Date: Wed, 08 Aug 2012 11:10:04 -0500 From: Alan Cox <alc@rice.edu> To: mips@freebsd.org Cc: Alan Cox <alc@rice.edu> Subject: mips pmap patch Message-ID: <50228F5C.1000408@rice.edu>
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Can someone please test this patch? It applies some changes to the mips
pmap that were made a long time ago to the amd64 and i386 pmaps. In
particular, it reduces the size of a pv entry.
Briefly, the big picture is that in order to move forward with further
locking refinements to the VM system's machine-independent layer, I need
to eliminate all uses of the page queues lock from every pmap. In order
to remove the page queues lock from the mips pmap, I need to port the
new pv entry allocator from the amd64 and i386 pmaps. This patch is
preparation for that.
Alan
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filename="mips_pmap9.patch"
Index: mips/mips/pmap.c
===================================================================
--- mips/mips/pmap.c (revision 239097)
+++ mips/mips/pmap.c (working copy)
@@ -164,7 +164,8 @@ static pv_entry_t pmap_pvh_remove(struct md_page *
static __inline void pmap_changebit(vm_page_t m, int bit, boolean_t setem);
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);
-static int pmap_remove_pte(struct pmap *pmap, pt_entry_t *ptq, vm_offset_t va);
+static int pmap_remove_pte(struct pmap *pmap, pt_entry_t *ptq, vm_offset_t va,
+ pd_entry_t pde);
static void pmap_remove_page(struct pmap *pmap, vm_offset_t va);
static void pmap_remove_entry(struct pmap *pmap, vm_page_t m, vm_offset_t va);
static boolean_t pmap_try_insert_pv_entry(pmap_t pmap, vm_page_t mpte,
@@ -176,7 +177,7 @@ static int _pmap_unwire_pte_hold(pmap_t pmap, vm_o
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, vm_page_t);
+static int pmap_unuse_pt(pmap_t, vm_offset_t, pd_entry_t);
static pt_entry_t init_pte_prot(vm_offset_t va, vm_page_t m, vm_prot_t prot);
#ifdef SMP
@@ -973,8 +974,6 @@ _pmap_unwire_pte_hold(pmap_t pmap, vm_offset_t va,
pmap_unwire_pte_hold(pmap, va, pdpg);
}
#endif
- if (pmap->pm_ptphint == m)
- pmap->pm_ptphint = NULL;
/*
* If the page is finally unwired, simply free it.
@@ -989,25 +988,14 @@ _pmap_unwire_pte_hold(pmap_t pmap, vm_offset_t va,
* conditionally free the page, and manage the hold/wire counts.
*/
static int
-pmap_unuse_pt(pmap_t pmap, vm_offset_t va, vm_page_t mpte)
+pmap_unuse_pt(pmap_t pmap, vm_offset_t va, pd_entry_t pde)
{
- unsigned ptepindex;
- pd_entry_t pteva;
+ vm_page_t mpte;
if (va >= VM_MAXUSER_ADDRESS)
return (0);
-
- if (mpte == NULL) {
- ptepindex = pmap_pde_pindex(va);
- if (pmap->pm_ptphint &&
- (pmap->pm_ptphint->pindex == ptepindex)) {
- mpte = pmap->pm_ptphint;
- } else {
- pteva = *pmap_pde(pmap, va);
- mpte = PHYS_TO_VM_PAGE(MIPS_DIRECT_TO_PHYS(pteva));
- pmap->pm_ptphint = mpte;
- }
- }
+ KASSERT(pde != 0, ("pmap_unuse_pt: pde != 0"));
+ mpte = PHYS_TO_VM_PAGE(MIPS_DIRECT_TO_PHYS(pde));
return (pmap_unwire_pte_hold(pmap, va, mpte));
}
@@ -1019,7 +1007,6 @@ pmap_pinit0(pmap_t pmap)
PMAP_LOCK_INIT(pmap);
pmap->pm_segtab = kernel_segmap;
CPU_ZERO(&pmap->pm_active);
- pmap->pm_ptphint = NULL;
for (i = 0; i < MAXCPU; i++) {
pmap->pm_asid[i].asid = PMAP_ASID_RESERVED;
pmap->pm_asid[i].gen = 0;
@@ -1079,7 +1066,6 @@ pmap_pinit(pmap_t pmap)
ptdva = MIPS_PHYS_TO_DIRECT(VM_PAGE_TO_PHYS(ptdpg));
pmap->pm_segtab = (pd_entry_t *)ptdva;
CPU_ZERO(&pmap->pm_active);
- pmap->pm_ptphint = NULL;
for (i = 0; i < MAXCPU; i++) {
pmap->pm_asid[i].asid = PMAP_ASID_RESERVED;
pmap->pm_asid[i].gen = 0;
@@ -1156,17 +1142,11 @@ _pmap_allocpte(pmap_t pmap, unsigned ptepindex, in
/* Next level entry */
pde = (pd_entry_t *)*pdep;
pde[pdeindex] = (pd_entry_t)pageva;
- pmap->pm_ptphint = m;
}
#else
pmap->pm_segtab[ptepindex] = (pd_entry_t)pageva;
#endif
pmap->pm_stats.resident_count++;
-
- /*
- * Set the page table hint
- */
- pmap->pm_ptphint = m;
return (m);
}
@@ -1196,16 +1176,7 @@ retry:
* count, and activate it.
