Re: [PATCH] printk: Remove separate printk_sched buffers and use printk buf instead

Steven Rostedt
2014-05-05T23:55:17Z

On Mon, 05 May 2014 16:33:51 -0700
Joe Perches <joe@perches.com> wrote:

> On Mon, 2014-05-05 at 19:18 -0400, Steven Rostedt wrote:
> > To prevent deadlocks with doing a printk inside the scheduler,
> > printk_sched() was created. The issue is that printk has a console_sem
> > that it can grab and release. The release does a wake up if there's a
> > task pending on the sem, and this wake up grabs the rq locks that is
> > held in the scheduler. This leads to a possible deadlock if the wake up
> > uses the same rq as the one with the rq lock held already.
> []
> > kernel/printk/printk.c | 87 +++++++++++++++++++++++++++++++------------------
> []
> > @@ -2440,18 +2470,20 @@
> > #define PRINTK_BUF_SIZE 512
>
> Wouldn't this define be unused and shouldn't it be deleted too?
>

I guess it would.

-- Steve