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Annotation of src/sys/uvm/uvm_object.c, Revision 1.3

1.3     ! rmind       1: /*     $NetBSD: uvm_object.c,v 1.2 2006/10/12 10:13:35 yamt Exp $      */
1.1       yamt        2:
                      3: /*
                      4:  * Copyright (c) 2006 The NetBSD Foundation, Inc.
                      5:  * All rights reserved.
                      6:  *
1.3     ! rmind       7:  * This code is derived from software contributed to The NetBSD Foundation
        !             8:  * by Mindaugas Rasiukevicius.
        !             9:  *
1.1       yamt       10:  * Redistribution and use in source and binary forms, with or without
                     11:  * modification, are permitted provided that the following conditions
                     12:  * are met:
                     13:  * 1. Redistributions of source code must retain the above copyright
                     14:  *    notice, this list of conditions and the following disclaimer.
                     15:  * 2. Redistributions in binary form must reproduce the above copyright
                     16:  *    notice, this list of conditions and the following disclaimer in the
                     17:  *    documentation and/or other materials provided with the distribution.
                     18:  * 3. All advertising materials mentioning features or use of this software
                     19:  *    must display the following acknowledgement:
                     20:  *      This product includes software developed by the NetBSD
                     21:  *      Foundation, Inc. and its contributors.
                     22:  * 4. Neither the name of The NetBSD Foundation nor the names of its
                     23:  *    contributors may be used to endorse or promote products derived
                     24:  *    from this software without specific prior written permission.
                     25:  *
                     26:  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
                     27:  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
                     28:  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
                     29:  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
                     30:  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
                     31:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
                     32:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
                     33:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
                     34:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
                     35:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
                     36:  * POSSIBILITY OF SUCH DAMAGE.
                     37:  */
                     38:
                     39: /*
                     40:  * uvm_object.c: operate with memory objects
                     41:  *
                     42:  * TODO:
                     43:  *  1. Support PG_RELEASED-using objects
                     44:  *
                     45:  */
                     46:
                     47: #include <sys/cdefs.h>
1.3     ! rmind      48: __KERNEL_RCSID(0, "$NetBSD: uvm_object.c,v 1.2 2006/10/12 10:13:35 yamt Exp $");
1.1       yamt       49:
                     50: #include "opt_uvmhist.h"
                     51:
                     52: #include <sys/param.h>
                     53: #include <sys/lock.h>
                     54:
                     55: #include <uvm/uvm.h>
                     56:
                     57: /* We will fetch this page count per step */
                     58: #define        FETCH_PAGECOUNT 16
                     59:
                     60: /*
                     61:  * uobj_wirepages: wire the pages of entire uobj
                     62:  *
                     63:  * => NOTE: this function should only be used for types of objects
                     64:  *  where PG_RELEASED flag is never set (aobj objects)
                     65:  * => caller must pass page-aligned start and end values
                     66:  */
                     67:
                     68: int
                     69: uobj_wirepages(struct uvm_object *uobj, off_t start, off_t end)
                     70: {
                     71:        int i, npages, error;
                     72:        struct vm_page *pgs[FETCH_PAGECOUNT], *pg = NULL;
                     73:        off_t offset = start, left;
                     74:
                     75:        left = (end - start) >> PAGE_SHIFT;
                     76:
                     77:        simple_lock(&uobj->vmobjlock);
                     78:        while (left) {
                     79:
                     80:                npages = MIN(FETCH_PAGECOUNT, left);
                     81:
                     82:                /* Get the pages */
                     83:                memset(pgs, 0, sizeof(pgs));
                     84:                error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, 0,
                     85:                        VM_PROT_READ | VM_PROT_WRITE, UVM_ADV_SEQUENTIAL,
                     86:                        PGO_ALLPAGES | PGO_SYNCIO);
                     87:
                     88:                if (error)
                     89:                        goto error;
                     90:
                     91:                simple_lock(&uobj->vmobjlock);
                     92:                for (i = 0; i < npages; i++) {
                     93:
                     94:                        KASSERT(pgs[i] != NULL);
                     95:                        KASSERT(!(pgs[i]->flags & PG_RELEASED));
                     96:
                     97:                        /*
                     98:                         * Loan break
                     99:                         */
                    100:                        if (pgs[i]->loan_count) {
                    101:                                while (pgs[i]->loan_count) {
                    102:                                        pg = uvm_loanbreak(pgs[i]);
                    103:                                        if (!pg) {
                    104:                                                simple_unlock(&uobj->vmobjlock);
                    105:                                                uvm_wait("uobjwirepg");
                    106:                                                simple_lock(&uobj->vmobjlock);
                    107:                                                continue;
                    108:                                        }
                    109:                                }
                    110:                                pgs[i] = pg;
                    111:                        }
                    112:
                    113:                        if (pgs[i]->pqflags & PQ_AOBJ) {
                    114:                                pgs[i]->flags &= ~(PG_CLEAN);
                    115:                                uao_dropswap(uobj, i);
                    116:                        }
                    117:                }
                    118:
                    119:                /* Wire the pages */
                    120:                uvm_lock_pageq();
                    121:                for (i = 0; i < npages; i++) {
                    122:                        uvm_pagewire(pgs[i]);
                    123:                }
                    124:                uvm_unlock_pageq();
                    125:
                    126:                /* Unbusy the pages */
                    127:                uvm_page_unbusy(pgs, npages);
                    128:
                    129:                left -= npages;
                    130:                offset += npages << PAGE_SHIFT;
                    131:        }
                    132:        simple_unlock(&uobj->vmobjlock);
                    133:
                    134:        return 0;
                    135:
                    136: error:
                    137:        /* Unwire the pages which has been wired */
                    138:        uobj_unwirepages(uobj, start, offset);
                    139:
                    140:        return error;
                    141: }
                    142:
                    143: /*
                    144:  * uobj_unwirepages: unwire the pages of entire uobj
                    145:  *
                    146:  * => NOTE: this function should only be used for types of objects
                    147:  *  where PG_RELEASED flag is never set
                    148:  * => caller must pass page-aligned start and end values
                    149:  */
                    150:
                    151: void
                    152: uobj_unwirepages(struct uvm_object *uobj, off_t start, off_t end)
                    153: {
                    154:        struct vm_page *pg;
                    155:        off_t offset;
                    156:
                    157:        simple_lock(&uobj->vmobjlock);
                    158:        uvm_lock_pageq();
                    159:        for (offset = start; offset < end; offset += PAGE_SIZE) {
                    160:                pg = uvm_pagelookup(uobj, offset);
                    161:
                    162:                KASSERT(pg != NULL);
                    163:                KASSERT(!(pg->flags & PG_RELEASED));
                    164:
                    165:                uvm_pageunwire(pg);
                    166:        }
                    167:        uvm_unlock_pageq();
                    168:        simple_unlock(&uobj->vmobjlock);
                    169: }

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