From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752191AbdANMaE (ORCPT ); Sat, 14 Jan 2017 07:30:04 -0500 Received: from terminus.zytor.com ([198.137.202.10]:50856 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751926AbdANMaC (ORCPT ); Sat, 14 Jan 2017 07:30:02 -0500 Date: Sat, 14 Jan 2017 04:29:15 -0800 From: tip-bot for Jiri Olsa Message-ID: Cc: alexander.shishkin@linux.intel.com, mingo@kernel.org, acme@kernel.org, jolsa@redhat.com, tglx@linutronix.de, eranian@google.com, hpa@zytor.com, linux-kernel@vger.kernel.org, vince@deater.net, torvalds@linux-foundation.org, acme@redhat.com, jolsa@kernel.org, peterz@infradead.org, vincent.weaver@maine.edu Reply-To: vincent.weaver@maine.edu, jolsa@kernel.org, peterz@infradead.org, eranian@google.com, acme@redhat.com, vince@deater.net, torvalds@linux-foundation.org, hpa@zytor.com, linux-kernel@vger.kernel.org, acme@kernel.org, jolsa@redhat.com, alexander.shishkin@linux.intel.com, mingo@kernel.org, tglx@linutronix.de In-Reply-To: <1482931866-6018-2-git-send-email-jolsa@kernel.org> References: <1482931866-6018-2-git-send-email-jolsa@kernel.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf/x86/intel: Account interrupts for PEBS errors Git-Commit-ID: 475113d937adfd150eb82b5e2c5507125a68e7af 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 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 475113d937adfd150eb82b5e2c5507125a68e7af Gitweb: http://git.kernel.org/tip/475113d937adfd150eb82b5e2c5507125a68e7af Author: Jiri Olsa AuthorDate: Wed, 28 Dec 2016 14:31:03 +0100 Committer: Ingo Molnar CommitDate: Sat, 14 Jan 2017 11:06:49 +0100 perf/x86/intel: Account interrupts for PEBS errors It's possible to set up PEBS events to get only errors and not any data, like on SNB-X (model 45) and IVB-EP (model 62) via 2 perf commands running simultaneously: taskset -c 1 ./perf record -c 4 -e branches:pp -j any -C 10 This leads to a soft lock up, because the error path of the intel_pmu_drain_pebs_nhm() does not account event->hw.interrupt for error PEBS interrupts, so in case you're getting ONLY errors you don't have a way to stop the event when it's over the max_samples_per_tick limit: NMI watchdog: BUG: soft lockup - CPU#22 stuck for 22s! [perf_fuzzer:5816] ... RIP: 0010:[] [] smp_call_function_single+0xe2/0x140 ... Call Trace: ? trace_hardirqs_on_caller+0xf5/0x1b0 ? perf_cgroup_attach+0x70/0x70 perf_install_in_context+0x199/0x1b0 ? ctx_resched+0x90/0x90 SYSC_perf_event_open+0x641/0xf90 SyS_perf_event_open+0x9/0x10 do_syscall_64+0x6c/0x1f0 entry_SYSCALL64_slow_path+0x25/0x25 Add perf_event_account_interrupt() which does the interrupt and frequency checks and call it from intel_pmu_drain_pebs_nhm()'s error path. We keep the pending_kill and pending_wakeup logic only in the __perf_event_overflow() path, because they make sense only if there's any data to deliver. Signed-off-by: Jiri Olsa Signed-off-by: Peter Zijlstra (Intel) Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Cc: Vince Weaver Link: http://lkml.kernel.org/r/1482931866-6018-2-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/events/intel/ds.c | 6 +++++- include/linux/perf_event.h | 1 + kernel/events/core.c | 47 ++++++++++++++++++++++++++++++---------------- 3 files changed, 37 insertions(+), 17 deletions(-) diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c index be20239..9dfeeec 100644 --- a/arch/x86/events/intel/ds.c +++ b/arch/x86/events/intel/ds.c @@ -1389,9 +1389,13 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs) continue; /* log dropped samples number */ - if (error[bit]) + if (error[bit]) { perf_log_lost_samples(event, error[bit]); + if (perf_event_account_interrupt(event)) + x86_pmu_stop(event, 0); + } + if (counts[bit]) { __intel_pmu_pebs_event(event, iregs, base, top, bit, counts[bit]); diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 4741ecd..78ed810 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1259,6 +1259,7 @@ extern void perf_event_disable(struct perf_event *event); extern void perf_event_disable_local(struct perf_event *event); extern void perf_event_disable_inatomic(struct perf_event *event); extern void perf_event_task_tick(void); +extern int perf_event_account_interrupt(struct perf_event *event); #else /* !CONFIG_PERF_EVENTS: */ static inline void * perf_aux_output_begin(struct perf_output_handle *handle, diff --git a/kernel/events/core.c b/kernel/events/core.c index cbc5937..110b38a 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7060,25 +7060,12 @@ static void perf_log_itrace_start(struct perf_event *event) perf_output_end(&handle); } -/* - * Generic event overflow handling, sampling. - */ - -static int __perf_event_overflow(struct perf_event *event, - int throttle, struct perf_sample_data *data, - struct pt_regs *regs) +static int +__perf_event_account_interrupt(struct perf_event *event, int throttle) { - int events = atomic_read(&event->event_limit); struct hw_perf_event *hwc = &event->hw; - u64 seq; int ret = 0; - - /* - * Non-sampling counters might still use the PMI to fold short - * hardware counters, ignore those. - */ - if (unlikely(!is_sampling_event(event))) - return 0; + u64 seq; seq = __this_cpu_read(perf_throttled_seq); if (seq != hwc->interrupts_seq) { @@ -7106,6 +7093,34 @@ static int __perf_event_overflow(struct perf_event *event, perf_adjust_period(event, delta, hwc->last_period, true); } + return ret; +} + +int perf_event_account_interrupt(struct perf_event *event) +{ + return __perf_event_account_interrupt(event, 1); +} + +/* + * Generic event overflow handling, sampling. + */ + +static int __perf_event_overflow(struct perf_event *event, + int throttle, struct perf_sample_data *data, + struct pt_regs *regs) +{ + int events = atomic_read(&event->event_limit); + int ret = 0; + + /* + * Non-sampling counters might still use the PMI to fold short + * hardware counters, ignore those. + */ + if (unlikely(!is_sampling_event(event))) + return 0; + + ret = __perf_event_account_interrupt(event, throttle); + /* * XXX event_limit might not quite work as expected on inherited * events