git: 1424f65bbcb3 - main - vm_pager: Remove the default pager
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Date: Sun, 17 Jul 2022 11:24:20 UTC
The branch main has been updated by markj:
URL: https://cgit.FreeBSD.org/src/commit/?id=1424f65bbcb3283c899c356bf38ef0a9930add34
commit 1424f65bbcb3283c899c356bf38ef0a9930add34
Author: Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2022-07-16 15:30:19 +0000
Commit: Mark Johnston <markj@FreeBSD.org>
CommitDate: 2022-07-17 11:09:48 +0000
vm_pager: Remove the default pager
It's unused now. Keep the OBJ_DEFAULT identifier, but make it an alias
of OBJT_SWAP for the benefit of out-of-tree code.
Reviewed by: alc, imp, kib
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D35790
---
sys/conf/files | 1 -
sys/vm/default_pager.c | 158 -------------------------------------------------
sys/vm/vm.h | 3 +-
sys/vm/vm_pager.c | 5 +-
4 files changed, 4 insertions(+), 163 deletions(-)
diff --git a/sys/conf/files b/sys/conf/files
index 11b7e0357c79..30cd9eb7e741 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -5181,7 +5181,6 @@ ufs/ufs/ufs_lookup.c optional ffs
ufs/ufs/ufs_quota.c optional ffs
ufs/ufs/ufs_vfsops.c optional ffs
ufs/ufs/ufs_vnops.c optional ffs
-vm/default_pager.c standard
vm/device_pager.c standard
vm/phys_pager.c standard
vm/redzone.c optional DEBUG_REDZONE
diff --git a/sys/vm/default_pager.c b/sys/vm/default_pager.c
deleted file mode 100644
index d07a84f8c98e..000000000000
--- a/sys/vm/default_pager.c
+++ /dev/null
@@ -1,158 +0,0 @@
-/*-
- * SPDX-License-Identifier: BSD-4-Clause
- *
- * Copyright (c) 1995, David Greenman
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by David Greenman.
- * 4. The name of the author may not be used to endorse or promote products
- * derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD$");
-
-#include <sys/param.h>
-#include <sys/systm.h>
-#include <sys/lock.h>
-#include <sys/proc.h>
-#include <sys/resourcevar.h>
-#include <sys/rwlock.h>
-#include <sys/user.h>
-
-#include <vm/vm.h>
-#include <vm/vm_object.h>
-#include <vm/vm_page.h>
-#include <vm/vm_pager.h>
-#include <vm/swap_pager.h>
-
-static vm_object_t default_pager_alloc(void *, vm_ooffset_t, vm_prot_t,
- vm_ooffset_t, struct ucred *);
-static void default_pager_dealloc(vm_object_t);
-static int default_pager_getpages(vm_object_t, vm_page_t *, int,
- int *, int *);
-static void default_pager_putpages(vm_object_t, vm_page_t *, int,
- boolean_t, int *);
-static boolean_t default_pager_haspage(vm_object_t, vm_pindex_t, int *,
- int *);
-
-/*
- * pagerops for OBJT_DEFAULT - "default pager".
- *
- * This pager handles anonymous (no handle) swap-backed memory, just
- * like the swap pager. It allows several optimizations based on the
- * fact that no pages of a default object can be swapped out. The
- * most important optimization is in vm_fault(), where the pager is
- * never asked for a non-resident page. Instead, a freshly allocated
- * zeroed page is used.
- *
- * On the first request to page out a page from a default object, the
- * object is converted to swap pager type.
- */
-const struct pagerops defaultpagerops = {
- .pgo_kvme_type = KVME_TYPE_DEFAULT,
- .pgo_alloc = default_pager_alloc,
- .pgo_dealloc = default_pager_dealloc,
- .pgo_getpages = default_pager_getpages,
- .pgo_putpages = default_pager_putpages,
- .pgo_haspage = default_pager_haspage,
-};
-
-/*
- * Return an initialized object.
