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When r207410 eliminated the acquisition and release of the page queues

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lock from pmap_extract_and_hold(), it didn't take into account that
pmap_pte_quick() sometimes requires the page queues lock to be held.
This change reimplements pmap_extract_and_hold() such that it no
longer uses pmap_pte_quick(), and thus never requires the page queues
lock.

For consistency, adopt the same idiom as used by the new
implementation of pmap_extract_and_hold() in pmap_extract() and
pmap_mincore().  It also happens to make these functions shorter.

Fix a style error in pmap_pte().

Reviewed by:	kib@
This commit is contained in:
alc 2010-12-09 20:16:00 +00:00
parent 0c8713f91e
commit eca7cac32f
1 changed files with 41 additions and 62 deletions
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103
sys/i386/i386/pmap.c
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@ -1213,7 +1213,7 @@ pmap_pte(pmap_t pmap, vm_offset_t va)
}
return (PADDR2 + (i386_btop(va) & (NPTEPG - 1)));
}
return (0);
return (NULL);
}
/*
@ -1291,21 +1291,19 @@ pmap_pte_quick(pmap_t pmap, vm_offset_t va)
vm_paddr_t
pmap_extract(pmap_t pmap, vm_offset_t va)
{
pt_entry_t pte, *ptep;
vm_paddr_t rtval;
pt_entry_t *pte;
pd_entry_t pde;
rtval = 0;
PMAP_LOCK(pmap);
pde = pmap->pm_pdir[va >> PDRSHIFT];
if (pde != 0) {
if ((pde & PG_PS) != 0)
rtval = (pde & PG_PS_FRAME) | (va & PDRMASK);
else {
pte = pmap_pte(pmap, va);
rtval = (*pte & PG_FRAME) | (va & PAGE_MASK);
pmap_pte_release(pte);
}
ptep = pmap_pte(pmap, va);
pte = (ptep != NULL) ? *ptep : 0;
pmap_pte_release(ptep);
if ((pte & PG_V) != 0) {
if ((pte & PG_PS) != 0)
rtval = (pte & PG_PS_FRAME) | (va & PDRMASK);
else
rtval = (pte & PG_FRAME) | (va & PAGE_MASK);
}
PMAP_UNLOCK(pmap);
return (rtval);
@ -1321,40 +1319,30 @@ 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;
pt_entry_t pte;
pt_entry_t pte, *ptep;
vm_paddr_t locked_pa, pa;
vm_page_t m;
vm_paddr_t pa;
pa = 0;
locked_pa = 0;
m = NULL;
PMAP_LOCK(pmap);
retry:
pde = *pmap_pde(pmap, va);
if (pde != 0) {
if (pde & PG_PS) {
if ((pde & PG_RW) || (prot & VM_PROT_WRITE) == 0) {
if (vm_page_pa_tryrelock(pmap, (pde & PG_PS_FRAME) |
(va & PDRMASK), &pa))
goto retry;
m = PHYS_TO_VM_PAGE((pde & PG_PS_FRAME) |
(va & PDRMASK));
vm_page_hold(m);
}
} else {
sched_pin();
pte = *pmap_pte_quick(pmap, va);
if (pte != 0 &&
((pte & PG_RW) || (prot & VM_PROT_WRITE) == 0)) {
if (vm_page_pa_tryrelock(pmap, pte & PG_FRAME, &pa))
goto retry;
m = PHYS_TO_VM_PAGE(pte & PG_FRAME);
vm_page_hold(m);
}
sched_unpin();
}
ptep = pmap_pte(pmap, va);
pte = (ptep != NULL) ? *ptep : 0;
pmap_pte_release(ptep);
if ((pte & PG_V) != 0 &&
((pte & PG_RW) != 0 || (prot & VM_PROT_WRITE) == 0)) {
if ((pte & PG_PS) != 0) {
/* Compute the physical address of the 4KB page. */
pa = (pte & PG_PS_FRAME) | (va & PG_FRAME & PDRMASK);
} else
pa = pte & PG_FRAME;
if (vm_page_pa_tryrelock(pmap, pa, &locked_pa))
goto retry;
m = PHYS_TO_VM_PAGE(pa);
vm_page_hold(m);
PA_UNLOCK(locked_pa);
}
PA_UNLOCK_COND(pa);
PMAP_UNLOCK(pmap);
return (m);
}
@ -4991,39 +4979,30 @@ pmap_change_attr(vm_offset_t va, vm_size_t size, int mode)
int
pmap_mincore(pmap_t pmap, vm_offset_t addr, vm_paddr_t *locked_pa)
{
pd_entry_t *pdep;
pt_entry_t *ptep, pte;
vm_paddr_t pa;
int val;
PMAP_LOCK(pmap);
retry:
pdep = pmap_pde(pmap, addr);
if (*pdep != 0) {
if (*pdep & PG_PS) {
pte = *pdep;
/* Compute the physical address of the 4KB page. */
pa = ((*pdep & PG_PS_FRAME) | (addr & PDRMASK)) &
PG_FRAME;
val = MINCORE_SUPER;
} else {
ptep = pmap_pte(pmap, addr);
pte = *ptep;
pmap_pte_release(ptep);
pa = pte & PG_FRAME;
val = 0;
}
} else {
pte = 0;
pa = 0;
val = 0;
}
ptep = pmap_pte(pmap, addr);
pte = (ptep != NULL) ? *ptep : 0;
pmap_pte_release(ptep);
if ((pte & PG_V) != 0) {
val |= MINCORE_INCORE;
val = MINCORE_INCORE;
if ((pte & PG_PS) != 0) {
val |= MINCORE_SUPER;
/* Compute the physical address of the 4KB page. */
pa = (pte & PG_PS_FRAME) | (addr & PG_FRAME & PDRMASK);
} else
pa = pte & PG_FRAME;
if ((pte & (PG_M | PG_RW)) == (PG_M | PG_RW))
val |= MINCORE_MODIFIED | MINCORE_MODIFIED_OTHER;
if ((pte & PG_A) != 0)
val |= MINCORE_REFERENCED | MINCORE_REFERENCED_OTHER;
} else {
val = 0;
pa = 0;
}
if ((val & (MINCORE_MODIFIED_OTHER | MINCORE_REFERENCED_OTHER)) !=
(MINCORE_MODIFIED_OTHER | MINCORE_REFERENCED_OTHER) &&