From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9CEC6C04FE0 for ; Wed, 2 Aug 2023 15:06:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233943AbjHBPG4 (ORCPT ); Wed, 2 Aug 2023 11:06:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234304AbjHBPGb (ORCPT ); Wed, 2 Aug 2023 11:06:31 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 402A630FF; Wed, 2 Aug 2023 08:05:57 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D1454619C8; Wed, 2 Aug 2023 15:05:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9FCABC433C8; Wed, 2 Aug 2023 15:05:54 +0000 (UTC) Date: Wed, 2 Aug 2023 11:05:52 -0400 From: Steven Rostedt To: Ze Gao Cc: Adrian Hunter , Alexander Shishkin , Arnaldo Carvalho de Melo , Ian Rogers , Ingo Molnar , Jiri Olsa , Mark Rutland , Masami Hiramatsu , Namhyung Kim , Peter Zijlstra , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-trace-devel@vger.kernel.org, Ze Gao Subject: Re: [RFC PATCH v4 4/7] sched, tracing: reorganize fields of switch event struct Message-ID: <20230802110552.768f0487@gandalf.local.home> In-Reply-To: <20230802121116.324604-5-zegao@tencent.com> References: <20230802121116.324604-1-zegao@tencent.com> <20230802121116.324604-5-zegao@tencent.com> X-Mailer: Claws Mail 3.19.1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On Wed, 2 Aug 2023 08:09:59 -0400 Ze Gao wrote: > From: Ze Gao > > Report priorities in 'short' and prev_state in 'int' to save > some buffer space. And also reorder the fields so that we take > struct alignment into consideration to make the record compact. > > Suggested-by: Steven Rostedt (Google) > Signed-off-by: Ze Gao > --- > include/trace/events/sched.h | 24 ++++++++++++------------ > 1 file changed, 12 insertions(+), 12 deletions(-) > > diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h > index fbb99a61f714..7d34db20b2c6 100644 > --- a/include/trace/events/sched.h > +++ b/include/trace/events/sched.h > @@ -187,7 +187,7 @@ DEFINE_EVENT(sched_wakeup_template, sched_wakeup_new, > TP_ARGS(p)); > > #ifdef CREATE_TRACE_POINTS > -static inline long __trace_sched_switch_state(bool preempt, > +static inline int __trace_sched_switch_state(bool preempt, > unsigned int prev_state, > struct task_struct *p) > { > @@ -229,23 +229,23 @@ TRACE_EVENT(sched_switch, > TP_ARGS(preempt, prev, next, prev_state), > > TP_STRUCT__entry( > - __array( char, prev_comm, TASK_COMM_LEN ) > __field( pid_t, prev_pid ) > - __field( int, prev_prio ) > - __field( long, prev_state ) > - __array( char, next_comm, TASK_COMM_LEN ) > __field( pid_t, next_pid ) > - __field( int, next_prio ) > + __field( short, prev_prio ) > + __field( short, next_prio ) > + __field( int, prev_state ) I was talking with Peter on IRC and since the biggest number that prev_state can be is TASK_REPORT_MASK which is 0x100, I think we can make prev_state into a short as well. -- Steve > + __array( char, prev_comm, TASK_COMM_LEN ) > + __array( char, next_comm, TASK_COMM_LEN ) > ), > > TP_fast_assign( > - memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN); > - __entry->prev_pid = prev->pid; > - __entry->prev_prio = prev->prio; > - __entry->prev_state = __trace_sched_switch_state(preempt, prev_state, prev); > + __entry->prev_pid = prev->pid; > + __entry->next_pid = next->pid; > + __entry->prev_prio = (short) prev->prio; > + __entry->next_prio = (short) next->prio; > + __entry->prev_state = __trace_sched_switch_state(preempt, prev_state, prev); > memcpy(__entry->prev_comm, prev->comm, TASK_COMM_LEN); > - __entry->next_pid = next->pid; > - __entry->next_prio = next->prio; > + memcpy(__entry->next_comm, next->comm, TASK_COMM_LEN); > /* XXX SCHED_DEADLINE */ > ), >