From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Jiri Olsa <jolsa@redhat.com>, Jiri Olsa <jolsa@kernel.org>,
linux-rt-users@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Juri Lelli <juri.lelli@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>
Subject: Re: [PATCH RT] tracing: make preempt_lazy and migrate_disable counter smaller
Date: Fri, 21 Feb 2020 21:20:53 +0100 [thread overview]
Message-ID: <20200221202053.egb5mv62fisdvk2f@linutronix.de> (raw)
In-Reply-To: <20200221145148.26d9550b@gandalf.local.home>
On 2020-02-21 14:51:48 [-0500], Steven Rostedt wrote:
> On Fri, 21 Feb 2020 18:44:19 +0100
> Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote:
>
> > diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
> > index f3b1ef07e4a5f..c8b3f06cb5ed7 100644
> > --- a/include/linux/trace_events.h
> > +++ b/include/linux/trace_events.h
> > @@ -62,9 +62,9 @@ struct trace_entry {
> > unsigned char flags;
> > unsigned char preempt_count;
> > int pid;
> > - unsigned short migrate_disable;
> > - unsigned short padding;
> > + unsigned char migrate_disable;
> > unsigned char preempt_lazy_count;
> > + unsigned short padding;
> > };
>
> Do we really need the padding here?
Not really. The two bytes are consumed since there is __packed so that
padding makes it just more obvious. However that padding wasn't used in
the past. I can remove it if you want.
The struct can't be __packed to save additional two bytes, correct?
> -- Steve
Sebastian
next prev parent reply other threads:[~2020-02-21 20:20 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-21 15:35 [PATCH] tracing: Fix trace entry and trace common fields for preempt_lazy_count Jiri Olsa
2020-02-21 15:49 ` Steven Rostedt
2020-02-21 16:10 ` Jiri Olsa
2020-02-21 16:21 ` Steven Rostedt
2020-02-21 16:29 ` Jiri Olsa
2020-02-21 16:50 ` Steven Rostedt
2020-02-21 16:37 ` Sebastian Andrzej Siewior
2020-02-21 17:44 ` [PATCH RT] tracing: make preempt_lazy and migrate_disable counter smaller Sebastian Andrzej Siewior
2020-02-21 19:51 ` Steven Rostedt
2020-02-21 20:20 ` Sebastian Andrzej Siewior [this message]
2020-02-21 20:49 ` Jiri Olsa
2020-02-24 10:01 ` Sebastian Andrzej Siewior
2020-02-24 11:54 ` Jiri Olsa
2020-02-24 17:01 ` [PATCH RT v2] " Sebastian Andrzej Siewior
2020-03-09 12:30 ` Jiri Olsa
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200221202053.egb5mv62fisdvk2f@linutronix.de \
--to=bigeasy@linutronix.de \
--cc=acme@kernel.org \
--cc=jolsa@kernel.org \
--cc=jolsa@redhat.com \
--cc=juri.lelli@redhat.com \
--cc=linux-rt-users@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).