svn commit: r365488 - head/sys/vm
Konstantin Belousov
kib at FreeBSD.org
Wed Sep 9 00:00:44 UTC 2020
Author: kib
Date: Wed Sep 9 00:00:43 2020
New Revision: 365488
URL: https://svnweb.freebsd.org/changeset/base/365488
Log:
Allow consumer to customize physical pager.
Add support for user-supplied callbacks into phys pager operations,
providing custom getpages(), haspage(), and populate() methods
implementations. Pager stores user data ptr/val in the object to
provide context.
Add phys_pager_allocate() helper that takes user ops table as one of
the arguments.
Current code for these methods is moved to the 'default' ops table,
assigned automatically when vm_pager_alloc() is used.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D24652
Modified:
head/sys/vm/phys_pager.c
head/sys/vm/vm_object.c
head/sys/vm/vm_object.h
head/sys/vm/vm_pager.h
Modified: head/sys/vm/phys_pager.c
==============================================================================
--- head/sys/vm/phys_pager.c Tue Sep 8 23:48:49 2020 (r365487)
+++ head/sys/vm/phys_pager.c Wed Sep 9 00:00:43 2020 (r365488)
@@ -51,6 +51,20 @@ static struct pagerlst phys_pager_object_list;
/* protect access to phys_pager_object_list */
static struct mtx phys_pager_mtx;
+static int default_phys_pager_getpages(vm_object_t object, vm_page_t *m,
+ int count, int *rbehind, int *rahead);
+static int default_phys_pager_populate(vm_object_t object, vm_pindex_t pidx,
+ int fault_type, vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last);
+static boolean_t default_phys_pager_haspage(vm_object_t object,
+ vm_pindex_t pindex, int *before, int *after);
+struct phys_pager_ops default_phys_pg_ops = {
+ .phys_pg_getpages = default_phys_pager_getpages,
+ .phys_pg_populate = default_phys_pager_populate,
+ .phys_pg_haspage = default_phys_pager_haspage,
+ .phys_pg_ctor = NULL,
+ .phys_pg_dtor = NULL,
+};
+
static void
phys_pager_init(void)
{
@@ -59,12 +73,13 @@ phys_pager_init(void)
mtx_init(&phys_pager_mtx, "phys_pager list", NULL, MTX_DEF);
}
-static vm_object_t
-phys_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
- vm_ooffset_t foff, struct ucred *cred)
+vm_object_t
+phys_pager_allocate(void *handle, struct phys_pager_ops *ops, void *data,
+ vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff, struct ucred *cred)
{
vm_object_t object, object1;
vm_pindex_t pindex;
+ bool init;
/*
* Offset should be page aligned.
@@ -73,6 +88,7 @@ phys_pager_alloc(void *handle, vm_ooffset_t size, vm_p
return (NULL);
pindex = OFF_TO_IDX(foff + PAGE_MASK + size);
+ init = true;
if (handle != NULL) {
mtx_lock(&phys_pager_mtx);
@@ -97,11 +113,15 @@ phys_pager_alloc(void *handle, vm_ooffset_t size, vm_p
*/
if (pindex > object->size)
object->size = pindex;
+ init = false;
} else {
object = object1;
object1 = NULL;
object->handle = handle;
- vm_object_set_flag(object, OBJ_POPULATE);
+ object->un_pager.phys.ops = ops;
+ object->un_pager.phys.data_ptr = data;
+ if (ops->phys_pg_populate != NULL)
+ vm_object_set_flag(object, OBJ_POPULATE);
TAILQ_INSERT_TAIL(&phys_pager_object_list,
object, pager_object_list);
}
@@ -113,12 +133,25 @@ phys_pager_alloc(void *handle, vm_ooffset_t size, vm_p
vm_object_deallocate(object1);
} else {
object = vm_object_allocate(OBJT_PHYS, pindex);
- vm_object_set_flag(object, OBJ_POPULATE);
+ object->un_pager.phys.ops = ops;
+ object->un_pager.phys.data_ptr = data;
+ if (ops->phys_pg_populate != NULL)
+ vm_object_set_flag(object, OBJ_POPULATE);
}
+ if (init && ops->phys_pg_ctor != NULL)
+ ops->phys_pg_ctor(object, prot, foff, cred);
return (object);
}
+static vm_object_t
+phys_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
+ vm_ooffset_t foff, struct ucred *ucred)
+{
+ return (phys_pager_allocate(handle, &default_phys_pg_ops, NULL,
+ size, prot, foff, ucred));
+}
+
static void
phys_pager_dealloc(vm_object_t object)
{
@@ -130,16 +163,18 @@ phys_pager_dealloc(vm_object_t object)
mtx_unlock(&phys_pager_mtx);
VM_OBJECT_WLOCK(object);
}
- object->handle = NULL;
object->type = OBJT_DEAD;
+ if (object->un_pager.phys.ops->phys_pg_dtor != NULL)
+ object->un_pager.phys.ops->phys_pg_dtor(object);
+ object->handle = NULL;
}
/*
* Fill as many pages as vm_fault has allocated for us.
