From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752039Ab3LRAIL (ORCPT ); Tue, 17 Dec 2013 19:08:11 -0500 Received: from ozlabs.org ([203.10.76.45]:60303 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750950Ab3LRAIJ (ORCPT ); Tue, 17 Dec 2013 19:08:09 -0500 Message-ID: <1387325285.19507.1.camel@concordia> Subject: Re: [PATCH V4 09/10] power8, perf: Change BHRB branch filter configuration From: Michael Ellerman To: Anshuman Khandual Cc: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, mikey@neuling.org, ak@linux.intel.com, eranian@google.com, acme@ghostprotocols.net, sukadev@linux.vnet.ibm.com, mingo@kernel.org Date: Wed, 18 Dec 2013 11:08:05 +1100 In-Reply-To: <52AAC356.1000308@linux.vnet.ibm.com> References: <20131209062147.51F822C00C5@ozlabs.org> <52AAC356.1000308@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.8.4-0ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2013-12-13 at 13:50 +0530, Anshuman Khandual wrote: > On 12/09/2013 11:51 AM, Michael Ellerman wrote: > > > > As I said in my comments on version 3 which you ignored: > > > > I think it would be clearer if we actually checked for the possibilities we > > allow and let everything else fall through, eg: > > > > Â Â Â Â Â Â Â Â /* Ignore user/kernel/hv bits */ > > Â Â Â Â Â Â Â Â branch_sample_type &= ~PERF_SAMPLE_BRANCH_PLM_ALL; > > > > Â Â Â Â Â Â Â Â if (branch_sample_type == PERF_SAMPLE_BRANCH_ANY) > > Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â return 0; > > > > Â Â Â Â Â Â Â Â if (branch_sample_type == PERF_SAMPLE_BRANCH_ANY_CALL) > > Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â return POWER8_MMCRA_IFM1; > > Â > > Â Â Â Â Â Â Â Â if (branch_sample_type == PERF_SAMPLE_BRANCH_COND) > > Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â return POWER8_MMCRA_IFM3; > > Â Â Â Â Â Â Â Â > > Â Â Â Â Â Â Â Â return -1; > > > > Hey Michael, > > This patch only adds support for the PERF_SAMPLE_BRANCH_COND filter, if the > over all code flow does not clearly suggest that all combinations of any of > these HW filters are invalid, then we can go with one more patch to clean > that up before or after this patch but not here in this patch. Finally the > code section here will look something like this. Does it sound good ? Better, but not quite. > static u64 power8_bhrb_filter_map(u64 branch_sample_type) > { > u64 pmu_bhrb_filter = 0; > > /* BHRB and regular PMU events share the same privilege state > * filter configuration. BHRB is always recorded along with a > * regular PMU event. As the privilege state filter is handled > * in the basic PMC configuration of the accompanying regular > * PMU event, we ignore any separate BHRB specific request. > */ > > /* Ignore user, kernel, hv bits */ > branch_sample_type &= ~PERF_SAMPLE_BRANCH_PLM_ALL; > > if (branch_sample_type == PERF_SAMPLE_BRANCH_ANY) > return pmu_bhrb_filter; return 0; > > > if (branch_sample_type == PERF_SAMPLE_BRANCH_ANY_CALL) { > pmu_bhrb_filter |= POWER8_MMCRA_IFM1; > return pmu_bhrb_filter; return POWER8_MMCRA_IFM1; > } > > if (branch_sample_type == PERF_SAMPLE_BRANCH_COND) { > pmu_bhrb_filter |= POWER8_MMCRA_IFM3; > return pmu_bhrb_filter; return POWER8_MMCRA_IFM3; > } > > /* Every thing else is unsupported */ > return -1; > } cheers