From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Michael Ellerman To: Subject: [PATCH 5/9] powerpc/perf: Don't enable if we have zero events Date: Fri, 28 Jun 2013 18:15:14 +1000 Message-Id: <1372407319-718-5-git-send-email-michael@ellerman.id.au> In-Reply-To: <1372407319-718-1-git-send-email-michael@ellerman.id.au> References: <1372407319-718-1-git-send-email-michael@ellerman.id.au> Cc: sukadev@linux.vnet.ibm.com, Paul Mackerras , khandual@linux.vnet.ibm.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , In power_pmu_enable() we still enable the PMU even if we have zero events. This should have no effect but doesn't make much sense. Instead just return after telling the hypervisor that we are not using the PMCs. Signed-off-by: Michael Ellerman --- arch/powerpc/perf/core-book3s.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index af4b4b1..d3ee2e5 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -926,6 +926,11 @@ static void power_pmu_enable(struct pmu *pmu) if (!cpuhw->disabled) goto out; + if (cpuhw->n_events == 0) { + ppc_set_pmu_inuse(0); + goto out; + } + cpuhw->disabled = 0; /* @@ -937,8 +942,6 @@ static void power_pmu_enable(struct pmu *pmu) if (!cpuhw->n_added) { mtspr(SPRN_MMCRA, cpuhw->mmcr[2] & ~MMCRA_SAMPLE_ENABLE); mtspr(SPRN_MMCR1, cpuhw->mmcr[1]); - if (cpuhw->n_events == 0) - ppc_set_pmu_inuse(0); goto out_enable; } -- 1.7.10.4