Subject: Re: CVS commit: src/sys/arch/xen
To: None <email@example.com>
From: YAMAMOTO Takashi <firstname.lastname@example.org>
Date: 08/22/2005 21:33:08
> > - there is no recovery in the case of failure of MEMOP_increase_reservation.
> > is this intended?
> There's no recovery needed. We lost these pages, they are marked as
> allocated in UVM so that's OK. We could eventually reallocate the pages one by
> one, but I'm not sure it's worth it as it's not something that should
> happen anyway.
assuming that xen's buddy allocator has the same characteristics as
linux's, "high-order" allocation failure is something that likely
happens on long run.
> > i think it's better to do MEMOP_decrease_reservation
> > only when MEMOP_increase_reservation succeeded.
> > MEMOP_decrease_reservation unlikely helps MEMOP_increase_reservation
> > anyway.
> MEMOP_increase_reservation won't work if we didn't give enouth page
> back first, because the hypervisor won't allow a domain to increase
> its number of pages past the configured limit (and a domain starts with
> this number of pages allocated).
ok, i overlooked the limit. thanks.