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vm_page: Stop handling VM_ALLOC_NOOBJ in vm_page_alloc_domain_after()

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This makes the allocator simpler since it can assume object != NULL.
Also modify the function to unconditionally preserve PG_ZERO, so
VM_ALLOC_ZERO is effectively ignored (and still must be implemented by
the caller for now).

Reviewed by:	alc, kib
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D32033
This commit is contained in:
Mark Johnston 2021-10-19 20:25:14 -04:00
parent 84c3922243
commit c40cf9bc62
2 changed files with 58 additions and 54 deletions
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104
sys/vm/vm_page.c
View File

@ -1963,8 +1963,6 @@ vm_page_rename(vm_page_t m, vm_object_t new_object, vm_pindex_t new_pindex)
* intends to allocate
* VM_ALLOC_NOBUSY do not exclusive busy the page
* VM_ALLOC_NODUMP do not include the page in a kernel core dump
* VM_ALLOC_NOOBJ page is not associated with an object and
* should not be exclusive busy
* VM_ALLOC_SBUSY shared busy the allocated page
* VM_ALLOC_WIRED wire the allocated page
* VM_ALLOC_ZERO prefer a zeroed page
@ -1973,8 +1971,8 @@ vm_page_t
vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req)
{
return (vm_page_alloc_after(object, pindex, req, object != NULL ?
vm_radix_lookup_le(&object->rtree, pindex) : NULL));
return (vm_page_alloc_after(object, pindex, req,
vm_radix_lookup_le(&object->rtree, pindex)));
}
vm_page_t
@ -1983,8 +1981,7 @@ vm_page_alloc_domain(vm_object_t object, vm_pindex_t pindex, int domain,
{
return (vm_page_alloc_domain_after(object, pindex, domain, req,
object != NULL ? vm_radix_lookup_le(&object->rtree, pindex) :
NULL));
vm_radix_lookup_le(&object->rtree, pindex)));
}
/*
@ -2071,24 +2068,24 @@ vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain,
{
struct vm_domain *vmd;
vm_page_t m;
int flags, pool;
int flags;
KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) &&
(object != NULL || (req & VM_ALLOC_SBUSY) == 0) &&
((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
#define VPA_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \
VM_ALLOC_NOWAIT | VM_ALLOC_NOBUSY | \
VM_ALLOC_SBUSY | VM_ALLOC_WIRED | \
VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK)
KASSERT((req & ~VPA_FLAGS) == 0,
("invalid request %#x", req));
KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)),
("inconsistent object(%p)/req(%x)", object, req));
KASSERT(object == NULL || (req & VM_ALLOC_WAITOK) == 0,
("Can't sleep and retry object insertion."));
("invalid request %#x", req));
KASSERT(mpred == NULL || mpred->pindex < pindex,
("mpred %p doesn't precede pindex 0x%jx", mpred,
(uintmax_t)pindex));
if (object != NULL)
VM_OBJECT_ASSERT_WLOCKED(object);
VM_OBJECT_ASSERT_WLOCKED(object);
flags = 0;
m = NULL;
pool = object != NULL ? VM_FREEPOOL_DEFAULT : VM_FREEPOOL_DIRECT;
again:
#if VM_NRESERVLEVEL > 0
/*
@ -2101,8 +2098,9 @@ vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain,
}
#endif
vmd = VM_DOMAIN(domain);
if (vmd->vmd_pgcache[pool].zone != NULL) {
m = uma_zalloc(vmd->vmd_pgcache[pool].zone, M_NOWAIT | M_NOVM);
if (vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone != NULL) {
m = uma_zalloc(vmd->vmd_pgcache[VM_FREEPOOL_DEFAULT].zone,
M_NOWAIT | M_NOVM);
if (m != NULL) {
flags |= PG_PCPU_CACHE;
goto found;
@ -2113,7 +2111,7 @@ vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain,
* If not, allocate it from the free page queues.
*/
vm_domain_free_lock(vmd);
m = vm_phys_alloc_pages(domain, pool, 0);
m = vm_phys_alloc_pages(domain, VM_FREEPOOL_DEFAULT, 0);
vm_domain_free_unlock(vmd);
if (m == NULL) {
vm_domain_freecnt_inc(vmd, 1);
@ -2142,15 +2140,13 @@ vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain,
/*
* Initialize the page. Only the PG_ZERO flag is inherited.
*/
if ((req & VM_ALLOC_ZERO) != 0)
flags |= (m->flags & PG_ZERO);
flags |= m->flags & PG_ZERO;
if ((req & VM_ALLOC_NODUMP) != 0)
flags |= PG_NODUMP;
m->flags = flags;
m->a.flags = 0;
