From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id A1A7F1A1052 for ; Wed, 10 Jun 2015 22:11:30 +1000 (AEST) Received: from e23smtp08.au.ibm.com (e23smtp08.au.ibm.com [202.81.31.141]) (using TLSv1 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 751DE14028F for ; Wed, 10 Jun 2015 22:11:30 +1000 (AEST) Received: from /spool/local by e23smtp08.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 10 Jun 2015 22:11:29 +1000 Received: from d23relay07.au.ibm.com (d23relay07.au.ibm.com [9.190.26.37]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id D115A2BB0040 for ; Wed, 10 Jun 2015 22:11:26 +1000 (EST) Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay07.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t5ACBIGk58523878 for ; Wed, 10 Jun 2015 22:11:27 +1000 Received: from d23av04.au.ibm.com (localhost [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t5ACArPp027082 for ; Wed, 10 Jun 2015 22:10:54 +1000 Message-ID: <5578293B.9060506@linux.vnet.ibm.com> Date: Wed, 10 Jun 2015 17:40:35 +0530 From: Anshuman Khandual MIME-Version: 1.0 To: Daniel Axtens CC: linuxppc-dev@ozlabs.org, mikey@neuling.org, sukadev@linux.vnet.ibm.com Subject: Re: [PATCH V8 08/10] powerpc, perf: Change POWER8 PMU configuration to work with SW filters References: <1433763511-5270-1-git-send-email-khandual@linux.vnet.ibm.com> <1433763511-5270-8-git-send-email-khandual@linux.vnet.ibm.com> <1433915365.3096.44.camel@axtens.net> In-Reply-To: <1433915365.3096.44.camel@axtens.net> Content-Type: text/plain; charset=utf-8 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 06/10/2015 11:19 AM, Daniel Axtens wrote: > On Mon, 2015-06-08 at 17:08 +0530, Anshuman Khandual wrote: >> > The kernel now supports SW based branch filters for book3s systems with >> > some specific requirements while dealing with HW supported branch filters >> > in order to achieve overall OR semantics prevailing in perf branch stack >> > sampling framework. This patch adapts the BHRB branch filter configuration >> > to meet those protocols. POWER8 PMU can only handle one HW based branch >> > filter request at any point of time. For all other combinations PMU will >> > pass it on to the SW. >> > >> > Signed-off-by: Anshuman Khandual >> > --- >> > arch/powerpc/perf/power8-pmu.c | 51 ++++++++++++++++++++++++++++++++++++------ >> > 1 file changed, 44 insertions(+), 7 deletions(-) >> > >> > diff --git a/arch/powerpc/perf/power8-pmu.c b/arch/powerpc/perf/power8-pmu.c >> > index 5e17cb5..8fccf6c 100644 >> > --- a/arch/powerpc/perf/power8-pmu.c >> > +++ b/arch/powerpc/perf/power8-pmu.c >> > @@ -656,6 +656,16 @@ static int power8_generic_events[] = { >> > > This is, I think, the third time you've modified this function in this > patch series. I appreciate the fact that you're trying to keep logical > changes separate, but it seems to me like this change might be able to > be combined with patch 4, and given a single commit message that clearly > explains the complete scope of the changes. Here I have to disagree with you. The changes in this patch like PMU should not handle multiple filter requests as it does not support the OR semantic required in the protocol, the fact that we need to pass on the entire branch filtering responsibility to the SW comes into picture after we have enabled the SW branch filtering support in the previous patch. So these changes have to follow that up logically and sequentially in that order.