From: Rusty Russell <rusty@rustcorp.com.au>
To: Andrew Morton <akpm@osdl.org>
Cc: vatsa@in.ibm.com, mingo@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: more efficient current_is_keventd macro? [was Re: [lhcs-devel] Re: Kthread_create() never returns when called from worker_thread]
Date: Tue, 09 Mar 2004 12:50:39 +1100 [thread overview]
Message-ID: <1078797038.18171.707.camel@bach> (raw)
In-Reply-To: <20040308143658.25c1d378.akpm@osdl.org>
On Tue, 2004-03-09 at 09:36, Andrew Morton wrote:
> Srivatsa Vaddagiri <vatsa@in.ibm.com> wrote:
> > int current_is_keventd(void)
> > {
> > + int cpu = smp_processor_id();
> > + cwq = keventd_wq->cpu_wq + cpu;
> > + if (current == cwq->thread)
> > + return 1;
> > + else
> > + return 0;
> > }
>
> Is racy in the presence of preemption.
Actually, it's not, because if current *is* keventd we're nailed to the
CPU, and if it's not, we're going to return false either way.
But it *should* be fixed, simply as an example to others.
Cheers,
Rusty.
--
Anyone who quotes me in their signature is an idiot -- Rusty Russell
next prev parent reply other threads:[~2004-03-09 1:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-08 12:30 more efficient current_is_keventd macro? [was Re: [lhcs-devel] Re: Kthread_create() never returns when called from worker_thread] Srivatsa Vaddagiri
2004-03-08 22:36 ` Andrew Morton
2004-03-09 1:50 ` Rusty Russell [this message]
2004-03-09 13:40 ` Srivatsa Vaddagiri
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=1078797038.18171.707.camel@bach \
--to=rusty@rustcorp.com.au \
--cc=akpm@osdl.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=vatsa@in.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox