From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753992Ab3LRKcZ (ORCPT ); Wed, 18 Dec 2013 05:32:25 -0500 Received: from terminus.zytor.com ([198.137.202.10]:44641 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753962Ab3LRKcW (ORCPT ); Wed, 18 Dec 2013 05:32:22 -0500 Date: Wed, 18 Dec 2013 02:31:41 -0800 From: tip-bot for Alexander Shishkin Message-ID: Cc: linux-kernel@vger.kernel.org, eranian@google.com, paulus@samba.org, hpa@zytor.com, mingo@kernel.org, efault@gmx.de, peterz@infradead.org, alexander.shishkin@linux.intel.com, fweisbec@gmail.com, ak@linux.intel.com, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, paulus@samba.org, eranian@google.com, linux-kernel@vger.kernel.org, peterz@infradead.org, efault@gmx.de, alexander.shishkin@linux.intel.com, fweisbec@gmail.com, ak@linux.intel.com, tglx@linutronix.de In-Reply-To: <1387196256-8030-1-git-send-email-alexander.shishkin@linux.intel.com> References: <1387196256-8030-1-git-send-email-alexander.shishkin@linux.intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf: Disable all pmus on unthrottling and rescheduling Git-Commit-ID: 443772776c69ac9293d66b4d69fd9af16299cc2a X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.1 (terminus.zytor.com [127.0.0.1]); Wed, 18 Dec 2013 02:31:47 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 443772776c69ac9293d66b4d69fd9af16299cc2a Gitweb: http://git.kernel.org/tip/443772776c69ac9293d66b4d69fd9af16299cc2a Author: Alexander Shishkin AuthorDate: Mon, 16 Dec 2013 14:17:36 +0200 Committer: Ingo Molnar CommitDate: Tue, 17 Dec 2013 15:04:00 +0100 perf: Disable all pmus on unthrottling and rescheduling Currently, only one PMU in a context gets disabled during unthrottling and event_sched_{out,in}(), however, events in one context may belong to different pmus, which results in PMUs being reprogrammed while they are still enabled. This means that mixed PMU use [which is rare in itself] resulted in potentially completely unreliable results: corrupted events, bogus results, etc. This patch temporarily disables PMUs that correspond to each event in the context while these events are being modified. Signed-off-by: Alexander Shishkin Reviewed-by: Andi Kleen Signed-off-by: Peter Zijlstra Cc: Frederic Weisbecker Cc: Mike Galbraith Cc: Paul Mackerras Cc: Stephane Eranian Cc: Alexander Shishkin Link: http://lkml.kernel.org/r/1387196256-8030-1-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar --- kernel/events/core.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 72348dc..f574401 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -1396,6 +1396,8 @@ event_sched_out(struct perf_event *event, if (event->state != PERF_EVENT_STATE_ACTIVE) return; + perf_pmu_disable(event->pmu); + event->state = PERF_EVENT_STATE_INACTIVE; if (event->pending_disable) { event->pending_disable = 0; @@ -1412,6 +1414,8 @@ event_sched_out(struct perf_event *event, ctx->nr_freq--; if (event->attr.exclusive || !cpuctx->active_oncpu) cpuctx->exclusive = 0; + + perf_pmu_enable(event->pmu); } static void @@ -1652,6 +1656,7 @@ event_sched_in(struct perf_event *event, struct perf_event_context *ctx) { u64 tstamp = perf_event_time(event); + int ret = 0; if (event->state <= PERF_EVENT_STATE_OFF) return 0; @@ -1674,10 +1679,13 @@ event_sched_in(struct perf_event *event, */ smp_wmb(); + perf_pmu_disable(event->pmu); + if (event->pmu->add(event, PERF_EF_START)) { event->state = PERF_EVENT_STATE_INACTIVE; event->oncpu = -1; - return -EAGAIN; + ret = -EAGAIN; + goto out; } event->tstamp_running += tstamp - event->tstamp_stopped; @@ -1693,7 +1701,10 @@ event_sched_in(struct perf_event *event, if (event->attr.exclusive) cpuctx->exclusive = 1; - return 0; +out: + perf_pmu_enable(event->pmu); + + return ret; } static int @@ -2743,6 +2754,8 @@ static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, if (!event_filter_match(event)) continue; + perf_pmu_disable(event->pmu); + hwc = &event->hw; if (hwc->interrupts == MAX_INTERRUPTS) { @@ -2752,7 +2765,7 @@ static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, } if (!event->attr.freq || !event->attr.sample_freq) - continue; + goto next; /* * stop the event and update event->count @@ -2774,6 +2787,8 @@ static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx, perf_adjust_period(event, period, delta, false); event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0); + next: + perf_pmu_enable(event->pmu); } perf_pmu_enable(ctx->pmu);