Steven Rostedt Subject: Re: x86_pmu_start WARN_ON. Message-ID: <20140220182300.GN9987@twins.programming.kicks-ass.net> References: <20140217152859.GF15586@twins.programming.kicks-ass.net> <20140219101949.GG15586@twins.programming.kicks-ass.net> <20140220100830.GN6835@laptop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 20, 2014 at 01:03:16PM -0500, Vince Weaver wrote: > attached, it's not very big. This is I think the relevant bit: pec_1076_warn-2804 [000] d... 147.926153: x86_pmu_disable: x86_pmu_disable pec_1076_warn-2804 [000] d... 147.926153: x86_pmu_state: Events: { pec_1076_warn-2804 [000] d... 147.926156: x86_pmu_state: 0: state: .R config: ffffffffffffffff ( (null)) pec_1076_warn-2804 [000] d... 147.926158: x86_pmu_state: 33: state: AR config: 0 (ffff88011ac99800) pec_1076_warn-2804 [000] d... 147.926159: x86_pmu_state: } pec_1076_warn-2804 [000] d... 147.926160: x86_pmu_state: n_events: 1, n_added: 0, n_txn: 1 pec_1076_warn-2804 [000] d... 147.926161: x86_pmu_state: Assignment: { pec_1076_warn-2804 [000] d... 147.926162: x86_pmu_state: 0->33 tag: 1 config: 0 (ffff88011ac99800) pec_1076_warn-2804 [000] d... 147.926163: x86_pmu_state: } pec_1076_warn-2804 [000] d... 147.926166: collect_events: Adding event: 1 (ffff880119ec8800) pec_1076_warn-2804 [000] d... 147.926170: collect_events: Adding event: 0 (ffff8800c9e01800) pec_1076_warn-2804 [000] d... 147.926172: collect_events: Adding event: 4 (ffff8800cbab2c00) pec_1076_warn-2804 [000] d... 147.926177: x86_pmu_enable: x86_pmu_enable pec_1076_warn-2804 [000] d... 147.926177: x86_pmu_state: Events: { pec_1076_warn-2804 [000] d... 147.926179: x86_pmu_state: 0: state: .R config: ffffffffffffffff ( (null)) pec_1076_warn-2804 [000] d... 147.926181: x86_pmu_state: 33: state: AR config: 0 (ffff88011ac99800) pec_1076_warn-2804 [000] d... 147.926182: x86_pmu_state: } pec_1076_warn-2804 [000] d... 147.926184: x86_pmu_state: n_events: 2, n_added: 2, n_txn: 2 pec_1076_warn-2804 [000] d... 147.926184: x86_pmu_state: Assignment: { pec_1076_warn-2804 [000] d... 147.926186: x86_pmu_state: 0->33 tag: 1 config: 0 (ffff88011ac99800) pec_1076_warn-2804 [000] d... 147.926188: x86_pmu_state: 1->0 tag: 1 config: 1 (ffff880119ec8800) pec_1076_warn-2804 [000] d... 147.926188: x86_pmu_state: } pec_1076_warn-2804 [000] d... 147.926190: x86_pmu_enable: S0: hwc->idx: 33, hwc->last_cpu: 0, hwc->last_tag: 1 hwc->state: 0 pec_1076_warn-2804 [000] d... 147.926191: x86_pmu_enable: starting: 0 so it does indeed look like n_added got scrambled; we started out with 1 event on disable; we've got 2 events on enable, but n_added is also 2, which would suggest we had 0 on disable. That makes us want to (re)start the NMI counter alright. I've got to go run errands for a bit; hopefully I can find a bit of time later tonight to look this over. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/