Re: [lkcd-devel] Re: What's left over.

[Castor Fu]

On Thu, 31 Oct 2002, Linus Torvalds wrote:

>
> On Fri, 1 Nov 2002, Bill Davidsen wrote:
> >
> >   If you really believed the stuff you say you'd put it in and promise to
> > take it out if people didn't find it useful or there were inherent
> > limitations.
>
> This never works. Be honest. Nobody takes out features, they are stuck
> once they get in. Which is exactly why my job is to say "no", and why
> there is no "accepted unless proven bad".
>
> > It would probably take 10-30% off the time to a stable release.
>
> Talk is cheap.
>
> I've not seen a _single_ bug-report with a fix that attributed the
> existing LKCD patches. I might be more impressed if I had.

Maybe people don't bother to spell out how they got there.  Here's one.

    -castor

:: Newsgroups: mlist.linux.kernel
:: Date:   Mon, 17 Dec 2001 09:48:53 -0800 (PST)
:: From: Castor Fu <[e-mail]>
:: X-To: <[e-mail]>
:: Subject: i386 machine_restart unsafe in interrupt context
:: Message-ID: <[e-mail]>
:: MIME-Version: 1.0
:: Content-Type: TEXT/PLAIN; charset=US-ASCII
:: Approved: [e-mail]
:: Lines: 27
::
::
:: I have a problem where systems fail to reboot on panic().  I've resolved
:: it by changing smp_send_stop() to use an NMI (like the KDB patch does to
:: manage communication).
::
:: The source of the problem is that the panic path has the following:
::
::     panic()
::         machine_restart()
::             machine_real_restart()
::                 smp_send_stop()
::                     smp_call_function()
::
:: and smp_call_function() is not safe in an interrupt context.
::
:: I imagine people might want to handle this differently, but I'd be
:: happy to diffs if there's interest.  It may be that there are enough
:: cases like this that smp_call_function might want a version that
:: uses an NMI. . .
::
::     -Castor Fu
::     [e-mail]