Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752906AbaJVO7J (ORCPT ); Wed, 22 Oct 2014 10:59:09 -0400 Received: from mx1.redhat.com ([209.132.183.28]:10322 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751945AbaJVO7I (ORCPT ); Wed, 22 Oct 2014 10:59:08 -0400 Date: Wed, 22 Oct 2014 16:58:04 +0200 From: Jiri Olsa To: Stephane Eranian Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@elte.hu, ak@linux.intel.com, kan.liang@intel.com, bp@alien8.de, maria.n.dimakopoulou@gmail.com Subject: Re: [PATCH v2 11/12] perf/x86: make HT bug workaround conditioned on HT enabled Message-ID: <20141022145804.GC15126@krava.brq.redhat.com> References: <1412872486-2930-1-git-send-email-eranian@google.com> <1412872486-2930-12-git-send-email-eranian@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1412872486-2930-12-git-send-email-eranian@google.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 09, 2014 at 06:34:45PM +0200, Stephane Eranian wrote: SNIP > --- a/arch/x86/kernel/cpu/perf_event_intel.c > +++ b/arch/x86/kernel/cpu/perf_event_intel.c > @@ -12,6 +12,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -1811,7 +1812,7 @@ intel_start_scheduling(struct cpu_hw_events *cpuc) > /* > * nothing needed if in group validation mode > */ > - if (cpuc->is_fake) > + if (cpuc->is_fake || !is_ht_workaround_enabled()) > return; > /* > * no exclusion needed > @@ -1849,8 +1850,9 @@ intel_stop_scheduling(struct cpu_hw_events *cpuc) > /* > * nothing needed if in group validation mode > */ > - if (cpuc->is_fake) > + if (cpuc->is_fake || !is_ht_workaround_enabled()) > return; Is it possible to change is_ht_workaround_enabled() result within intel_start_scheduling and intel_stop_scheduling time frame? like following would happen: is_ht_workaround_enabled == 1 intel_start_scheduling -> spin_lock(&excl_cntrs->lock); # echo 0 > /sys/devices/cpu/ht_bug_workaround is_ht_workaround_enabled == 0 intel_stop_scheduling -> wont call spin_unlock(&excl_cntrs->lock) for some reason I can't get HT enabled on my HSW server, so I cannot try ;-) jirka -- 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/