From: Ingo Molnar <mingo@elte.hu>
To: Valdis.Kletnieks@vt.edu
Cc: Andrew Morton <akpm@linux-foundation.org>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Steven Rostedt <rostedt@goodmis.org>,
linux-kernel@vger.kernel.org,
Frederic Weisbecker <fweisbec@gmail.com>
Subject: Re: [PATCH 5/5] ring-buffer: fix printk output
Date: Wed, 29 Apr 2009 22:15:55 +0200 [thread overview]
Message-ID: <20090429201555.GG17021@elte.hu> (raw)
In-Reply-To: <25555.1241021943@turing-police.cc.vt.edu>
* Valdis.Kletnieks@vt.edu <Valdis.Kletnieks@vt.edu> wrote:
> On Tue, 28 Apr 2009 23:20:00 PDT, Andrew Morton said:
> > printk_once() is racy on smp and preempt btw ;)
>
> Looks like at worst, it's prone to the usual printk racing, plus a
> possible misfire causing it to print twice before shutting up? Or
> is there something I'm missing here?
Yeah, that's the worst-case scenario.
Still worth improving if we can do it without bloating the code or
data.
[ If not, we can just assume the kernel is perfect and ignore all
the printk_once() and WARN_ONCE() / WARN_ON_ONCE() callsites as
obviously dead code ;-) ]
Ingo
next prev parent reply other threads:[~2009-04-29 20:16 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-29 4:48 [PATCH 0/5] [GIT PULL] tracing/splice/ringbuffer: updates for tip Steven Rostedt
2009-04-29 4:48 ` [PATCH 1/5] tracing: convert ftrace_dump spinlocks to raw Steven Rostedt
2009-04-29 5:07 ` Andrew Morton
2009-04-29 5:55 ` Ingo Molnar
2009-04-29 4:48 ` [PATCH 2/5] tracing: fix ref count in splice pages Steven Rostedt
2009-04-29 4:48 ` [PATCH 3/5] tracing: only add splice page if entries exist Steven Rostedt
2009-04-29 4:48 ` [PATCH 4/5] tracing: have splice only copy full pages Steven Rostedt
2009-04-29 4:48 ` [PATCH 5/5] ring-buffer: fix printk output Steven Rostedt
2009-04-29 5:20 ` Andrew Morton
2009-04-29 5:43 ` Ingo Molnar
2009-04-29 5:55 ` Andrew Morton
2009-04-29 6:09 ` Ingo Molnar
2009-04-29 6:20 ` Andrew Morton
2009-04-29 7:22 ` Ingo Molnar
2009-04-29 7:41 ` Andrew Morton
2009-04-29 9:56 ` Ingo Molnar
2009-04-29 15:09 ` Andrew Morton
2009-04-29 19:45 ` Ingo Molnar
2009-04-29 19:52 ` Andrew Morton
2009-04-29 20:11 ` Ingo Molnar
2009-04-29 16:19 ` Valdis.Kletnieks
2009-04-29 20:15 ` Ingo Molnar [this message]
2009-04-29 6:03 ` [PATCH 0/5] [GIT PULL] tracing/splice/ringbuffer: updates for tip Ingo Molnar
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=20090429201555.GG17021@elte.hu \
--to=mingo@elte.hu \
--cc=Valdis.Kletnieks@vt.edu \
--cc=akpm@linux-foundation.org \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=sfr@canb.auug.org.au \
/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