From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751761AbeCVQLQ (ORCPT ); Thu, 22 Mar 2018 12:11:16 -0400 Received: from mga04.intel.com ([192.55.52.120]:35344 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751319AbeCVQLM (ORCPT ); Thu, 22 Mar 2018 12:11:12 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,345,1517904000"; d="scan'208";a="27170323" Subject: [PATCH v2 1/3] perf/core: store context switch out type into Perf trace From: Alexey Budankov To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo Cc: Alexander Shishkin , Jiri Olsa , Namhyung Kim , linux-kernel , Andi Kleen References: <713750a0-7cc1-0a27-7253-12ff4f3c9a8d@linux.intel.com> Organization: Intel Corp. Message-ID: <94a1fd9d-f3b1-156a-589b-a8dc9c17464b@linux.intel.com> Date: Thu, 22 Mar 2018 19:11:07 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <713750a0-7cc1-0a27-7253-12ff4f3c9a8d@linux.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Store thread context-switch-out event type into Perf trace as a part of PERF_RECORD_SWITCH[_CPU_WIDE] records. Introduced types of switch-out events assumed to be a) preempt: task->state == TASK_RUNNING and b) yield: !preempt; New yield event type is encoded using special PERF_RECORD_MISC_SWITCH_OUT_YIELD bit extending PERF_RECORD_MISC_SWITCH_OUT meaning traditional preemption switch out event: misc &= PERF_RECORD_MISC_SWITCH_OUT | PERF_RECORD_MISC_SWITCH_OUT_YIELD Signed-off-by: Alexey Budankov --- include/uapi/linux/perf_event.h | 5 +++++ kernel/events/core.c | 4 +++- tools/include/uapi/linux/perf_event.h | 5 +++++ 3 files changed, 13 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 912b85b52344..f5dd823d0ff1 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -655,6 +655,11 @@ struct perf_event_mmap_page { * perf_event_attr::precise_ip. */ #define PERF_RECORD_MISC_EXACT_IP (1 << 14) +/* + * Indicates that thread explicitly yielded cpu due to + * a call of some synchronization API e.g. futex system call + */ +#define PERF_RECORD_MISC_SWITCH_OUT_YIELD (1 << 14) /* * Reserve the last bit to indicate some extended misc field */ diff --git a/kernel/events/core.c b/kernel/events/core.c index 74a6e8f12a3c..f15af15af474 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7556,6 +7556,8 @@ static void perf_event_switch(struct task_struct *task, struct task_struct *next_prev, bool sched_in) { struct perf_switch_event switch_event; + __u16 switch_type = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT | + (task->state == TASK_RUNNING ? 0 : PERF_RECORD_MISC_SWITCH_OUT_YIELD); /* N.B. caller checks nr_switch_events != 0 */ @@ -7565,7 +7567,7 @@ static void perf_event_switch(struct task_struct *task, .event_id = { .header = { /* .type */ - .misc = sched_in ? 0 : PERF_RECORD_MISC_SWITCH_OUT, + .misc = switch_type, /* .size */ }, /* .next_prev_pid */ diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h index 912b85b52344..f5dd823d0ff1 100644 --- a/tools/include/uapi/linux/perf_event.h +++ b/tools/include/uapi/linux/perf_event.h @@ -655,6 +655,11 @@ struct perf_event_mmap_page { * perf_event_attr::precise_ip. */ #define PERF_RECORD_MISC_EXACT_IP (1 << 14) +/* + * Indicates that thread explicitly yielded cpu due to + * a call of some synchronization API e.g. futex system call + */ +#define PERF_RECORD_MISC_SWITCH_OUT_YIELD (1 << 14) /* * Reserve the last bit to indicate some extended misc field */