Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755117AbaF3IvV (ORCPT ); Mon, 30 Jun 2014 04:51:21 -0400 Received: from mga02.intel.com ([134.134.136.20]:53402 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755005AbaF3IvN (ORCPT ); Mon, 30 Jun 2014 04:51:13 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,573,1400050800"; d="scan'208";a="536451004" From: "Yan, Zheng" To: linux-kernel@vger.kernel.org Cc: a.p.zijlstra@chello.nl, mingo@kernel.org, acme@infradead.org, eranian@google.com, andi@firstfloor.org, "Yan, Zheng" Subject: [PATCH V4 07/16] perf, x86: track number of events that use LBR callstack Date: Mon, 30 Jun 2014 16:50:44 +0800 Message-Id: <1404118253-19532-8-git-send-email-zheng.z.yan@intel.com> X-Mailer: git-send-email 1.9.0 In-Reply-To: <1404118253-19532-1-git-send-email-zheng.z.yan@intel.com> References: <1404118253-19532-1-git-send-email-zheng.z.yan@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When enabling/disabling an event, check if the event uses the LBR callstack feature, adjust the LBR callstack usage count accordingly. Later patch will use the usage count to decide if LBR stack should be saved/restored. Signed-off-by: Yan, Zheng --- arch/x86/kernel/cpu/perf_event_intel_lbr.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c index 9a94fff..66969cb 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c +++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c @@ -198,9 +198,15 @@ void intel_pmu_lbr_sched_task(struct perf_event_context *ctx, bool sched_in) } } +static inline bool branch_user_callstack(unsigned br_sel) +{ + return (br_sel & X86_BR_USER) && (br_sel & X86_BR_CALL_STACK); +} + void intel_pmu_lbr_enable(struct perf_event *event) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct x86_perf_task_context *task_ctx; if (!x86_pmu.lbr_nr) return; @@ -214,6 +220,10 @@ void intel_pmu_lbr_enable(struct perf_event *event) } cpuc->br_sel = event->hw.branch_reg.reg; + task_ctx = event->ctx ? event->ctx->task_ctx_data : NULL; + if (branch_user_callstack(cpuc->br_sel)) + task_ctx->lbr_callstack_users++; + cpuc->lbr_users++; if (cpuc->lbr_users == 1) perf_sched_cb_enable(event->ctx->pmu); @@ -222,10 +232,15 @@ void intel_pmu_lbr_enable(struct perf_event *event) void intel_pmu_lbr_disable(struct perf_event *event) { struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events); + struct x86_perf_task_context *task_ctx; if (!x86_pmu.lbr_nr) return; + task_ctx = event->ctx ? event->ctx->task_ctx_data : NULL; + if (branch_user_callstack(cpuc->br_sel)) + task_ctx->lbr_callstack_users--; + cpuc->lbr_users--; WARN_ON_ONCE(cpuc->lbr_users < 0); -- 1.9.0 -- 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/