Dave McCracken
2009-May-22 13:35 UTC
[Xen-devel] [PATCH] Add support for superpages (hugepages) in PV domain
This patch adds the option "superpages" to the domain configuration file. If it is set, the domain is populated using 2M pages. This code does not support fallback to small pages. If the domain can not be created with 2M pages, the create will fail. The patch also includes support for saving and restoring domains with the superpage flag set. However, if a domain has freed small pages within its physical page array and then extended the array, the restore will fill in those freed pages. It will then attempt to allocate more than its memory limit and will fail. This is significant because apparently Linux does this during boot, thus a freshly booted Linux image can not be saved and restored successfully. Dave McCracken Oracle Corp. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Stefano Stabellini
2009-May-26 15:51 UTC
Re: [Xen-devel] [PATCH] Add support for superpages (hugepages) in PV domain
Unfortunately this patch forces user to specify superpages=? in their config file. Can we default the behaviour to superpages=0 instead? Dave McCracken wrote:> This patch adds the option "superpages" to the domain configuration file. If > it is set, the domain is populated using 2M pages. > > This code does not support fallback to small pages. If the domain can not be > created with 2M pages, the create will fail. > > The patch also includes support for saving and restoring domains with the > superpage flag set. However, if a domain has freed small pages within its > physical page array and then extended the array, the restore will fill in > those freed pages. It will then attempt to allocate more than its memory > limit and will fail. This is significant because apparently Linux does this > during boot, thus a freshly booted Linux image can not be saved and restored > successfully. > > Dave McCracken > Oracle Corp. > >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Dave McCracken
2009-May-26 15:54 UTC
Re: [Xen-devel] [PATCH] Add support for superpages (hugepages) in PV domain
On Tuesday 26 May 2009, Stefano Stabellini wrote:> Unfortunately this patch forces user to specify superpages=? in their > config file. > Can we default the behaviour to superpages=0 instead?Sorry. That wasn''t intentional. I''ll fix it. Dave McCracken Oracle Corp. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel