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Retire PV_TABLE_MOD. When we destroy or write protect a dirty mapping,

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we call vm_page_dirty().  Maintaining the PV_TABLE_MOD flag, in addition,
serves no useful purpose.
This commit is contained in:
Alan Cox 2012-08-25 16:55:38 +00:00
parent 15e154df01
commit 648b050d7d
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=239681
2 changed files with 12 additions and 22 deletions
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1
sys/mips/include/pmap.h
View File

@ -73,7 +73,6 @@ struct md_page {
TAILQ_HEAD(, pv_entry) pv_list;
};
#define PV_TABLE_MOD 0x01 /* modified */
#define PV_TABLE_REF 0x02 /* referenced */
#define ASID_BITS 8

33
sys/mips/mips/pmap.c
View File

@ -195,7 +195,7 @@ static int _pmap_unwire_pte_hold(pmap_t pmap, vm_offset_t va, vm_page_t m);
static vm_page_t pmap_allocpte(pmap_t pmap, vm_offset_t va, int flags);
static vm_page_t _pmap_allocpte(pmap_t pmap, unsigned ptepindex, int flags);
static int pmap_unuse_pt(pmap_t, vm_offset_t, pd_entry_t);
static pt_entry_t init_pte_prot(vm_page_t m, vm_prot_t prot);
static pt_entry_t init_pte_prot(vm_page_t m, vm_prot_t access, vm_prot_t prot);
#ifdef SMP
static void pmap_invalidate_page_action(void *arg);
@ -1431,12 +1431,10 @@ pmap_pv_reclaim(pmap_t locked_pmap)
vm_page_dirty(m);
if (m->md.pv_flags & PV_TABLE_REF)
vm_page_aflag_set(m, PGA_REFERENCED);
m->md.pv_flags &= ~PV_TABLE_REF;
TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
if (TAILQ_EMPTY(&m->md.pv_list)) {
if (TAILQ_EMPTY(&m->md.pv_list))
vm_page_aflag_clear(m, PGA_WRITEABLE);
m->md.pv_flags &= ~(PV_TABLE_REF |
PV_TABLE_MOD);
}
pc->pc_map[field] |= 1UL << bit;
pmap_unuse_pt(pmap, va, *pde);
freed++;
@ -1705,7 +1703,7 @@ pmap_remove_pte(struct pmap *pmap, pt_entry_t *ptq, vm_offset_t va,
}
if (m->md.pv_flags & PV_TABLE_REF)
vm_page_aflag_set(m, PGA_REFERENCED);
m->md.pv_flags &= ~(PV_TABLE_REF | PV_TABLE_MOD);
m->md.pv_flags &= ~PV_TABLE_REF;
pmap_remove_entry(pmap, m, va);
}
@ -1877,7 +1875,7 @@ pmap_remove_all(vm_page_t m)
}
vm_page_aflag_clear(m, PGA_WRITEABLE);
m->md.pv_flags &= ~(PV_TABLE_REF | PV_TABLE_MOD);
m->md.pv_flags &= ~PV_TABLE_REF;
rw_wunlock(&pvh_global_lock);
}
@ -1936,7 +1934,6 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
if (page_is_managed(pa) && pte_test(&pbits, PTE_D)) {
m = PHYS_TO_VM_PAGE(pa);
vm_page_dirty(m);
m->md.pv_flags &= ~PV_TABLE_MOD;
}
pte_clear(&pbits, PTE_D);
pte_set(&pbits, PTE_RO);
@ -2082,8 +2079,8 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_prot_t access, vm_page_t m,
validate:
if ((access & VM_PROT_WRITE) != 0)
m->md.pv_flags |= PV_TABLE_MOD | PV_TABLE_REF;
rw = init_pte_prot(m, prot);
m->md.pv_flags |= PV_TABLE_REF;
rw = init_pte_prot(m, access, prot);
#ifdef PMAP_DEBUG
printf("pmap_enter: va: %p -> pa: %p\n", (void *)va, (void *)pa);
@ -2114,8 +2111,7 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_prot_t access, vm_page_t m,
if (page_is_managed(opa) && (opa != pa)) {
if (om->md.pv_flags & PV_TABLE_REF)
vm_page_aflag_set(om, PGA_REFERENCED);
om->md.pv_flags &=
~(PV_TABLE_REF | PV_TABLE_MOD);
om->md.pv_flags &= ~PV_TABLE_REF;
}
if (pte_test(&origpte, PTE_D)) {
KASSERT(!pte_test(&origpte, PTE_RO),
@ -2751,7 +2747,6 @@ pmap_remove_write(vm_page_t m)
if (pte_test(&pbits, PTE_D)) {
pte_clear(&pbits, PTE_D);
vm_page_dirty(m);
m->md.pv_flags &= ~PV_TABLE_MOD;
}
pte_set(&pbits, PTE_RO);
if (pbits != *pte) {
@ -2808,10 +2803,7 @@ pmap_is_modified(vm_page_t m)
(m->aflags & PGA_WRITEABLE) == 0)
return (FALSE);
rw_wlock(&pvh_global_lock);
if (m->md.pv_flags & PV_TABLE_MOD)
rv = TRUE;
else
rv = pmap_testbit(m, PTE_D);
rv = pmap_testbit(m, PTE_D);
rw_wunlock(&pvh_global_lock);
return (rv);
}
@ -2876,7 +2868,6 @@ pmap_clear_modify(vm_page_t m)
}
PMAP_UNLOCK(pmap);
}
m->md.pv_flags &= ~PV_TABLE_MOD;
rw_wunlock(&pvh_global_lock);
}
@ -3259,14 +3250,14 @@ page_is_managed(vm_paddr_t pa)
}
static pt_entry_t
init_pte_prot(vm_page_t m, vm_prot_t prot)
init_pte_prot(vm_page_t m, vm_prot_t access, vm_prot_t prot)
{
pt_entry_t rw;
if (!(prot & VM_PROT_WRITE))
rw = PTE_V | PTE_RO;
else if ((m->oflags & VPO_UNMANAGED) == 0) {
if ((m->md.pv_flags & PV_TABLE_MOD) != 0)
if ((access & VM_PROT_WRITE) != 0)
rw = PTE_V | PTE_D;
else
rw = PTE_V;
@ -3318,7 +3309,7 @@ pmap_emulate_modified(pmap_t pmap, vm_offset_t va)
if (!page_is_managed(pa))
panic("pmap_emulate_modified: unmanaged page");
m = PHYS_TO_VM_PAGE(pa);
m->md.pv_flags |= (PV_TABLE_REF | PV_TABLE_MOD);
m->md.pv_flags |= PV_TABLE_REF;
PMAP_UNLOCK(pmap);
return (0);
}