On Thu, Jun 27, 2002 at 01:22:03PM -0700, Jason R Thorpe wrote:
> On Thu, Jun 27, 2002 at 10:07:50PM +0200, Jaromir Dolecek wrote:
> 
>  > 	switch (retval) {
>  > 	case ERROR:
>  > 	    {
>  > 		char buf[256], *errbuf = &buf;
>  > 		/* do error handling */
>  > 		break;
>  > 	    }
> 
> I don't think it would.  The compiler may allocate stack frame space for
> that anyway.
> 
> Use of alloca() is one possibility.  But that still comes from the stack,
> do you'd want to make the buffer smaller, as well, I guess.
> 
> Reducing kernel stack usage is good ... but having to allocate memory
> in an error handler doesn't seem like the best idea...

Well its not a performance critical piece of code, and it is (probably)
unlikely that lack of memory is responsible for a disk error.
(and not to be reported elsewhere).

OTOH it might be 'safe' to use a static buffer and not care
about the garbled messages that might occurr.
Could even lock the static buffer!
Maybe you could guarantee that the lack of in kernal pre-emption
means that the buffer is never reused?

	David

-- 
David Laight: david@l8s.co.uk