From: Andrew Morton <akpm@linux-foundation.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, "Ingo Molnar" <mingo@kernel.org>,
"Frederic Weisbecker" <fweisbec@gmail.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Abderrahmane Benbachir" <abderrahmane.benbachir@polymtl.ca>,
"Américo Wang" <xiyou.wangcong@gmail.com>,
"Peter Zijlstra" <peterz@infradead.org>
Subject: Re: [PATCH 0/3] [RFC] init, tracing: Add initcall trace events
Date: Fri, 23 Mar 2018 12:50:16 -0700 [thread overview]
Message-ID: <20180323125016.270ea1558fe2499b1a12bfd7@linux-foundation.org> (raw)
In-Reply-To: <20180323150241.878778199@goodmis.org>
On Fri, 23 Mar 2018 11:02:41 -0400 Steven Rostedt <rostedt@goodmis.org> wrote:
> A while ago we had a boot tracer. But it was eventually removed:
> commit 30dbb20e68e6f ("tracing: Remove boot tracer").
>
> The rational was because there is already a initcall_debug boot option
> that causes printk()s of all the initcall functions.
"rationale" :)
> The problem with the initcall_debug option is that printk() is awfully slow,
> and makes it difficult to see the real impact of initcalls. Mainly because
> a single printk() is usually slower than most initcall functions.
Not understanding this. We do it correctly:
calltime = ktime_get();
ret = fn();
rettime = ktime_get();
so the displayed initcall timing is independent of the printk()
execution time?
next prev parent reply other threads:[~2018-03-23 19:50 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-23 15:02 [PATCH 0/3] [RFC] init, tracing: Add initcall trace events Steven Rostedt
2018-03-23 15:02 ` [PATCH 1/3] init: Fix initcall0 name as it is "pure" not "early" Steven Rostedt
2018-03-23 15:02 ` [PATCH 2/3] init, tracing: Add initcall trace events Steven Rostedt
2018-03-23 15:02 ` [PATCH 3/3] init, tracing: instrument security and console " Steven Rostedt
2018-03-23 19:50 ` Andrew Morton [this message]
2018-03-23 20:04 ` [PATCH 0/3] [RFC] init, tracing: Add " Steven Rostedt
2018-03-26 8:42 ` Peter Zijlstra
2018-03-26 14:34 ` Steven Rostedt
2018-03-26 17:47 ` [PATCH 4/3] init, tracing: Have printk come through the trace events for initcall_debug Steven Rostedt
2018-03-27 1:50 ` [PATCH 0/3] [RFC] init, tracing: Add initcall trace events Joel Fernandes (Google)
2018-03-27 3:02 ` Steven Rostedt
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=20180323125016.270ea1558fe2499b1a12bfd7@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=abderrahmane.benbachir@polymtl.ca \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=xiyou.wangcong@gmail.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.