Re: OpenGL-based framebuffer concepts

[Jon Smirl]

On 6/1/06, Antonino A. Daplas <adaplas@xxxxxxxxx> wrote:
> Jon Smirl wrote:
> > On 6/1/06, D. Hazelton <dhazelton@xxxxxxxxx> wrote:
> >
> > Printk works from inside interrupt handlers currently. This is an
> > absolute requirement for kernel debugging that can't be removed.
> > Because of this requirement there has to be a way for all drivers to
> > draw the console entirely inside the kernel. You can not make calls to
> > user space from inside interrupt handlers.
> >
> >> > > 6) Things like panics should be visible no matter what is running. No
> >> > > more silent deaths.
> >
> > Panics can occur inside interrupt handlers. You can't queue up printks
> > in this context and they display them later, the kernel just died,
> > there is no later.
> >
>
> 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.

--
Jon Smirl
jonsmirl@xxxxxxxxx
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