Re: [Xen-devel] [timer/ticks related] dom0 hang during boot on large 1TB system

["Jan Beulich" <JBeulich@xxxxxxxxxx>]

>>> Keir Fraser <keir.fraser@xxxxxxxxxxxxx> 22.12.09 11:20 >>>
>On 22/12/2009 08:51, "Jan Beulich" <JBeulich@xxxxxxxxxx> wrote:
>
>>> Then scrub_heap_pages() occurs which eats up a lot of time.
>> 
>> ... and confuses Xen's own time keeping (because, depending on
>> the platform timer used and it's wrap-around interval, a wrap may
>> be missed if process_pending_timers() isn't being executed
>> frequently enough.
>
>Process_pending_timers() has been called on every iteration of the scrub
>loop for as long as I can remember. I believe it was even you who added it.

Should I have overlooked it? Indeed, I did (I looked at the end of the
loop, while it's sitting at the beginning). I'm really sorry for the noise
then.

Nevertheless I remain convinced that the problem ought not to be fixed
by a kernel change (and even less by one that modifies Xen-unspecific
code). Any patch to this effect, unless I should be convinced otherwise,
has my explicit up front NAK (in case this counts anything).

And then it should be possible to simulate the problem quite easily on
a system with much less memory, by slowing down the scrub loop
artificially. If I find time before the holiday break I'll try to do that and
see if I can convince myself otherwise (as per above).
artificially

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel