Re: [PATCH 1/3] PCI: vpd handle longer delays in access

[Stephen Hemminger]

On Mon, 8 Sep 2008 13:40:25 -0700
Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Thu, 04 Sep 2008 13:56:37 -0700
> Stephen Hemminger <shemminger@xxxxxxxxxx> wrote:
> 
> > Accessing the VPD area can take a long time.  The existing 
> > VPD access code fails consistently on my hardware. There are comments
> > in the SysKonnect vendor driver that it can take up to 13ms per word. 
> > 
> > Change the access routines to:
> >   * use a mutex rather than spinning with IRQ's disabled and lock held
> >   * have a longer timeout
> >   * call schedule while spinning to provide some responsivness
> 
> It doesn't call schedule() - it calls yield().
> 
> yield() is pretty notoriously badly behaved in the presence of lots of
> runnable tasks and there's been a general move to eradicate its
> in-kernel callsites.
> 
> An alternative would be nice.

What is a good way to say "i am polling for a while"?
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