Module Name: src
Committed By: thorpej
Date: Sat May 9 15:13:19 UTC 2020
Modified Files:
src/sys/uvm: uvm_extern.h uvm_map.c
Log Message:
Make the uvm_voaddr structure more compact, only occupying 2 pointers
worth of space, by encoding the type in the lower bits of the object
pointer.
To generate a diff of this commit:
cvs rdiff -u -r1.225 -r1.226 src/sys/uvm/uvm_extern.h
cvs rdiff -u -r1.382 -r1.383 src/sys/uvm/uvm_map.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/uvm/uvm_extern.h
diff -u src/sys/uvm/uvm_extern.h:1.225 src/sys/uvm/uvm_extern.h:1.226
--- src/sys/uvm/uvm_extern.h:1.225 Mon Apr 27 02:47:26 2020
+++ src/sys/uvm/uvm_extern.h Sat May 9 15:13:19 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: uvm_extern.h,v 1.225 2020/04/27 02:47:26 rin Exp $ */
+/* $NetBSD: uvm_extern.h,v 1.226 2020/05/09 15:13:19 thorpej Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -613,8 +613,7 @@ extern struct vm_map *phys_map;
*
* This structure encapsulates UVM's unique virtual object address
* for an individual byte inside a pageable page. Pageable pages can
- * be owned by either a uvm_object (UVM_VOADDR_TYPE_OBJECT) or a
- * vm_anon (UVM_VOADDR_TYPE_ANON).
+ * be owned by either a uvm_object or a vm_anon.
*
* In each case, the byte offset into the owning object
* (uvm_object or vm_anon) is included in the ID, so that
@@ -631,14 +630,7 @@ extern struct vm_map *phys_map;
* use.
*/
struct uvm_voaddr {
- enum {
- UVM_VOADDR_TYPE_OBJECT = 1,
- UVM_VOADDR_TYPE_ANON = 2,
- } type;
- union {
- struct uvm_object *uobj;
- struct vm_anon *anon;
- };
+ uintptr_t object;
voff_t offset;
};
Index: src/sys/uvm/uvm_map.c
diff -u src/sys/uvm/uvm_map.c:1.382 src/sys/uvm/uvm_map.c:1.383
--- src/sys/uvm/uvm_map.c:1.382 Thu Apr 30 04:18:07 2020
+++ src/sys/uvm/uvm_map.c Sat May 9 15:13:19 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: uvm_map.c,v 1.382 2020/04/30 04:18:07 thorpej Exp $ */
+/* $NetBSD: uvm_map.c,v 1.383 2020/05/09 15:13:19 thorpej Exp $ */
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -66,7 +66,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.382 2020/04/30 04:18:07 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.383 2020/05/09 15:13:19 thorpej Exp $");
#include "opt_ddb.h"
#include "opt_pax.h"
@@ -4781,6 +4781,31 @@ uvm_map_unlock_entry(struct vm_map_entry
}
}
+#define UVM_VOADDR_TYPE_MASK 0x3UL
+#define UVM_VOADDR_TYPE_UOBJ 0x1UL
+#define UVM_VOADDR_TYPE_ANON 0x2UL
+#define UVM_VOADDR_OBJECT_MASK ~UVM_VOADDR_TYPE_MASK
+
+#define UVM_VOADDR_GET_TYPE(voa) \
+ ((voa)->object & UVM_VOADDR_TYPE_MASK)
+#define UVM_VOADDR_GET_OBJECT(voa) \
+ ((voa)->object & UVM_VOADDR_OBJECT_MASK)
+#define UVM_VOADDR_SET_OBJECT(voa, obj, type) \
+do { \
+ KASSERT(((uintptr_t)(obj) & UVM_VOADDR_TYPE_MASK) == 0); \
+ (voa)->object = ((uintptr_t)(obj)) | (type); \
+} while (/*CONSTCOND*/0)
+
+#define UVM_VOADDR_GET_UOBJ(voa) \
+ ((struct uvm_object *)UVM_VOADDR_GET_OBJECT(voa))
+#define UVM_VOADDR_SET_UOBJ(voa, uobj) \
+ UVM_VOADDR_SET_OBJECT(voa, uobj, UVM_VOADDR_TYPE_UOBJ)
+
+#define UVM_VOADDR_GET_ANON(voa) \
+ ((struct vm_anon *)UVM_VOADDR_GET_OBJECT(voa))
+#define UVM_VOADDR_SET_ANON(voa, anon) \
+ UVM_VOADDR_SET_OBJECT(voa, anon, UVM_VOADDR_TYPE_ANON)
+
/*
* uvm_voaddr_acquire: returns the virtual object address corresponding
* to the specified virtual address.