- */
-static vm_object_t
-default_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
- vm_ooffset_t offset, struct ucred *cred)
-{
- vm_object_t object;
-
- if (handle != NULL)
- panic("default_pager_alloc: handle specified");
- if (cred != NULL) {
- if (!swap_reserve_by_cred(size, cred))
- return (NULL);
- crhold(cred);
- }
- object = vm_object_allocate(OBJT_DEFAULT,
- OFF_TO_IDX(round_page(offset + size)));
- if (cred != NULL) {
- object->cred = cred;
- object->charge = size;
- }
- return (object);
-}
-
-/*
- * Deallocate resources associated with the object.
- */
-static void
-default_pager_dealloc(vm_object_t object)
-{
-
- /* Reserved swap is released by vm_object_destroy(). */
- object->type = OBJT_DEAD;
-}
-
-/*
- * Load pages from backing store.
- */
-static int
-default_pager_getpages(vm_object_t object, vm_page_t *m, int count,
- int *rbehind, int *rahead)
-{
-
- /*
- * Since an OBJT_DEFAULT object is converted to OBJT_SWAP by the first
- * call to the putpages method, this function will never be called on
- * a vm_page with assigned swap.
- */
- return (VM_PAGER_FAIL);
-}
-
-/*
- * Store pages to backing store.
- */
-static void
-default_pager_putpages(vm_object_t object, vm_page_t *m, int count,
- int flags, int *rtvals)
-{
-
- /* The swap pager will convert the object to OBJT_SWAP. */
- swappagerops.pgo_putpages(object, m, count, flags, rtvals);
-}
-
-/*
- * Tell us whether the requested (object,index) is available from the object's
- * backing store.
- */
-static boolean_t
-default_pager_haspage(vm_object_t object, vm_pindex_t pindex, int *before,
- int *after)
-{
-
- /* An OBJT_DEFAULT object has no backing store. */
- return (FALSE);
-}
diff --git a/sys/vm/vm.h b/sys/vm/vm.h
index 72b0191298d9..d0cc399dab79 100644
--- a/sys/vm/vm.h
+++ b/sys/vm/vm.h
@@ -89,8 +89,9 @@ typedef u_char vm_prot_t; /* protection codes */
#define VM_PROT_DEFAULT VM_PROT_ALL
enum obj_type {
- OBJT_DEFAULT,
+ OBJT_RESERVED = 0, /* was OBJT_DEFAULT */
OBJT_SWAP,
+ OBJT_DEFAULT = OBJT_SWAP,
OBJT_VNODE,
OBJT_DEVICE,
OBJT_PHYS,
diff --git a/sys/vm/vm_pager.c b/sys/vm/vm_pager.c
index 9b66964b8d8f..2f8afd69a1b4 100644
--- a/sys/vm/vm_pager.c
+++ b/sys/vm/vm_pager.c
@@ -166,7 +166,6 @@ static const struct pagerops deadpagerops = {
};
const struct pagerops *pagertab[16] __read_mostly = {
- [OBJT_DEFAULT] = &defaultpagerops,
[OBJT_SWAP] = &swappagerops,
[OBJT_VNODE] = &vnodepagerops,
[OBJT_DEVICE] = &devicepagerops,
@@ -190,7 +189,7 @@ vm_pager_init(void)
*/
for (i = 0; i < OBJT_FIRST_DYN; i++) {
pgops = &pagertab[i];
- if ((*pgops)->pgo_init != NULL)
+ if (*pgops != NULL && (*pgops)->pgo_init != NULL)
(*(*pgops)->pgo_init)();
}
}
@@ -402,7 +401,7 @@ vm_pager_alloc_dyn_type(struct pagerops *ops, int base_type)
mtx_lock(&pagertab_lock);
MPASS(base_type == -1 ||
- (base_type >= OBJT_DEFAULT && base_type < nitems(pagertab)));
+ (base_type >= OBJT_SWAP && base_type < nitems(pagertab)));
for (res = OBJT_FIRST_DYN; res < nitems(pagertab); res++) {
if (pagertab[res] == NULL)
break;