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;