Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753016AbdLNUVB (ORCPT ); Thu, 14 Dec 2017 15:21:01 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:58982 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752046AbdLNUU4 (ORCPT ); Thu, 14 Dec 2017 15:20:56 -0500 Smtp-Origin-Hostprefix: devbig From: Teng Qin Smtp-Origin-Hostname: devbig473.prn1.facebook.com To: CC: , , , , , , , Teng Qin Smtp-Origin-Cluster: prn1c29 Subject: [PATCH tip 3/3] Improve sched_process_exit Tracepoint Date: Thu, 14 Dec 2017 12:20:44 -0800 Message-ID: <20171214202044.1629279-4-qinteng@fb.com> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20171214202044.1629279-1-qinteng@fb.com> References: <20171214202044.1629279-1-qinteng@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-12-14_12:,, signatures=0 X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2359 Lines: 85 This commit adds group_dead value to sched_process_exit's Tracepoint struct. The value is passed as an argument of the Tracepoint. It is useful to differentiate exits of a regular process or the last process of the process group. This commit also exposes pointers of exited task. BPF program can read task information via task struct pointer. Exposing the pointer explicitly gives BPF programs an easy and reliable way of using the Tracepoint. Signed-off-by: Teng Qin --- include/trace/events/sched.h | 37 +++++++++++++++++++++++++++++-------- kernel/exit.c | 2 +- 2 files changed, 30 insertions(+), 9 deletions(-) diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index e8bb6b0..c741f4e 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -204,6 +204,35 @@ TRACE_EVENT(sched_migrate_task, __entry->orig_cpu, __entry->dest_cpu) ); +/* + * Tracepoint for a task exiting: + */ +TRACE_EVENT(sched_process_exit, + + TP_PROTO(struct task_struct *p, bool group_dead), + + TP_ARGS(p, group_dead), + + TP_STRUCT__entry( + __array( char, comm, TASK_COMM_LEN ) + __field( pid_t, pid ) + __field( int, prio ) + __field( bool, group_dead ) + __field( void *, task_struct ) + ), + + TP_fast_assign( + memcpy(__entry->comm, p->comm, TASK_COMM_LEN); + __entry->pid = p->pid; + __entry->prio = p->prio; + __entry->group_dead = group_dead; + __entry->task_struct = (void *)p; + ), + + TP_printk("comm=%s pid=%d prio=%d", + __entry->comm, __entry->pid, __entry->prio) +); + DECLARE_EVENT_CLASS(sched_process_template, TP_PROTO(struct task_struct *p), @@ -233,14 +262,6 @@ DEFINE_EVENT(sched_process_template, sched_process_free, TP_PROTO(struct task_struct *p), TP_ARGS(p)); - -/* - * Tracepoint for a task exiting: - */ -DEFINE_EVENT(sched_process_template, sched_process_exit, - TP_PROTO(struct task_struct *p), - TP_ARGS(p)); - /* * Tracepoint for waiting on task to unschedule: */ diff --git a/kernel/exit.c b/kernel/exit.c index 6b4298a..b613594 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -853,7 +853,7 @@ void __noreturn do_exit(long code) if (group_dead) acct_process(); - trace_sched_process_exit(tsk); + trace_sched_process_exit(tsk, group_dead); exit_sem(tsk); exit_shm(tsk); -- 2.9.5