From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754946Ab3CONoi (ORCPT ); Fri, 15 Mar 2013 09:44:38 -0400 Received: from multi.imgtec.com ([194.200.65.239]:34611 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754397Ab3CONog (ORCPT ); Fri, 15 Mar 2013 09:44:36 -0400 From: James Hogan To: CC: James Hogan , Peter Zijlstra , Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo Subject: [PATCH 7/9] metag: perf: don't reset TXTACTCYC Date: Fri, 15 Mar 2013 13:43:46 +0000 Message-ID: <1363355028-23278-8-git-send-email-james.hogan@imgtec.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1363355028-23278-1-git-send-email-james.hogan@imgtec.com> References: <1363355028-23278-1-git-send-email-james.hogan@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain X-SEF-Processed: 7_3_0_01181__2013_03_15_13_44_35 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The thread active cycle counter TXTACTCYC is used in __delay so it shouldn't really be reset to zero by perf. Fix perf to just read the value, and instead of clearing it, record the prev_count value in enable_counter so that the delta calculations know about the previous value. Signed-off-by: James Hogan Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo --- arch/metag/kernel/perf/perf_event.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/arch/metag/kernel/perf/perf_event.c b/arch/metag/kernel/perf/perf_event.c index 54fde35..a1eff36 100644 --- a/arch/metag/kernel/perf/perf_event.c +++ b/arch/metag/kernel/perf/perf_event.c @@ -617,9 +617,7 @@ static void metag_pmu_enable_counter(struct hw_perf_event *event, int idx) WARN_ONCE((config != 0x100), "invalid configuration (%d) for counter (%d)\n", config, idx); - - /* Reset the cycle count */ - __core_reg_set(TXTACTCYC, 0); + local64_set(&event->prev_count, __core_reg_get(TXTACTCYC)); goto unlock; } @@ -708,9 +706,8 @@ static u64 metag_pmu_read_counter(int idx) { u32 tmp = 0; - /* The act of reading the cycle counter also clears it */ if (METAG_INST_COUNTER == idx) { - __core_reg_swap(TXTACTCYC, tmp); + tmp = __core_reg_get(TXTACTCYC); goto out; } -- 1.8.1.2