*/
if (pde != NULL && *pde != NULL) {
- /*
- * In order to get the page table page, try the hint first.
- */
- if (pmap->pm_ptphint &&
- (pmap->pm_ptphint->pindex == ptepindex)) {
- m = pmap->pm_ptphint;
- } else {
- m = PHYS_TO_VM_PAGE(MIPS_DIRECT_TO_PHYS(*pde));
- pmap->pm_ptphint = m;
- }
+ m = PHYS_TO_VM_PAGE(MIPS_DIRECT_TO_PHYS(*pde));
m->wire_count++;
} else {
/*
@@ -1351,6 +1322,7 @@ get_pv_entry(pmap_t locked_pmap)
static const struct timeval printinterval = { 60, 0 };
static struct timeval lastprint;
struct vpgqueues *vpq;
+ pd_entry_t *pde;
pt_entry_t *pte, oldpte;
pmap_t pmap;
pv_entry_t allocated_pv, next_pv, pv;
@@ -1389,8 +1361,10 @@ retry:
else if (pmap != locked_pmap && !PMAP_TRYLOCK(pmap))
continue;
pmap->pm_stats.resident_count--;
- pte = pmap_pte(pmap, va);
- KASSERT(pte != NULL, ("pte"));
+ pde = pmap_pde(pmap, va);
+ KASSERT(pde != NULL && *pde != 0,
+ ("get_pv_entry: pde"));
+ pte = pmap_pde_to_pte(pde, va);
oldpte = *pte;
if (is_kernel_pmap(pmap))
*pte = PTE_G;
@@ -1406,7 +1380,7 @@ retry:
TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist);
m->md.pv_list_count--;
TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
- pmap_unuse_pt(pmap, va, pv->pv_ptem);
+ pmap_unuse_pt(pmap, va, *pde);
if (pmap != locked_pmap)
PMAP_UNLOCK(pmap);
if (allocated_pv == NULL)
@@ -1513,7 +1487,6 @@ pmap_try_insert_pv_entry(pmap_t pmap, vm_page_t mp
pv_entry_count++;
pv->pv_va = va;
pv->pv_pmap = pmap;
- pv->pv_ptem = mpte;
TAILQ_INSERT_TAIL(&pmap->pm_pvlist, pv, pv_plist);
TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
m->md.pv_list_count++;
@@ -1526,7 +1499,8 @@ pmap_try_insert_pv_entry(pmap_t pmap, vm_page_t mp
* pmap_remove_pte: do the things to unmap a page in a process
*/
static int
-pmap_remove_pte(struct pmap *pmap, pt_entry_t *ptq, vm_offset_t va)
+pmap_remove_pte(struct pmap *pmap, pt_entry_t *ptq, vm_offset_t va,
+ pd_entry_t pde)
{
pt_entry_t oldpte;
vm_page_t m;
@@ -1561,7 +1535,7 @@ static int
pmap_remove_entry(pmap, m, va);
}
- return (pmap_unuse_pt(pmap, va, NULL));
+ return (pmap_unuse_pt(pmap, va, pde));
}
/*
@@ -1570,16 +1544,20 @@ static int
static void
pmap_remove_page(struct pmap *pmap, vm_offset_t va)
{
+ pd_entry_t *pde;
pt_entry_t *ptq;
mtx_assert(&vm_page_queue_mtx, MA_OWNED);
PMAP_LOCK_ASSERT(pmap, MA_OWNED);
- ptq = pmap_pte(pmap, va);
+ pde = pmap_pde(pmap, va);
+ if (pde == NULL || *pde == 0)
+ return;
+ ptq = pmap_pde_to_pte(pde, va);
/*
* if there is no pte for this address, just skip it!!!
*/
- if (!ptq || !pte_test(ptq, PTE_V)) {
+ if (!pte_test(ptq, PTE_V)) {
return;
}
@@ -1591,7 +1569,7 @@ pmap_remove_page(struct pmap *pmap, vm_offset_t va
/*
* get a local va for mappings for this pmap.
