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Message-ID: <9e4733910606011448x32246dfcy2a2d448e238bdab3@mail.gmail.com>
Date: Thu, 1 Jun 2006 17:48:57 -0400
From: "Jon Smirl" <jonsmirl@gmail.com>
To: "Antonino A. Daplas" <adaplas@gmail.com>
Subject: Re: OpenGL-based framebuffer concepts
Cc: "D. Hazelton" <dhazelton@enter.net>,
       "David Lang" <dlang@digitalinsight.com>,
       "Ondrej Zajicek" <santiago@mail.cz>, "Dave Airlie" <airlied@gmail.com>,
       "Pavel Machek" <pavel@ucw.cz>, "Alan Cox" <alan@lxorguk.ukuu.org.uk>,
       "Kyle Moffett" <mrmacman_g4@mac.com>,
       "Manu Abraham" <abraham.manu@gmail.com>,
       "linux cbon" <linuxcbon@yahoo.fr>,
       "Helge Hafting" <helge.hafting@aitel.hist.no>, Valdis.Kletnieks@vt.edu,
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On 6/1/06, Antonino A. Daplas <adaplas@gmail.com> wrote:
> Jon Smirl wrote:
> > On 6/1/06, Antonino A. Daplas <adaplas@gmail.com> wrote:
> >> Jon Smirl wrote:
> >> > On 6/1/06, D. Hazelton <dhazelton@enter.net> wrote:
> >> >
> >>
> >> Console writes are done with the console semaphore held. printk will also
> >> just write to the log buffer and defer the actual console printing
> >> for later, by the next or current process that will grab the semaphore.
> >
> > That was my original position too. But Alan Cox has drilled it into me
> > that this is not acceptable for printks in interrupt context, they
> > need to print there and not be deferred.
> >
>
> Just to clarify, it's not my position, that's how the current printk code
> works.

I haven't looked at the code, but if there is just normal console
running and nothing like X is around, doesn't the console system
always have the semaphore? If it always has the semaphore then
interupt context printk's aren't blocked.

I think that interrupt context printk's work today, I have definitely
seen one printk get inserted into the middle of another on my console.
How else could you achieve that?

-- 
Jon Smirl
jonsmirl@gmail.com