From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752784Ab3EFLhD (ORCPT ); Mon, 6 May 2013 07:37:03 -0400 Received: from e23smtp07.au.ibm.com ([202.81.31.140]:59152 "EHLO e23smtp07.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752470Ab3EFLhB (ORCPT ); Mon, 6 May 2013 07:37:01 -0400 From: Anshuman Khandual To: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org Cc: michael@ellerman.id.au, mikey@neuling.org, benh@kernel.crashing.org Subject: [PATCH] powerpc, perf: Clear out branch entries to avoid any previous stale values Date: Mon, 6 May 2013 13:34:40 +0530 Message-Id: <1367827480-5375-1-git-send-email-khandual@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.11.7 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13050611-0260-0000-0000-000002ED6A4B Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The 'to' field inside branch entries might contain stale values from previous PMU interrupt instances which had indirect branches. So clear all the values before reading a fresh set of BHRB entries after a PMU interrupt. Signed-off-by: Anshuman Khandual --- arch/powerpc/perf/core-book3s.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index c627843..09db68d 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -1590,6 +1590,8 @@ static void record_and_restart(struct perf_event *event, unsigned long val, if (event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK) { struct cpu_hw_events *cpuhw; cpuhw = &__get_cpu_var(cpu_hw_events); + memset(cpuhw->bhrb_entries, 0, + sizeof(struct perf_branch_entry) * BHRB_MAX_ENTRIES); power_pmu_bhrb_read(cpuhw); data.br_stack = &cpuhw->bhrb_stack; } -- 1.7.11.7