Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759463Ab2JSQbQ (ORCPT ); Fri, 19 Oct 2012 12:31:16 -0400 Received: from mail-la0-f46.google.com ([209.85.215.46]:44630 "EHLO mail-la0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752115Ab2JSQbO (ORCPT ); Fri, 19 Oct 2012 12:31:14 -0400 MIME-Version: 1.0 In-Reply-To: <1350664077.2768.32.camel@twins> References: <1350658326-14715-1-git-send-email-eranian@google.com> <1350658326-14715-3-git-send-email-eranian@google.com> <1350664077.2768.32.camel@twins> Date: Fri, 19 Oct 2012 18:31:12 +0200 Message-ID: Subject: Re: [PATCH 2/2] perf: SNB exclusive PMU access for INST_RETIRED:PREC_DIST From: Stephane Eranian To: Peter Zijlstra Cc: LKML , "mingo@elte.hu" , "ak@linux.intel.com" , Arnaldo Carvalho de Melo , Jiri Olsa Content-Type: text/plain; charset=UTF-8 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1023 Lines: 22 On Fri, Oct 19, 2012 at 6:27 PM, Peter Zijlstra wrote: > On Fri, 2012-10-19 at 16:52 +0200, Stephane Eranian wrote: >> +static int intel_pebs_aliases_snb(struct perf_event *event) >> +{ >> + u64 cfg = event->hw.config; >> + /* >> + * for INST_RETIRED.PREC_DIST to work correctly with PEBS, it must >> + * be measured alone on SNB (exclusive PMU access) as per Intel SDM. >> + */ >> + if ((cfg & INTEL_ARCH_EVENT_MASK) == 0x01c0 && !event->attr.exclusive) { >> + pr_info("perf: INST_RETIRED.PREC_DIST only works in exclusive mode\n"); >> + return -EINVAL; > > This isn't limited to admin, right? So the above turns into a DoS on the > console. > Ok, so how about a WARN_ON_ONCE() instead? -- 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/