amd64 pmap: only calculate page table page when needed.

Noted by:	alc
Reviewed by:	alc, markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D26499
This commit is contained in:
Konstantin Belousov 2020-09-21 15:53:41 +00:00
parent b1365a26e9
commit 6d4b6bd3ce

View File

@ -6525,12 +6525,13 @@ pmap_enter_largepage(pmap_t pmap, vm_offset_t va, pt_entry_t newpte, int flags,
origpte = *pdpe;
MPASS(origpte == 0);
} else {
mp = PHYS_TO_VM_PAGE(*pml4e & PG_FRAME);
pdpe = pmap_pdpe(pmap, va);
KASSERT(pdpe != NULL, ("va %#lx lost pdpe", va));
origpte = *pdpe;
if ((origpte & PG_V) == 0)
if ((origpte & PG_V) == 0) {
mp = PHYS_TO_VM_PAGE(*pml4e & PG_FRAME);
mp->ref_count++;
}
}
KASSERT((origpte & PG_V) == 0 || ((origpte & PG_PS) != 0 &&
(origpte & PG_FRAME) == (pten & PG_FRAME)),
@ -6563,10 +6564,11 @@ pmap_enter_largepage(pmap_t pmap, vm_offset_t va, pt_entry_t newpte, int flags,
} else {
pdpe = pmap_pdpe(pmap, va);
MPASS(pdpe != NULL && (*pdpe & PG_V) != 0);
mp = PHYS_TO_VM_PAGE(*pdpe & PG_FRAME);
origpte = *pde;
if ((origpte & PG_V) == 0)
if ((origpte & PG_V) == 0) {
mp = PHYS_TO_VM_PAGE(*pdpe & PG_FRAME);
mp->ref_count++;
}
}
KASSERT((origpte & PG_V) == 0 || ((origpte & PG_PS) != 0 &&
(origpte & PG_FRAME) == (pten & PG_FRAME)),