Re: [Xen-devel] superpages lost after migration of HVM domU

2017-04-28 Thread Olaf Hering
On Wed, Apr 26, Andrew Cooper wrote: > On 26/04/17 16:43, Olaf Hering wrote: > > On Thu, Apr 20, Jan Beulich wrote: > > > > On 20.04.17 at 18:04, wrote: > >>> On Thu, Apr 20, Andrew Cooper wrote: > >>> > As it currently stands, the sending side iterates from 0 to p2m_size, > and sen

Re: [Xen-devel] superpages lost after migration of HVM domU

2017-04-26 Thread Andrew Cooper
On 26/04/17 16:43, Olaf Hering wrote: > On Thu, Apr 20, Jan Beulich wrote: > > On 20.04.17 at 18:04, wrote: >>> On Thu, Apr 20, Andrew Cooper wrote: >>> As it currently stands, the sending side iterates from 0 to p2m_size, and sends every frame on the first pass. This means we get P

Re: [Xen-devel] superpages lost after migration of HVM domU

2017-04-26 Thread Olaf Hering
On Thu, Apr 20, Jan Beulich wrote: > >>> On 20.04.17 at 18:04, wrote: > > On Thu, Apr 20, Andrew Cooper wrote: > > > >> As it currently stands, the sending side iterates from 0 to p2m_size, > >> and sends every frame on the first pass. This means we get PAGE_DATA > >> records linearly, in batch

Re: [Xen-devel] superpages lost after migration of HVM domU

2017-04-20 Thread Jan Beulich
>>> On 20.04.17 at 18:04, wrote: > On Thu, Apr 20, Andrew Cooper wrote: > >> As it currently stands, the sending side iterates from 0 to p2m_size, >> and sends every frame on the first pass. This means we get PAGE_DATA >> records linearly, in batches of 1024, or two aligned 2M superpages. > > I

Re: [Xen-devel] superpages lost after migration of HVM domU

2017-04-20 Thread Olaf Hering
On Thu, Apr 20, Andrew Cooper wrote: > As it currently stands, the sending side iterates from 0 to p2m_size, > and sends every frame on the first pass. This means we get PAGE_DATA > records linearly, in batches of 1024, or two aligned 2M superpages. Is there a way to preserve 1G pages? This 380G

Re: [Xen-devel] superpages lost after migration of HVM domU

2017-04-20 Thread Andrew Cooper
On 20/04/17 16:35, Olaf Hering wrote: > Andrew, > > with eab806a097b ("tools/libxc: x86 PV restore code") the only call of > xc_domain_populate_physmap_exact was added to the new restore code. > This call always sets order=0. The old migration code did consider > superpages, the new one does not. >

[Xen-devel] superpages lost after migration of HVM domU

2017-04-20 Thread Olaf Hering
Andrew, with eab806a097b ("tools/libxc: x86 PV restore code") the only call of xc_domain_populate_physmap_exact was added to the new restore code. This call always sets order=0. The old migration code did consider superpages, the new one does not. What is the reason for not using superpages when