| commit | cf0923ea295ba08ae656ef04164a43cb6553ba99 | |
| author | Jeremy Fitzhardinge <jeremy@goop.org> | |
| Mon, 26 May 2008 22:31:20 +0000 (26 23:31 +0100) | ||
| committer | Thomas Gleixner <tglx@linutronix.de> | |
| Tue, 27 May 2008 08:11:37 +0000 (27 10:11 +0200) | ||
| tree | c5c8ea1a226edcf7a29bec1953f65469a21756e5 | treesnapshot (tar.gz zip) |
| parent | 8006ec3e911f93d702e1d4a4e387e244ab434924 | commitdiff |
xen: efficiently support a holey p2m table
When using sparsemem and memory hotplug, the kernel's pseudo-physical
address space can be discontigious. Previously this was dealt with by
having the upper parts of the radix tree stubbed off. Unfortunately,
this is incompatible with save/restore, which requires a complete p2m
table.
The solution is to have a special distinguished all-invalid p2m leaf
page, which we can point all the hole areas at. This allows the tools
to see a complete p2m table, but it only costs a page for all memory
holes.
It also simplifies the code since it removes a few special cases.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When using sparsemem and memory hotplug, the kernel's pseudo-physical
address space can be discontigious. Previously this was dealt with by
having the upper parts of the radix tree stubbed off. Unfortunately,
this is incompatible with save/restore, which requires a complete p2m
table.
The solution is to have a special distinguished all-invalid p2m leaf
page, which we can point all the hole areas at. This allows the tools
to see a complete p2m table, but it only costs a page for all memory
holes.
It also simplifies the code since it removes a few special cases.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| arch/x86/xen/mmu.c | diffblobblamehistory |