/* $OpenBSD: uvm_anon.c,v 1.45 2016/03/29 12:04:26 chl Exp $ */ /* $NetBSD: uvm_anon.c,v 1.10 2000/11/25 06:27:59 chs Exp $ */ /* * Copyright (c) 1997 Charles D. Cranor and Washington University. * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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. */ /* * uvm_anon.c: uvm anon ops */ #include #include #include #include #include #include #include #include struct pool uvm_anon_pool; /* * allocate anons */ void uvm_anon_init(void) { pool_init(&uvm_anon_pool, sizeof(struct vm_anon), 0, 0, PR_WAITOK, "anonpl", NULL); pool_sethiwat(&uvm_anon_pool, uvmexp.free / 16); } /* * allocate an anon */ struct vm_anon * uvm_analloc(void) { struct vm_anon *anon; anon = pool_get(&uvm_anon_pool, PR_NOWAIT); if (anon) { anon->an_ref = 1; anon->an_page = NULL; anon->an_swslot = 0; } return(anon); } /* * uvm_anfree: free a single anon structure * * => caller must remove anon from its amap before calling (if it was in * an amap). * => we may lock the pageq's. */ void uvm_anfree(struct vm_anon *anon) { struct vm_page *pg; /* get page */ pg = anon->an_page; /* * if we have a resident page, we must dispose of it before freeing * the anon. */ if (pg) { /* * if page is busy then we just mark it as released (who ever * has it busy must check for this when they wake up). if the * page is not busy then we can free it now. */ if ((pg->pg_flags & PG_BUSY) != 0) { /* tell them to dump it when done */ atomic_setbits_int(&pg->pg_flags, PG_RELEASED); return; } pmap_page_protect(pg, PROT_NONE); uvm_lock_pageq(); /* lock out pagedaemon */ uvm_pagefree(pg); /* bye bye */ uvm_unlock_pageq(); /* free the daemon */ } if (pg == NULL && anon->an_swslot != 0) { /* this page is no longer only in swap. */ KASSERT(uvmexp.swpgonly > 0); uvmexp.swpgonly--; } /* free any swap resources. */ uvm_anon_dropswap(anon); /* * now that we've stripped the data areas from the anon, free the anon * itself! */ KASSERT(anon->an_page == NULL); KASSERT(anon->an_swslot == 0); pool_put(&uvm_anon_pool, anon); } /* * uvm_anon_dropswap: release any swap resources from this anon. */ void uvm_anon_dropswap(struct vm_anon *anon) { if (anon->an_swslot == 0) return; uvm_swap_free(anon->an_swslot, 1); anon->an_swslot = 0; } /* * fetch an anon's page. * * => returns TRUE if pagein was aborted due to lack of memory. */ boolean_t uvm_anon_pagein(struct vm_anon *anon) { struct vm_page *pg; int rv; rv = uvmfault_anonget(NULL, NULL, anon); switch (rv) { case VM_PAGER_OK: break; case VM_PAGER_ERROR: case VM_PAGER_REFAULT: /* * nothing more to do on errors. * VM_PAGER_REFAULT can only mean that the anon was freed, * so again there's nothing to do. */ return FALSE; default: #ifdef DIAGNOSTIC panic("anon_pagein: uvmfault_anonget -> %d", rv); #else return FALSE; #endif } /* * ok, we've got the page now. * mark it as dirty, clear its swslot and un-busy it. */ pg = anon->an_page; uvm_swap_free(anon->an_swslot, 1); anon->an_swslot = 0; atomic_clearbits_int(&pg->pg_flags, PG_CLEAN); /* deactivate the page (to put it on a page queue) */ pmap_clear_reference(pg); pmap_page_protect(pg, PROT_NONE); uvm_lock_pageq(); uvm_pagedeactivate(pg); uvm_unlock_pageq(); return FALSE; }