Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754843AbaFWJEP (ORCPT ); Mon, 23 Jun 2014 05:04:15 -0400 Received: from ip4-83-240-18-248.cust.nbox.cz ([83.240.18.248]:55466 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752445AbaFWIc2 (ORCPT ); Mon, 23 Jun 2014 04:32:28 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Will Deacon , Jiri Slaby Subject: [PATCH 3.12 013/111] ARM: perf: hook up perf_sample_event_took around pmu irq handling Date: Mon, 23 Jun 2014 10:30:48 +0200 Message-Id: <22259d1fa4111413d7969bae6ad425fbc7fcf3e1.1403512281.git.jslaby@suse.cz> X-Mailer: git-send-email 2.0.0 In-Reply-To: <55d5f044a1fc96a74e4470e318c0a24f27a9ab7e.1403512280.git.jslaby@suse.cz> References: <55d5f044a1fc96a74e4470e318c0a24f27a9ab7e.1403512280.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Will Deacon 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 5f5092e72cc25a6a5785308270e0085b2b2772cc upstream. Since we indirect all of our PMU IRQ handling through a dispatcher, it's trivial to hook up perf_sample_event_took to prevent applications such as oprofile from generating interrupt storms due to an unrealisticly low sample period. Reported-by: Robert Richter Signed-off-by: Will Deacon Signed-off-by: Jiri Slaby --- arch/arm/kernel/perf_event.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c index e186ee1e63f6..de5cd767e4df 100644 --- a/arch/arm/kernel/perf_event.c +++ b/arch/arm/kernel/perf_event.c @@ -303,11 +303,18 @@ static irqreturn_t armpmu_dispatch_irq(int irq, void *dev) struct arm_pmu *armpmu = (struct arm_pmu *) dev; struct platform_device *plat_device = armpmu->plat_device; struct arm_pmu_platdata *plat = dev_get_platdata(&plat_device->dev); + int ret; + u64 start_clock, finish_clock; + start_clock = sched_clock(); if (plat && plat->handle_irq) - return plat->handle_irq(irq, dev, armpmu->handle_irq); + ret = plat->handle_irq(irq, dev, armpmu->handle_irq); else - return armpmu->handle_irq(irq, dev); + ret = armpmu->handle_irq(irq, dev); + finish_clock = sched_clock(); + + perf_sample_event_took(finish_clock - start_clock); + return ret; } static void -- 2.0.0 -- 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/