Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755387AbbGQR6Y (ORCPT ); Fri, 17 Jul 2015 13:58:24 -0400 Received: from mail-la0-f46.google.com ([209.85.215.46]:33790 "EHLO mail-la0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753448AbbGQR6X (ORCPT ); Fri, 17 Jul 2015 13:58:23 -0400 MIME-Version: 1.0 In-Reply-To: <37D7C6CF3E00A74B8858931C1DB2F0770188E022@SHSMSX103.ccr.corp.intel.com> References: <1437078831-10152-1-git-send-email-kan.liang@intel.com> <1437078831-10152-3-git-send-email-kan.liang@intel.com> <20150717121141.GC26091@leverpostej> <20150717134629.GN25159@twins.programming.kicks-ass.net> <20150717135106.GC18673@twins.programming.kicks-ass.net> <37D7C6CF3E00A74B8858931C1DB2F0770188DDB9@SHSMSX103.ccr.corp.intel.com> <37D7C6CF3E00A74B8858931C1DB2F0770188E022@SHSMSX103.ccr.corp.intel.com> From: Andy Lutomirski Date: Fri, 17 Jul 2015 10:58:02 -0700 Message-ID: Subject: Re: [PATCH 2/9] perf/x86: core_misc PMU disable and enable support To: "Liang, Kan" Cc: Peter Zijlstra , Mark Rutland , "mingo@redhat.com" , "acme@kernel.org" , "eranian@google.com" , "ak@linux.intel.com" , "Hunter, Adrian" , "dsahern@gmail.com" , "jolsa@kernel.org" , "namhyung@kernel.org" , "linux-kernel@vger.kernel.org" , "luto@kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3260 Lines: 83 On Fri, Jul 17, 2015 at 10:52 AM, Liang, Kan wrote: > > >> >> On Fri, Jul 17, 2015 at 8:35 AM, Liang, Kan wrote: >> > >> > >> >> On Fri, Jul 17, 2015 at 03:46:29PM +0200, Peter Zijlstra wrote: >> >> > On Fri, Jul 17, 2015 at 01:11:41PM +0100, Mark Rutland wrote: >> >> > > > diff --git a/arch/x86/kernel/cpu/perf_event_intel.c >> >> > > > b/arch/x86/kernel/cpu/perf_event_intel.c >> >> > > > index b9826a9..651a86d 100644 >> >> > > > --- a/arch/x86/kernel/cpu/perf_event_intel.c >> >> > > > +++ b/arch/x86/kernel/cpu/perf_event_intel.c >> >> > > > @@ -1586,6 +1586,8 @@ static int intel_pmu_handle_irq(struct >> >> pt_regs *regs) >> >> > > > if (!x86_pmu.late_ack) >> >> > > > apic_write(APIC_LVTPC, APIC_DM_NMI); >> >> > > > __intel_pmu_disable_all(); >> >> > > > + if (cpuc->core_misc_active_mask) >> >> > > > + intel_core_misc_pmu_disable(); >> >> > > >> >> > > Huh? Free running counters have nothing to do with the PMU >> >> > > interrupt; there's nothing they can do to trigger it. This feels very >> hacky. >> >> > > >> >> > > If this is necessary, surely it should live in __intel_pmu_disable_all? >> >> > > >> >> > > [...] >> >> > >> >> > Yeah this is crazy. It should not live in the regular PMU at all, >> >> > not be Intel specific. >> >> >> >> >> lkml.kernel.org/r/2c37309d20afadf88ad4a82cf0ce02b9152801e2.143025615 >> >> 4.git.luto@kernel.org >> >> >> >> That does the right thing for free running MSRs. >> >> >> >> Take it and expand. >> > >> > The first patch did the similar thing as the link you shared with. >> > Here is the first patch. >> > https://lkml.org/lkml/2015/7/16/953 >> > >> > This patch is expend the per-core core_misc PMU based on the first >> patch. >> > I implemented this patch is because that one of the biggest concern >> > from upstream for mix PMU group is that it breaks group semantics. >> > When one PMU is stop, the other PMU is still running. >> > So I introduce the enable/disable function. Other PMUs can discard the >> > counter value for core_misc event when they are stop or in irq. >> > >> > If you think it should not live in the regular PMU, I can just remove the >> codes. >> > We just keep core_misc event running and no harm in it. >> >> I know very little about perf pmu organization, but I think that AMD >> supports APERF and MPERF, too, so it may make sense to have that thing >> live outside a file with "intel" in the name. >> >> Also, should the driver detect those using the cpuid bit? >> > > Hi Andy, > > Yes, it detects the cpuid to determine which counters are available. > If we want to implement a common file for both Intel and AMD, > we can also check cupid.06h.ecx[bit 0] for a/mperf availability on Intel > platform. > > Do you have a V2 patch already? I'm asking is because you once > mentioned it... :) No, and I also don't have PPERF hardware, etc, so there's not really much I can do. Feel free to do whatever you like with my v1. --Andy -- 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/