Re: xen-backend

[Christoph Egger <Christoph_Egger%gmx.de@localhost>]

Christoph Egger wrote:
> Jean-Yves Migeon wrote:
> > Christoph Egger wrote:
> > > I identified the debug printf's that make it work. See attached diff.
> > > Commenting out one of them or both results in *xenbus_create not 
> > > being called and produces a "Hotplug scripts not working" error.
> > >
> > > A comparison of the assembler snippet in xenbus_probe_init:
> > >
> > > [assembly]
> > >
> > > Anyone seeing the impact ?
> > Well, I do not see anything suspicious in this assembly? I am perhaps 
> > missing something?
> >
> > Question though: does it fix the bug (*xenbus_create not being called) 
> > only by using these printf's, or replacing them with some 
> > DELAY(whatever), __insn_barrier() or x86_lfence() has any effect?
>
> __insn_barrier() and x86_mfence() have no effect at all on both printf's.
>
> Both printf's can be replaced with DELAY(31), where 31 is the lowest
> possible number. 30 and lower values don't work.

Problem fixed in
sys/arch/xen/xenbus/xenbus_probe.c, rev. 1.21.

Christoph