From: Andrew Morton <akpm@linux-foundation.org>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Gilad Ben-Yossef <gilad@benyossef.com>,
Thomas Gleixner <tglx@linutronix.de>,
Steven Rostedt <rostedt@goodmis.org>,
Peter Zijlstra <peterz@infradead.org>,
Li Zhong <zhong@linux.vnet.ibm.com>
Subject: Re: [PATCH] context_tracking: Add comments on interface and internals
Date: Thu, 13 Dec 2012 15:00:15 -0800 [thread overview]
Message-ID: <20121213150015.e497a585.akpm@linux-foundation.org> (raw)
In-Reply-To: <CAFTL4hxPAq0pNOAhMc01iOygqdx=Ja=b5u9ozzdRmPLbtxMn+A@mail.gmail.com>
On Thu, 13 Dec 2012 23:50:23 +0100
Frederic Weisbecker <fweisbec@gmail.com> wrote:
> >
> >> + * This call supports re-entrancy.
> >
> > Presumably the explanation for user_exit() applies here.
>
> Not sure what you mean here.
It's unclear what it means to say "user_enter() supports reentrancy".
I mean, zillions of kernel functions are surely reentrant - so what?
It appears that you had something in mind when pointing this out, but
what was it? The comment over user_exit() appears to tell us.
> > It's mainly this bit which makes me wonder why the code is in lib/. Is
> > there any conceivable prospect that any other subsystem will use this
> > code for anything?
>
> So that's because of that cputime accounting on dynticks CPUs which
> will need to know about user/kernel transitions. I'm preparing that
> for the 3.9 merge window.
Oh. That's really the entire reason for the patch and should have been
in the changelog!
next prev parent reply other threads:[~2012-12-13 23:00 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-13 20:57 [PATCH] context_tracking: Add comments on interface and internals Frederic Weisbecker
2012-12-13 21:18 ` Andrew Morton
2012-12-13 22:50 ` Frederic Weisbecker
2012-12-13 23:00 ` Andrew Morton [this message]
2012-12-13 23:10 ` Frederic Weisbecker
-- strict thread matches above, loose matches on Subject: below --
2013-01-16 12:32 Frederic Weisbecker
2013-01-16 13:04 ` Namhyung Kim
2013-01-16 14:58 ` Frederic Weisbecker
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=20121213150015.e497a585.akpm@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=fweisbec@gmail.com \
--cc=gilad@benyossef.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=tglx@linutronix.de \
--cc=zhong@linux.vnet.ibm.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.