Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933398Ab2JXIXV (ORCPT ); Wed, 24 Oct 2012 04:23:21 -0400 Received: from mga09.intel.com ([134.134.136.24]:27325 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755607Ab2JXIXT (ORCPT ); Wed, 24 Oct 2012 04:23:19 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.80,639,1344236400"; d="scan'208";a="231525604" Message-ID: <5087A574.3040507@intel.com> Date: Wed, 24 Oct 2012 16:23:16 +0800 From: "Yan, Zheng" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121016 Thunderbird/16.0.1 MIME-Version: 1.0 To: Stephane Eranian CC: LKML , Peter Zijlstra , "ak@linux.intel.com" Subject: Re: [PATCH V2 1/7] perf, x86: Reduce lbr_sel_map size References: <1351058350-9159-1-git-send-email-zheng.z.yan@intel.com> <1351058350-9159-2-git-send-email-zheng.z.yan@intel.com> <50879D71.3080108@intel.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2302 Lines: 60 On 10/24/2012 04:15 PM, Stephane Eranian wrote: > On Wed, Oct 24, 2012 at 9:49 AM, Yan, Zheng wrote: >> On 10/24/2012 03:28 PM, Stephane Eranian wrote: >>> On Wed, Oct 24, 2012 at 7:59 AM, Yan, Zheng wrote: >>>> From: "Yan, Zheng" >>>> >>>> The index of lbr_sel_map is bit value of perf branch_sample_type. >>>> By using bit shift as index, we can reduce lbr_sel_map size. >>>> >>>> Signed-off-by: Yan, Zheng >>>> --- >>>> arch/x86/kernel/cpu/perf_event.h | 4 +++ >>>> arch/x86/kernel/cpu/perf_event_intel_lbr.c | 50 ++++++++++++++---------------- >>>> include/uapi/linux/perf_event.h | 42 +++++++++++++++++-------- >>>> 3 files changed, 56 insertions(+), 40 deletions(-) >>>> >>>> diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h >>>> index d3b3bb7..ea6749a 100644 >>>> --- a/arch/x86/kernel/cpu/perf_event.h >>>> +++ b/arch/x86/kernel/cpu/perf_event.h >>>> @@ -412,6 +412,10 @@ struct x86_pmu { >>>> struct perf_guest_switch_msr *(*guest_get_msrs)(int *nr); >>>> }; >>>> >>>> +enum { >>>> + PERF_SAMPLE_BRANCH_SELECT_MAP_SIZE = PERF_SAMPLE_BRANCH_MAX_SHIFT, >>>> +}; >>>> + >>> What's the point on the extraneous definition? >> >> because later patches will add map PERF_SAMPLE_BRANCH_CALL_STACK, it will make >> "PERF_SAMPLE_BRANCH_SELECT_MAP_SIZE != PERF_SAMPLE_BRANCH_MAX_SHIFT" >> > And you are not going to do: > > enum perf_branch_sample_type_shift { > ... > PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT = 10 > PERF_SAMPLE_BRANCH_MAX_SHIFT > }; > > PERF_SAMPLE_BRANCH_CALL_STACK = 1 << PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT > > Unless you're telling you are not going to add a mapping for > PERF_SAMPLE_CALL_STACK to the > lbr_sel_map[]? > I think include/uapi/linux/perf_event.h should only contain definition for user API. So I added PERF_SAMPLE_BRANCH_CALL_STACK_SHIFT and PERF_SAMPLE_BRANCH_CALL_STACK to arch/x86/kernel/cpu/perf_event.h. Please check patch 1. Regards Yan, Zheng -- 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/