m->oflags = object == NULL || (object->flags & OBJ_UNMANAGED) != 0 ?
VPO_UNMANAGED : 0;
if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_NOOBJ | VM_ALLOC_SBUSY)) == 0)
m->oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0;
if ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) == 0)
m->busy_lock = VPB_CURTHREAD_EXCLUSIVE;
else if ((req & VM_ALLOC_SBUSY) != 0)
m->busy_lock = VPB_SHARERS_WORD(1);
@ -2162,31 +2158,28 @@ vm_page_alloc_domain_after(vm_object_t object, vm_pindex_t pindex, int domain,
}
m->a.act_count = 0;
if (object != NULL) {
if (vm_page_insert_after(m, object, pindex, mpred)) {
if (req & VM_ALLOC_WIRED) {
vm_wire_sub(1);
m->ref_count = 0;
}
KASSERT(m->object == NULL, ("page %p has object", m));
m->oflags = VPO_UNMANAGED;
m->busy_lock = VPB_UNBUSIED;
/* Don't change PG_ZERO. */
vm_page_free_toq(m);
if (req & VM_ALLOC_WAITFAIL) {
VM_OBJECT_WUNLOCK(object);
vm_radix_wait();
VM_OBJECT_WLOCK(object);
}
return (NULL);
if (vm_page_insert_after(m, object, pindex, mpred)) {
if (req & VM_ALLOC_WIRED) {
vm_wire_sub(1);
m->ref_count = 0;
}
KASSERT(m->object == NULL, ("page %p has object", m));
m->oflags = VPO_UNMANAGED;
m->busy_lock = VPB_UNBUSIED;
/* Don't change PG_ZERO. */
vm_page_free_toq(m);
if (req & VM_ALLOC_WAITFAIL) {
VM_OBJECT_WUNLOCK(object);
vm_radix_wait();
VM_OBJECT_WLOCK(object);
}
return (NULL);
}
/* Ignore device objects; the pager sets "memattr" for them. */
if (object->memattr != VM_MEMATTR_DEFAULT &&
(object->flags & OBJ_FICTITIOUS) == 0)
pmap_page_set_memattr(m, object->memattr);
} else
m->pindex = pindex;
/* Ignore device objects; the pager sets "memattr" for them. */
if (object->memattr != VM_MEMATTR_DEFAULT &&
(object->flags & OBJ_FICTITIOUS) == 0)
pmap_page_set_memattr(m, object->memattr);
return (m);
}
@ -2405,9 +2398,12 @@ _vm_page_alloc_noobj_domain(int domain, const int freelist, int req)
vm_page_t m;
int flags;
KASSERT((req & (VM_ALLOC_SBUSY | VM_ALLOC_IGN_SBUSY |
VM_ALLOC_NOOBJ)) == 0,
("%s: invalid req %#x", __func__, req));
#define VPAN_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL | \
VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | \
VM_ALLOC_NOBUSY | VM_ALLOC_WIRED | \
VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK)
KASSERT((req & ~VPAN_FLAGS) == 0,
("invalid request %#x", req));
flags = (req & VM_ALLOC_NODUMP) != 0 ? PG_NODUMP : 0;
vmd = VM_DOMAIN(domain);
@ -2443,7 +2439,9 @@ _vm_page_alloc_noobj_domain(int domain, const int freelist, int req)
vm_page_dequeue(m);
vm_page_alloc_check(m);
/* Consumers should not rely on a useful default pindex value. */
/*
* Consumers should not rely on a useful default pindex value.
*/
m->pindex = 0xdeadc0dedeadc0de;
m->flags = (m->flags & PG_ZERO) | flags;
m->a.flags = 0;
@ -4508,7 +4506,7 @@ vm_page_grab_pflags(int allocflags)
pflags = allocflags &
~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL |
VM_ALLOC_NOBUSY);
VM_ALLOC_NOBUSY | VM_ALLOC_IGN_SBUSY);
if ((allocflags & VM_ALLOC_NOWAIT) == 0)
pflags |= VM_ALLOC_WAITFAIL;
if ((allocflags & VM_ALLOC_IGN_SBUSY) != 0)
@ -4681,7 +4679,7 @@ vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int al
("vm_page_grab_valid: Invalid flags 0x%X", allocflags));
VM_OBJECT_ASSERT_WLOCKED(object);
pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY |
VM_ALLOC_WIRED);
VM_ALLOC_WIRED | VM_ALLOC_IGN_SBUSY);
pflags |= VM_ALLOC_WAITFAIL;
retrylookup:

8
sys/vm/vm_page.h
View File

@ -549,8 +549,14 @@ vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa);
#define VM_ALLOC_NODUMP 0x2000 /* (ag) don't include in dump */
#define VM_ALLOC_SBUSY 0x4000 /* (acgp) Shared busy the page */
#define VM_ALLOC_NOWAIT 0x8000 /* (acgnp) Do not sleep */
#define VM_ALLOC_COUNT_MAX 0xffff
#define VM_ALLOC_COUNT_SHIFT 16
#define VM_ALLOC_COUNT(count) ((count) << VM_ALLOC_COUNT_SHIFT)
#define VM_ALLOC_COUNT_MASK (VM_ALLOC_COUNT(VM_ALLOC_COUNT_MAX))
#define VM_ALLOC_COUNT(count) ({ \
KASSERT((count) <= VM_ALLOC_COUNT_MAX, \
("%s: invalid VM_ALLOC_COUNT value", __func__)); \
(count) << VM_ALLOC_COUNT_SHIFT; \
})
#ifdef M_NOWAIT
static inline int