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Extract code for fast mapping of pte from pmap_extract_and_hold()

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into the helper function pmap_pte_ufast().

Benchmarked by:	bde
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
This commit is contained in:
Konstantin Belousov 2018-05-30 20:43:48 +00:00
parent 7883d57a72
commit c5981f69ee
1 changed files with 23 additions and 13 deletions
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36
sys/i386/i386/pmap.c
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@ -1598,6 +1598,26 @@ pmap_pte_quick3(pmap_t pmap, vm_offset_t va)
return (0);
}
static pt_entry_t
pmap_pte_ufast(pmap_t pmap, vm_offset_t va, pd_entry_t pde)
{
pt_entry_t *eh_ptep, pte, *ptep;
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
pde &= PG_FRAME;
critical_enter();
eh_ptep = (pt_entry_t *)PCPU_GET(pmap_eh_ptep);
if ((*eh_ptep & PG_FRAME) != pde) {
*eh_ptep = pde | PG_RW | PG_V | PG_A | PG_M;
invlcaddr((void *)PCPU_GET(pmap_eh_va));
}
ptep = (pt_entry_t *)PCPU_GET(pmap_eh_va) + (i386_btop(va) &
(NPTEPG - 1));
pte = *ptep;
critical_exit();
return (pte);
}
/*
* Routine: pmap_extract
* Function:
@ -1637,8 +1657,8 @@ pmap_extract(pmap_t pmap, vm_offset_t va)
vm_page_t
pmap_extract_and_hold(pmap_t pmap, vm_offset_t va, vm_prot_t prot)
{
pd_entry_t pde, newpf;
pt_entry_t *eh_ptep, pte, *ptep;
pd_entry_t pde;
pt_entry_t pte;
vm_page_t m;
vm_paddr_t pa;
@ -1658,17 +1678,7 @@ pmap_extract_and_hold(pmap_t pmap, vm_offset_t va, vm_prot_t prot)
vm_page_hold(m);
}
} else {
newpf = pde & PG_FRAME;
critical_enter();
eh_ptep = (pt_entry_t *)PCPU_GET(pmap_eh_ptep);
if ((*eh_ptep & PG_FRAME) != newpf) {
*eh_ptep = newpf | PG_RW | PG_V | PG_A | PG_M;
invlcaddr((void *)PCPU_GET(pmap_eh_va));
}
ptep = (pt_entry_t *)PCPU_GET(pmap_eh_va) +
(i386_btop(va) & (NPTEPG - 1));
pte = *ptep;
critical_exit();
pte = pmap_pte_ufast(pmap, va, pde);
if (pte != 0 &&
((pte & PG_RW) || (prot & VM_PROT_WRITE) == 0)) {
if (vm_page_pa_tryrelock(pmap, pte & PG_FRAME,