*/
- (void)pmap_remove_pte(pmap, ptq, va);
+ (void)pmap_remove_pte(pmap, ptq, va, *pde);
pmap_invalidate_page(pmap, va);
return;
@@ -1673,6 +1651,7 @@ void
pmap_remove_all(vm_page_t m)
{
pv_entry_t pv;
+ pd_entry_t *pde;
pt_entry_t *pte, tpte;
KASSERT((m->oflags & VPO_UNMANAGED) == 0,
@@ -1694,7 +1673,9 @@ pmap_remove_all(vm_page_t m)
pv->pv_pmap->pm_stats.resident_count--;
- pte = pmap_pte(pv->pv_pmap, pv->pv_va);
+ pde = pmap_pde(pv->pv_pmap, pv->pv_va);
+ KASSERT(pde != NULL && *pde != 0, ("pmap_remove_all: pde"));
+ pte = pmap_pde_to_pte(pde, pv->pv_va);
tpte = *pte;
if (is_kernel_pmap(pv->pv_pmap))
@@ -1719,7 +1700,7 @@ pmap_remove_all(vm_page_t m)
TAILQ_REMOVE(&pv->pv_pmap->pm_pvlist, pv, pv_plist);
TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
m->md.pv_list_count--;
- pmap_unuse_pt(pv->pv_pmap, pv->pv_va, pv->pv_ptem);
+ pmap_unuse_pt(pv->pv_pmap, pv->pv_va, *pde);
PMAP_UNLOCK(pv->pv_pmap);
free_pv_entry(pv);
}
@@ -1925,7 +1906,6 @@ pmap_enter(pmap_t pmap, vm_offset_t va, vm_prot_t
pv = get_pv_entry(pmap);
pv->pv_va = va;
pv->pv_pmap = pmap;
- pv->pv_ptem = mpte;
TAILQ_INSERT_TAIL(&pmap->pm_pvlist, pv, pv_plist);
TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
m->md.pv_list_count++;
@@ -2063,14 +2043,8 @@ pmap_enter_quick_locked(pmap_t pmap, vm_offset_t v
* increment the hold count, and activate it.
*/
if (pde && *pde != 0) {
- if (pmap->pm_ptphint &&
- (pmap->pm_ptphint->pindex == ptepindex)) {
- mpte = pmap->pm_ptphint;
- } else {
- mpte = PHYS_TO_VM_PAGE(
- MIPS_DIRECT_TO_PHYS(*pde));
- pmap->pm_ptphint = mpte;
- }
+ mpte = PHYS_TO_VM_PAGE(
+ MIPS_DIRECT_TO_PHYS(*pde));
mpte->wire_count++;
} else {
mpte = _pmap_allocpte(pmap, ptepindex,
@@ -2458,6 +2432,7 @@ pmap_page_exists_quick(pmap_t pmap, vm_page_t m)
void
pmap_remove_pages(pmap_t pmap)
{
+ pd_entry_t *pde;
pt_entry_t *pte, tpte;
pv_entry_t pv, npv;
vm_page_t m;
@@ -2470,7 +2445,9 @@ pmap_remove_pages(pmap_t pmap)
PMAP_LOCK(pmap);
for (pv = TAILQ_FIRST(&pmap->pm_pvlist); pv != NULL; pv = npv) {
- pte = pmap_pte(pv->pv_pmap, pv->pv_va);
+ pde = pmap_pde(pmap, pv->pv_va);
+ KASSERT(pde != NULL && *pde != 0, ("pmap_remove_pages: pde"));
+ pte = pmap_pde_to_pte(pde, pv->pv_va);
if (!pte_test(pte, PTE_V))
panic("pmap_remove_pages: page on pm_pvlist has no pte");
tpte = *pte;
@@ -2488,7 +2465,7 @@ pmap_remove_pages(pmap_t pmap)
KASSERT(m != NULL,
("pmap_remove_pages: bad tpte %#jx", (uintmax_t)tpte));
- pv->pv_pmap->pm_stats.resident_count--;
+ pmap->pm_stats.resident_count--;
/*
* Update the vm_page_t clean and reference bits.
@@ -2497,14 +2474,14 @@ pmap_remove_pages(pmap_t pmap)
vm_page_dirty(m);
}
npv = TAILQ_NEXT(pv, pv_plist);
- TAILQ_REMOVE(&pv->pv_pmap->pm_pvlist, pv, pv_plist);
+ TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist);
m->md.pv_list_count--;
TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
if (TAILQ_FIRST(&m->md.pv_list) == NULL) {
vm_page_aflag_clear(m, PGA_WRITEABLE);
}
- pmap_unuse_pt(pv->pv_pmap, pv->pv_va, pv->pv_ptem);
+ pmap_unuse_pt(pmap, pv->pv_va, *pde);
free_pv_entry(pv);
}
pmap_invalidate_all(pmap);
Index: mips/include/pmap.h
===================================================================
--- mips/include/pmap.h (revision 239097)
+++ mips/include/pmap.h (working copy)
@@ -90,7 +90,6 @@ struct pmap {
u_int32_t gen:ASIDGEN_BITS; /* its generation number */
} pm_asid[MAXSMPCPU];
struct pmap_statistics pm_stats; /* pmap statistics */
- struct vm_page *pm_ptphint; /* pmap ptp hint */
struct mtx pm_mtx;
};
@@ -126,7 +125,6 @@ typedef struct pv_entry {
vm_offset_t pv_va; /* virtual address for mapping */
TAILQ_ENTRY(pv_entry) pv_list;
TAILQ_ENTRY(pv_entry) pv_plist;
- vm_page_t pv_ptem; /* VM page for pte */
} *pv_entry_t;
/*
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