Messages in this thread | | | Date | Wed, 26 May 2010 13:04:26 +0300 | From | Avi Kivity <> | Subject | Re: [RESEND PATCH 3/3 V2] kvm mmu: reduce 50% memory usage |
| |
On 05/26/2010 11:49 AM, Lai Jiangshan wrote: > I think users will enable tdp when their hardwares support ept or npt. > This patch can reduce about 50% kvm mmu memory usage for they. > > This simple patch use the fact that: > > When sp->role.direct is set, sp->gfns does not contain any essential > information, leaf sptes reachable from this sp are for a continuate > guest physical memory range(a linear range). > So sp->gfns[i](if it was set) equals to sp->gfn + i. (PT_PAGE_TABLE_LEVEL) > Obviously, it is not essential information, we can calculate it when need. > > It means we don't need sp->gfns when sp->role.direct=1, > Thus we can save one page usage for every kvm_mmu_page. > > Note: > Access to sp->gfns must be wrapped by kvm_mmu_page_get_gfn() > or kvm_mmu_page_set_gfn(). > It is only exposed in FNAME(sync_page). > >
Applied, thanks.
-- error compiling committee.c: too many arguments to function
| |