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In the arm64 pmap_remove, when removing a full superpage there is no need

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to demote it to 512 pages, then remove each of these. We can just remove
the l2 map directly. This is what the intel pmaps already do.

Sponsored by:	DARPA, AFRL
This commit is contained in:
Andrew Turner 2017-07-02 08:52:08 +00:00
parent c89a3f0013
commit db7b284bd6
1 changed files with 66 additions and 11 deletions
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77
sys/arm64/arm64/pmap.c
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@ -270,8 +270,10 @@ static pt_entry_t *pmap_demote_l2_locked(pmap_t pmap, pt_entry_t *l2,
static pt_entry_t *pmap_demote_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t va);
static vm_page_t pmap_enter_quick_locked(pmap_t pmap, vm_offset_t va,
vm_page_t m, vm_prot_t prot, vm_page_t mpte, struct rwlock **lockp);
static int pmap_remove_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t sva,
pd_entry_t l1e, struct spglist *free, struct rwlock **lockp);
static int pmap_remove_l3(pmap_t pmap, pt_entry_t *l3, vm_offset_t sva,
pd_entry_t ptepde, struct spglist *free, struct rwlock **lockp);
pd_entry_t l2e, struct spglist *free, struct rwlock **lockp);
static boolean_t pmap_try_insert_pv_entry(pmap_t pmap, vm_offset_t va,
vm_page_t m, struct rwlock **lockp);
@ -280,7 +282,8 @@ static vm_page_t _pmap_alloc_l3(pmap_t pmap, vm_pindex_t ptepindex,
static void _pmap_unwire_l3(pmap_t pmap, vm_offset_t va, vm_page_t m,
struct spglist *free);
static int pmap_unuse_l3(pmap_t, vm_offset_t, pd_entry_t, struct spglist *);
static int pmap_unuse_pt(pmap_t, vm_offset_t, pd_entry_t, struct spglist *);
static __inline vm_page_t pmap_remove_pt_page(pmap_t pmap, vm_offset_t va);
/*
* These load the old table data and store the new value.
@ -1373,11 +1376,11 @@ _pmap_unwire_l3(pmap_t pmap, vm_offset_t va, vm_page_t m, struct spglist *free)
}
/*
* After removing an l3 entry, this routine is used to
* After removing a page table entry, this routine is used to
* conditionally free the page, and manage the hold/wire counts.
*/
static int
pmap_unuse_l3(pmap_t pmap, vm_offset_t va, pd_entry_t ptepde,
pmap_unuse_pt(pmap_t pmap, vm_offset_t va, pd_entry_t ptepde,
struct spglist *free)
{
vm_page_t mpte;
@ -1873,7 +1876,7 @@ reclaim_pv_chunk(pmap_t locked_pmap, struct rwlock **lockp)
}
}
pc->pc_map[field] |= 1UL << bit;
pmap_unuse_l3(pmap, va, pmap_load(pde), &free);
pmap_unuse_pt(pmap, va, pmap_load(pde), &free);
freed++;
}
}
@ -2230,6 +2233,55 @@ pmap_try_insert_pv_entry(pmap_t pmap, vm_offset_t va, vm_page_t m,
return (FALSE);
}
/*
* pmap_remove_l2: do the things to unmap a level 2 superpage in a process
*/
static int
pmap_remove_l2(pmap_t pmap, pt_entry_t *l2, vm_offset_t sva,
pd_entry_t l1e, struct spglist *free, struct rwlock **lockp)
{
struct md_page *pvh;
pt_entry_t old_l2;
vm_offset_t eva, va;
vm_page_t m, ml3;
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
KASSERT((sva & L2_OFFSET) == 0, ("pmap_remove_l2: sva is not aligned"));
old_l2 = pmap_load_clear(l2);
pmap_invalidate_range(pmap, sva, sva + L2_SIZE);
if (old_l2 & ATTR_SW_WIRED)
pmap->pm_stats.wired_count -= L2_SIZE / PAGE_SIZE;
pmap_resident_count_dec(pmap, L2_SIZE / PAGE_SIZE);
if (old_l2 & ATTR_SW_MANAGED) {
CHANGE_PV_LIST_LOCK_TO_PHYS(lockp, old_l2 & ~ATTR_MASK);
pvh = pa_to_pvh(old_l2 & ~ATTR_MASK);
pmap_pvh_free(pvh, pmap, sva);
eva = sva + L2_SIZE;
for (va = sva, m = PHYS_TO_VM_PAGE(old_l2 & ~ATTR_MASK);
va < eva; va += PAGE_SIZE, m++) {
if (pmap_page_dirty(old_l2))
vm_page_dirty(m);
if (old_l2 & ATTR_AF)
vm_page_aflag_set(m, PGA_REFERENCED);
if (TAILQ_EMPTY(&m->md.pv_list) &&
TAILQ_EMPTY(&pvh->pv_list))
vm_page_aflag_clear(m, PGA_WRITEABLE);
}
}
KASSERT(pmap != kernel_pmap,
("Attempting to remove an l2 kernel page"));
ml3 = pmap_remove_pt_page(pmap, sva);
if (ml3 != NULL) {
pmap_resident_count_dec(pmap, 1);
KASSERT(ml3->wire_count == NL3PG,
("pmap_remove_pages: l3 page wire count error"));
ml3->wire_count = 0;
pmap_add_delayed_free_list(ml3, free, FALSE);
atomic_subtract_int(&vm_cnt.v_wire_count, 1);
}
return (pmap_unuse_pt(pmap, sva, l1e, free));
}
/*
* pmap_remove_l3: do the things to unmap a page in a process
*/
@ -2262,7 +2314,7 @@ pmap_remove_l3(pmap_t pmap, pt_entry_t *l3, vm_offset_t va,
vm_page_aflag_clear(m, PGA_WRITEABLE);
}
}
return (pmap_unuse_l3(pmap, va, l2e, free));
return (pmap_unuse_pt(pmap, va, l2e, free));
}
/*
@ -2328,9 +2380,12 @@ pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
l3_paddr = pmap_load(l2);
if ((l3_paddr & ATTR_DESCR_MASK) == L2_BLOCK) {
/* TODO: Add pmap_remove_l2 */
if (pmap_demote_l2_locked(pmap, l2, sva & ~L2_OFFSET,
&lock) == NULL)
if (sva + L2_SIZE == va_next && eva >= va_next) {
pmap_remove_l2(pmap, l2, sva, pmap_load(l1),
&free, &lock);
continue;
} else if (pmap_demote_l2_locked(pmap, l2,
sva &~L2_OFFSET, &lock) == NULL)
continue;
l3_paddr = pmap_load(l2);
}
@ -2474,7 +2529,7 @@ pmap_remove_all(vm_page_t m)
*/
if (pmap_page_dirty(tpte))
vm_page_dirty(m);
pmap_unuse_l3(pmap, pv->pv_va, tpde, &free);
pmap_unuse_pt(pmap, pv->pv_va, tpde, &free);
TAILQ_REMOVE(&m->md.pv_list, pv, pv_next);
m->md.pv_gen++;
free_pv_entry(pmap, pv);
@ -3664,7 +3719,7 @@ pmap_remove_pages(pmap_t pmap)
}
break;
}
pmap_unuse_l3(pmap, pv->pv_va, pmap_load(pde),
pmap_unuse_pt(pmap, pv->pv_va, pmap_load(pde),
&free);
freed++;
}