@@ -4936,8 +4961,7 @@ uvm_voaddr_acquire(struct vm_map * const
anon->an_ref++;
rw_obj_hold(anon->an_lock);
KASSERT(anon->an_ref != 0);
- voaddr->type = UVM_VOADDR_TYPE_ANON;
- voaddr->anon = anon;
+ UVM_VOADDR_SET_ANON(voaddr, anon);
voaddr->offset = va & PAGE_MASK;
result = true;
}
@@ -4950,8 +4974,7 @@ uvm_voaddr_acquire(struct vm_map * const
KASSERT(uobj != NULL);
(*uobj->pgops->pgo_reference)(uobj);
- voaddr->type = UVM_VOADDR_TYPE_OBJECT;
- voaddr->uobj = uobj;
+ UVM_VOADDR_SET_UOBJ(voaddr, uobj);
voaddr->offset = entry->offset + (va - entry->start);
result = true;
}
@@ -4961,7 +4984,9 @@ uvm_voaddr_acquire(struct vm_map * const
if (result) {
UVMHIST_LOG(maphist,
"<- done OK (type=%jd,owner=#%jx,offset=%jx)",
- voaddr->type, (uintptr_t)voaddr->uobj, voaddr->offset, 0);
+ UVM_VOADDR_GET_TYPE(voaddr),
+ UVM_VOADDR_GET_OBJECT(voaddr),
+ voaddr->offset, 0);
} else {
UVMHIST_LOG(maphist,"<- done (failed)",0,0,0,0);
}
@@ -4977,9 +5002,9 @@ void
uvm_voaddr_release(struct uvm_voaddr * const voaddr)
{
- switch (voaddr->type) {
- case UVM_VOADDR_TYPE_OBJECT: {
- struct uvm_object * const uobj = voaddr->uobj;
+ switch (UVM_VOADDR_GET_TYPE(voaddr)) {
+ case UVM_VOADDR_TYPE_UOBJ: {
+ struct uvm_object * const uobj = UVM_VOADDR_GET_UOBJ(voaddr);
KASSERT(uobj != NULL);
KASSERT(uobj->pgops->pgo_detach != NULL);
@@ -4987,7 +5012,7 @@ uvm_voaddr_release(struct uvm_voaddr * c
break;
}
case UVM_VOADDR_TYPE_ANON: {
- struct vm_anon * const anon = voaddr->anon;
+ struct vm_anon * const anon = UVM_VOADDR_GET_ANON(voaddr);
krwlock_t *lock;
KASSERT(anon != NULL);
@@ -5015,23 +5040,22 @@ int
uvm_voaddr_compare(const struct uvm_voaddr * const voaddr1,
const struct uvm_voaddr * const voaddr2)
{
+ const uintptr_t type1 = UVM_VOADDR_GET_TYPE(voaddr1);
+ const uintptr_t type2 = UVM_VOADDR_GET_TYPE(voaddr2);
- KASSERT(voaddr1->type == UVM_VOADDR_TYPE_OBJECT ||
- voaddr1->type == UVM_VOADDR_TYPE_ANON);
+ KASSERT(type1 == UVM_VOADDR_TYPE_UOBJ ||
+ type1 == UVM_VOADDR_TYPE_ANON);
- KASSERT(voaddr2->type == UVM_VOADDR_TYPE_OBJECT ||
- voaddr2->type == UVM_VOADDR_TYPE_ANON);
+ KASSERT(type2 == UVM_VOADDR_TYPE_UOBJ ||
+ type2 == UVM_VOADDR_TYPE_ANON);
- if (voaddr1->type < voaddr2->type)
+ if (type1 < type2)
return -1;
- if (voaddr1->type > voaddr2->type)
+ if (type1 > type2)
return 1;
- /* These fields are unioned together. */
- CTASSERT(offsetof(struct uvm_voaddr, uobj) ==
- offsetof(struct uvm_voaddr, anon));
- const uintptr_t addr1 = (uintptr_t)voaddr1->uobj;
- const uintptr_t addr2 = (uintptr_t)voaddr2->uobj;
+ const uintptr_t addr1 = UVM_VOADDR_GET_OBJECT(voaddr1);
+ const uintptr_t addr2 = UVM_VOADDR_GET_OBJECT(voaddr2);
if (addr1 < addr2)
return -1;
