svn commit: r320571 - head/sys/arm64/arm64
Andrew Turner
andrew at FreeBSD.org
Sun Jul 2 08:52:10 UTC 2017
Author: andrew
Date: Sun Jul 2 08:52:08 2017
New Revision: 320571
URL: https://svnweb.freebsd.org/changeset/base/320571
Log:
In the arm64 pmap_remove, when removing a full superpage there is no need
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
Modified:
head/sys/arm64/arm64/pmap.c
Modified: head/sys/arm64/arm64/pmap.c
==============================================================================
--- head/sys/arm64/arm64/pmap.c Sun Jul 2 05:40:22 2017 (r320570)
+++ head/sys/arm64/arm64/pmap.c Sun Jul 2 08:52:08 2017 (r320571)
@@ -270,8 +270,10 @@ static pt_entry_t *pmap_demote_l2_locked(pmap_t pmap,
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
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
}
/*
- * 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 **l
}
}
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++;
}
}
@@ -2231,6 +2234,55 @@ pmap_try_insert_pv_entry(pmap_t pmap, vm_offset_t va,
}
/*
+ * 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
*/
static int
@@ -2262,7 +2314,7 @@ pmap_remove_l3(pmap_t pmap, pt_entry_t *l3, vm_offset_
vm_page_aflag_clear(m, PGA_WRITEABLE);
}
}
- return (pmap_unuse_l3(pmap, va, l2e, free));
+ return (pmap_unuse_pt(pmap, va, l2e, free));
}
/*
@@ -2328,10 +2380,13 @@ pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t
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 @@ retry:
*/
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++;
}
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