*/
static int
-phys_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind,
- int *rahead)
+default_phys_pager_getpages(vm_object_t object, vm_page_t *m, int count,
+ int *rbehind, int *rahead)
{
int i;
@@ -161,6 +196,14 @@ phys_pager_getpages(vm_object_t object, vm_page_t *m,
return (VM_PAGER_OK);
}
+static int
+phys_pager_getpages(vm_object_t object, vm_page_t *m, int count, int *rbehind,
+ int *rahead)
+{
+ return (object->un_pager.phys.ops->phys_pg_getpages(object, m,
+ count, rbehind, rahead));
+}
+
/*
* Implement a pretty aggressive clustered getpages strategy. Hint that
* everything in an entire 4MB window should be prefaulted at once.
@@ -185,7 +228,7 @@ SYSCTL_INT(_vm, OID_AUTO, phys_pager_cluster, CTLFLAG_
#define PHYSALLOC 16
static int
-phys_pager_populate(vm_object_t object, vm_pindex_t pidx,
+default_phys_pager_populate(vm_object_t object, vm_pindex_t pidx,
int fault_type __unused, vm_prot_t max_prot __unused, vm_pindex_t *first,
vm_pindex_t *last)
{
@@ -216,6 +259,14 @@ phys_pager_populate(vm_object_t object, vm_pindex_t pi
return (VM_PAGER_OK);
}
+static int
+phys_pager_populate(vm_object_t object, vm_pindex_t pidx, int fault_type,
+ vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last)
+{
+ return (object->un_pager.phys.ops->phys_pg_populate(object, pidx,
+ fault_type, max_prot, first, last));
+}
+
static void
phys_pager_putpages(vm_object_t object, vm_page_t *m, int count, boolean_t sync,
int *rtvals)
@@ -225,7 +276,7 @@ phys_pager_putpages(vm_object_t object, vm_page_t *m,
}
static boolean_t
-phys_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
+default_phys_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
int *after)
{
vm_pindex_t base, end;
@@ -237,6 +288,14 @@ phys_pager_haspage(vm_object_t object, vm_pindex_t pin
if (after != NULL)
*after = end - pindex;
return (TRUE);
+}
+
+static boolean_t
+phys_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
+ int *after)
+{
+ return (object->un_pager.phys.ops->phys_pg_haspage(object, pindex,
+ before, after));
}
struct pagerops physpagerops = {
Modified: head/sys/vm/vm_object.c
==============================================================================
--- head/sys/vm/vm_object.c Tue Sep 8 23:48:49 2020 (r365487)
+++ head/sys/vm/vm_object.c Wed Sep 9 00:00:43 2020 (r365488)
@@ -286,6 +286,7 @@ vm_object_init(void)
kernel_object->flags |= OBJ_COLORED;
kernel_object->pg_color = (u_short)atop(VM_MIN_KERNEL_ADDRESS);
#endif
+ kernel_object->un_pager.phys.ops = &default_phys_pg_ops;
/*
* The lock portion of struct vm_object must be type stable due
Modified: head/sys/vm/vm_object.h
==============================================================================
--- head/sys/vm/vm_object.h Tue Sep 8 23:48:49 2020 (r365487)
+++ head/sys/vm/vm_object.h Wed Sep 9 00:00:43 2020 (r365488)
@@ -173,6 +173,17 @@ struct vm_object {
struct pctrie swp_blks;
vm_ooffset_t writemappings;
} swp;
+
+ /*
+ * Phys pager
+ */
+ struct {
+ struct phys_pager_ops *ops;
+ union {
+ void *data_ptr;
+ uintptr_t data_val;
+ };
+ } phys;
} un_pager;
struct ucred *cred;
vm_ooffset_t charge;
Modified: head/sys/vm/vm_pager.h
==============================================================================
--- head/sys/vm/vm_pager.h Tue Sep 8 23:48:49 2020 (r365487)
+++ head/sys/vm/vm_pager.h Wed Sep 9 00:00:43 2020 (r365488)
@@ -227,5 +227,22 @@ vm_object_t cdev_pager_allocate(void *handle, enum obj
vm_object_t cdev_pager_lookup(void *handle);
void cdev_pager_free_page(vm_object_t object, vm_page_t m);
+struct phys_pager_ops {
+ int (*phys_pg_getpages)(vm_object_t vm_obj, vm_page_t *m, int count,
+ int *rbehind, int *rahead);
+ int (*phys_pg_populate)(vm_object_t vm_obj, vm_pindex_t pidx,
+ int fault_type, vm_prot_t max_prot, vm_pindex_t *first,
+ vm_pindex_t *last);
+ boolean_t (*phys_pg_haspage)(vm_object_t obj, vm_pindex_t pindex,
+ int *before, int *after);
+ void (*phys_pg_ctor)(vm_object_t vm_obj, vm_prot_t prot,
+ vm_ooffset_t foff, struct ucred *cred);
+ void (*phys_pg_dtor)(vm_object_t vm_obj);
+};
+extern struct phys_pager_ops default_phys_pg_ops;
+vm_object_t phys_pager_allocate(void *handle, struct phys_pager_ops *ops,
+ void *data, vm_ooffset_t size, vm_prot_t prot, vm_ooffset_t foff,
+ struct ucred *cred);
+
#endif /* _KERNEL */
#endif /* _VM_PAGER_ */
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