/* $NetBSD: uvm_page.c,v 1.103 2005/05/11 13:02:26 yamt Exp $ */ /* * Copyright (c) 1997 Charles D. Cranor and Washington University. * Copyright (c) 1991, 1993, The Regents of the University of California. * * All rights reserved. * * This code is derived from software contributed to Berkeley by * The Mach Operating System project at Carnegie-Mellon University. * * 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 Charles D. Cranor, * Washington University, the University of California, Berkeley and * its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. * * @(#)vm_page.c 8.3 (Berkeley) 3/21/94 * from: Id: uvm_page.c,v 1.1.2.18 1998/02/06 05:24:42 chs Exp * * * Copyright (c) 1987, 1990 Carnegie-Mellon University. * All rights reserved. * * Permission to use, copy, modify and distribute this software and * its documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. */ /* * uvm_page.c: page ops. */ #include __KERNEL_RCSID(0, "$NetBSD: uvm_page.c,v 1.103 2005/05/11 13:02:26 yamt Exp $"); #include "opt_uvmhist.h" #include #include #include #include #include #include #include #define UVM_PAGE /* pull in uvm_page.h functions */ #include /* * global vars... XXXCDC: move to uvm. structure. */ /* * physical memory config is stored in vm_physmem. */ struct vm_physseg vm_physmem[VM_PHYSSEG_MAX]; /* XXXCDC: uvm.physmem */ int vm_nphysseg = 0; /* XXXCDC: uvm.nphysseg */ /* * Some supported CPUs in a given architecture don't support all * of the things necessary to do idle page zero'ing efficiently. * We therefore provide a way to disable it from machdep code here. */ /* * XXX disabled until we can find a way to do this without causing * problems for either CPU caches or DMA latency. */ boolean_t vm_page_zero_enable = FALSE; /* * local variables */ /* * these variables record the values returned by vm_page_bootstrap, * for debugging purposes. The implementation of uvm_pageboot_alloc * and pmap_startup here also uses them internally. */ static vaddr_t virtual_space_start; static vaddr_t virtual_space_end; /* * we use a hash table with only one bucket during bootup. we will * later rehash (resize) the hash table once the allocator is ready. * we static allocate the one bootstrap bucket below... */ static struct pglist uvm_bootbucket; /* * we allocate an initial number of page colors in uvm_page_init(), * and remember them. We may re-color pages as cache sizes are * discovered during the autoconfiguration phase. But we can never * free the initial set of buckets, since they are allocated using * uvm_pageboot_alloc(). */ static boolean_t have_recolored_pages /* = FALSE */; MALLOC_DEFINE(M_VMPAGE, "VM page", "VM page"); #ifdef DEBUG vaddr_t uvm_zerocheckkva; #endif /* DEBUG */ /* * local prototypes */ static void uvm_pageinsert(struct vm_page *); static void uvm_pageinsert_after(struct vm_page *, struct vm_page *); static void uvm_pageremove(struct vm_page *); /* * inline functions */ /* * uvm_pageinsert: insert a page in the object and the hash table * uvm_pageinsert_after: insert a page into the specified place in listq * * => caller must lock object * => caller must lock page queues * => call should have already set pg's object and offset pointers * and bumped the version counter */ __inline static void uvm_pageinsert_after(pg, where) struct vm_page *pg; struct vm_page *where; { struct pglist *buck; struct uvm_object *uobj = pg->uobject; KASSERT((pg->flags & PG_TABLED) == 0); KASSERT(where == NULL || (where->flags & PG_TABLED)); KASSERT(where == NULL || (where->uobject == uobj)); buck = &uvm.page_hash[uvm_pagehash(uobj, pg->offset)]; simple_lock(&uvm.hashlock); TAILQ_INSERT_TAIL(buck, pg, hashq); simple_unlock(&uvm.hashlock); if (UVM_OBJ_IS_VNODE(uobj)) { if (uobj->uo_npages == 0) { struct vnode *vp = (struct vnode *)uobj; vholdl(vp); } if (UVM_OBJ_IS_VTEXT(uobj)) { uvmexp.execpages++; } else { uvmexp.filepages++; } } else if (UVM_OBJ_IS_AOBJ(uobj)) { uvmexp.anonpages++; } if (where) TAILQ_INSERT_AFTER(&uobj->memq, where, pg, listq); else TAILQ_INSERT_TAIL(&uobj->memq, pg, listq); pg->flags |= PG_TABLED; uobj->uo_npages++; } __inline static void uvm_pageinsert(pg) struct vm_page *pg; { uvm_pageinsert_after(pg, NULL); } /* * uvm_page_remove: remove page from object and hash * * => caller must lock object * => caller must lock page queues */ static __inline void uvm_pageremove(pg) struct vm_page *pg; { struct pglist *buck; struct uvm_object *uobj = pg->uobject; KASSERT(pg->flags & PG_TABLED); buck = &uvm.page_hash[uvm_pagehash(uobj, pg->offset)]; simple_lock(&uvm.hashlock); TAILQ_REMOVE(buck, pg, hashq); simple_unlock(&uvm.hashlock); if (UVM_OBJ_IS_VNODE(uobj)) { if (uobj->uo_npages == 1) { struct vnode *vp = (struct vnode *)uobj; holdrelel(vp); } if (UVM_OBJ_IS_VTEXT(uobj)) { uvmexp.execpages--; } else { uvmexp.filepages--; } } else if (UVM_OBJ_IS_AOBJ(uobj)) { uvmexp.anonpages--; } /* object should be locked */ uobj->uo_npages--; TAILQ_REMOVE(&uobj->memq, pg, listq); pg->flags &= ~PG_TABLED; pg->uobject = NULL; } static void uvm_page_init_buckets(struct pgfreelist *pgfl) { int color, i; for (color = 0; color < uvmexp.ncolors; color++) { for (i = 0; i < PGFL_NQUEUES; i++) { TAILQ_INIT(&pgfl->pgfl_buckets[color].pgfl_queues[i]); } } } /* * uvm_page_init: init the page system. called from uvm_init(). * * => we return the range of kernel virtual memory in kvm_startp/kvm_endp */ void uvm_page_init(kvm_startp, kvm_endp) vaddr_t *kvm_startp, *kvm_endp; { vsize_t freepages, pagecount, bucketcount, n; struct pgflbucket *bucketarray; struct vm_page *pagearray; int lcv; u_int i; paddr_t paddr; /* * init the page queues and page queue locks, except the free * list; we allocate that later (with the initial vm_page * structures). */ TAILQ_INIT(&uvm.page_active); TAILQ_INIT(&uvm.page_inactive); simple_lock_init(&uvm.pageqlock); simple_lock_init(&uvm.fpageqlock); /* * init the => hash table. for now * we just have one bucket (the bootstrap bucket). later on we * will allocate new buckets as we dynamically resize the hash table. */ uvm.page_nhash = 1; /* 1 bucket */ uvm.page_hashmask = 0; /* mask for hash function */ uvm.page_hash = &uvm_bootbucket; /* install bootstrap bucket */ TAILQ_INIT(uvm.page_hash); /* init hash table */ simple_lock_init(&uvm.hashlock); /* init hash table lock */ /* * allocate vm_page structures. */ /* * sanity check: * before calling this function the MD code is expected to register * some free RAM with the uvm_page_physload() function. our job * now is to allocate vm_page structures for this memory. */ if (vm_nphysseg == 0) panic("uvm_page_bootstrap: no memory pre-allocated"); /* * first calculate the number of free pages... * * note that we use start/end rather than avail_start/avail_end. * this allows us to allocate extra vm_page structures in case we * want to return some memory to the pool after booting. */ freepages = 0; for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) freepages += (vm_physmem[lcv].end - vm_physmem[lcv].start); /* * Let MD code initialize the number of colors, or default * to 1 color if MD code doesn't care. */ if (uvmexp.ncolors == 0) uvmexp.ncolors = 1; uvmexp.colormask = uvmexp.ncolors - 1; /* * we now know we have (PAGE_SIZE * freepages) bytes of memory we can * use. for each page of memory we use we need a vm_page structure. * thus, the total number of pages we can use is the total size of * the memory divided by the PAGE_SIZE plus the size of the vm_page * structure. we add one to freepages as a fudge factor to avoid * truncation errors (since we can only allocate in terms of whole * pages). */ bucketcount = uvmexp.ncolors * VM_NFREELIST; pagecount = ((freepages + 1) << PAGE_SHIFT) / (PAGE_SIZE + sizeof(struct vm_page)); bucketarray = (void *)uvm_pageboot_alloc((bucketcount * sizeof(struct pgflbucket)) + (pagecount * sizeof(struct vm_page))); pagearray = (struct vm_page *)(bucketarray + bucketcount); for (lcv = 0; lcv < VM_NFREELIST; lcv++) { uvm.page_free[lcv].pgfl_buckets = (bucketarray + (lcv * uvmexp.ncolors)); uvm_page_init_buckets(&uvm.page_free[lcv]); } memset(pagearray, 0, pagecount * sizeof(struct vm_page)); /* * init the vm_page structures and put them in the correct place. */ for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { n = vm_physmem[lcv].end - vm_physmem[lcv].start; /* set up page array pointers */ vm_physmem[lcv].pgs = pagearray; pagearray += n; pagecount -= n; vm_physmem[lcv].lastpg = vm_physmem[lcv].pgs + (n - 1); /* init and free vm_pages (we've already zeroed them) */ paddr = ptoa(vm_physmem[lcv].start); for (i = 0 ; i < n ; i++, paddr += PAGE_SIZE) { vm_physmem[lcv].pgs[i].phys_addr = paddr; #ifdef __HAVE_VM_PAGE_MD VM_MDPAGE_INIT(&vm_physmem[lcv].pgs[i]); #endif if (atop(paddr) >= vm_physmem[lcv].avail_start && atop(paddr) <= vm_physmem[lcv].avail_end) { uvmexp.npages++; /* add page to free pool */ uvm_pagefree(&vm_physmem[lcv].pgs[i]); } } } /* * pass up the values of virtual_space_start and * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper * layers of the VM. */ *kvm_startp = round_page(virtual_space_start); *kvm_endp = trunc_page(virtual_space_end); #ifdef DEBUG /* * steal kva for uvm_pagezerocheck(). */ uvm_zerocheckkva = *kvm_startp; *kvm_startp += PAGE_SIZE; #endif /* DEBUG */ /* * init locks for kernel threads */ simple_lock_init(&uvm.pagedaemon_lock); simple_lock_init(&uvm.aiodoned_lock); /* * init various thresholds. */ uvmexp.reserve_pagedaemon = 1; uvmexp.reserve_kernel = 5; uvmexp.anonminpct = 10; uvmexp.fileminpct = 10; uvmexp.execminpct = 5; uvmexp.anonmaxpct = 80; uvmexp.filemaxpct = 50; uvmexp.execmaxpct = 30; uvmexp.anonmin = uvmexp.anonminpct * 256 / 100; uvmexp.filemin = uvmexp.fileminpct * 256 / 100; uvmexp.execmin = uvmexp.execminpct * 256 / 100; uvmexp.anonmax = uvmexp.anonmaxpct * 256 / 100; uvmexp.filemax = uvmexp.filemaxpct * 256 / 100; uvmexp.execmax = uvmexp.execmaxpct * 256 / 100; /* * determine if we should zero pages in the idle loop. */ uvm.page_idle_zero = vm_page_zero_enable; /* * done! */ uvm.page_init_done = TRUE; } /* * uvm_setpagesize: set the page size * * => sets page_shift and page_mask from uvmexp.pagesize. */ void uvm_setpagesize() { /* * If uvmexp.pagesize is 0 at this point, we expect PAGE_SIZE * to be a constant (indicated by being a non-zero value). */ if (uvmexp.pagesize == 0) { if (PAGE_SIZE == 0) panic("uvm_setpagesize: uvmexp.pagesize not set"); uvmexp.pagesize = PAGE_SIZE; } uvmexp.pagemask = uvmexp.pagesize - 1; if ((uvmexp.pagemask & uvmexp.pagesize) != 0) panic("uvm_setpagesize: page size not a power of two"); for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) if ((1 << uvmexp.pageshift) == uvmexp.pagesize) break; } /* * uvm_pageboot_alloc: steal memory from physmem for bootstrapping */ vaddr_t uvm_pageboot_alloc(size) vsize_t size; { static boolean_t initialized = FALSE; vaddr_t addr; #if !defined(PMAP_STEAL_MEMORY) vaddr_t vaddr; paddr_t paddr; #endif /* * on first call to this function, initialize ourselves. */ if (initialized == FALSE) { pmap_virtual_space(&virtual_space_start, &virtual_space_end); /* round it the way we like it */ virtual_space_start = round_page(virtual_space_start); virtual_space_end = trunc_page(virtual_space_end); initialized = TRUE; } /* round to page size */ size = round_page(size); #if defined(PMAP_STEAL_MEMORY) /* * defer bootstrap allocation to MD code (it may want to allocate * from a direct-mapped segment). pmap_steal_memory should adjust * virtual_space_start/virtual_space_end if necessary. */ addr = pmap_steal_memory(size, &virtual_space_start, &virtual_space_end); return(addr); #else /* !PMAP_STEAL_MEMORY */ /* * allocate virtual memory for this request */ if (virtual_space_start == virtual_space_end || (virtual_space_end - virtual_space_start) < size) panic("uvm_pageboot_alloc: out of virtual space"); addr = virtual_space_start; #ifdef PMAP_GROWKERNEL /* * If the kernel pmap can't map the requested space, * then allocate more resources for it. */ if (uvm_maxkaddr < (addr + size)) { uvm_maxkaddr = pmap_growkernel(addr + size); if (uvm_maxkaddr < (addr + size)) panic("uvm_pageboot_alloc: pmap_growkernel() failed"); } #endif virtual_space_start += size; /* * allocate and mapin physical pages to back new virtual pages */ for (vaddr = round_page(addr) ; vaddr < addr + size ; vaddr += PAGE_SIZE) { if (!uvm_page_physget(&paddr)) panic("uvm_pageboot_alloc: out of memory"); /* * Note this memory is no longer managed, so using * pmap_kenter is safe. */ pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE); } pmap_update(pmap_kernel()); return(addr); #endif /* PMAP_STEAL_MEMORY */ } #if !defined(PMAP_STEAL_MEMORY) /* * uvm_page_physget: "steal" one page from the vm_physmem structure. * * => attempt to allocate it off the end of a segment in which the "avail" * values match the start/end values. if we can't do that, then we * will advance both values (making them equal, and removing some * vm_page structures from the non-avail area). * => return false if out of memory. */ /* subroutine: try to allocate from memory chunks on the specified freelist */ static boolean_t uvm_page_physget_freelist(paddr_t *, int); static boolean_t uvm_page_physget_freelist(paddrp, freelist) paddr_t *paddrp; int freelist; { int lcv, x; /* pass 1: try allocating from a matching end */ #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) #else for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) #endif { if (uvm.page_init_done == TRUE) panic("uvm_page_physget: called _after_ bootstrap"); if (vm_physmem[lcv].free_list != freelist) continue; /* try from front */ if (vm_physmem[lcv].avail_start == vm_physmem[lcv].start && vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { *paddrp = ptoa(vm_physmem[lcv].avail_start); vm_physmem[lcv].avail_start++; vm_physmem[lcv].start++; /* nothing left? nuke it */ if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) { if (vm_nphysseg == 1) panic("uvm_page_physget: out of memory!"); vm_nphysseg--; for (x = lcv ; x < vm_nphysseg ; x++) /* structure copy */ vm_physmem[x] = vm_physmem[x+1]; } return (TRUE); } /* try from rear */ if (vm_physmem[lcv].avail_end == vm_physmem[lcv].end && vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { *paddrp = ptoa(vm_physmem[lcv].avail_end - 1); vm_physmem[lcv].avail_end--; vm_physmem[lcv].end--; /* nothing left? nuke it */ if (vm_physmem[lcv].avail_end == vm_physmem[lcv].start) { if (vm_nphysseg == 1) panic("uvm_page_physget: out of memory!"); vm_nphysseg--; for (x = lcv ; x < vm_nphysseg ; x++) /* structure copy */ vm_physmem[x] = vm_physmem[x+1]; } return (TRUE); } } /* pass2: forget about matching ends, just allocate something */ #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) #else for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) #endif { /* any room in this bank? */ if (vm_physmem[lcv].avail_start >= vm_physmem[lcv].avail_end) continue; /* nope */ *paddrp = ptoa(vm_physmem[lcv].avail_start); vm_physmem[lcv].avail_start++; /* truncate! */ vm_physmem[lcv].start = vm_physmem[lcv].avail_start; /* nothing left? nuke it */ if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) { if (vm_nphysseg == 1) panic("uvm_page_physget: out of memory!"); vm_nphysseg--; for (x = lcv ; x < vm_nphysseg ; x++) /* structure copy */ vm_physmem[x] = vm_physmem[x+1]; } return (TRUE); } return (FALSE); /* whoops! */ } boolean_t uvm_page_physget(paddrp) paddr_t *paddrp; { int i; /* try in the order of freelist preference */ for (i = 0; i < VM_NFREELIST; i++) if (uvm_page_physget_freelist(paddrp, i) == TRUE) return (TRUE); return (FALSE); } #endif /* PMAP_STEAL_MEMORY */ /* * uvm_page_physload: load physical memory into VM system * * => all args are PFs * => all pages in start/end get vm_page structures * => areas marked by avail_start/avail_end get added to the free page pool * => we are limited to VM_PHYSSEG_MAX physical memory segments */ void uvm_page_physload(start, end, avail_start, avail_end, free_list) paddr_t start, end, avail_start, avail_end; int free_list; { int preload, lcv; psize_t npages; struct vm_page *pgs; struct vm_physseg *ps; if (uvmexp.pagesize == 0) panic("uvm_page_physload: page size not set!"); if (free_list >= VM_NFREELIST || free_list < VM_FREELIST_DEFAULT) panic("uvm_page_physload: bad free list %d", free_list); if (start >= end) panic("uvm_page_physload: start >= end"); /* * do we have room? */ if (vm_nphysseg == VM_PHYSSEG_MAX) { printf("uvm_page_physload: unable to load physical memory " "segment\n"); printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n", VM_PHYSSEG_MAX, (long long)start, (long long)end); printf("\tincrease VM_PHYSSEG_MAX\n"); return; } /* * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been * called yet, so malloc is not available). */ for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { if (vm_physmem[lcv].pgs) break; } preload = (lcv == vm_nphysseg); /* * if VM is already running, attempt to malloc() vm_page structures */ if (!preload) { #if defined(VM_PHYSSEG_NOADD) panic("uvm_page_physload: tried to add RAM after vm_mem_init"); #else /* XXXCDC: need some sort of lockout for this case */ paddr_t paddr; npages = end - start; /* # of pages */ pgs = malloc(sizeof(struct vm_page) * npages, M_VMPAGE, M_NOWAIT); if (pgs == NULL) { printf("uvm_page_physload: can not malloc vm_page " "structs for segment\n"); printf("\tignoring 0x%lx -> 0x%lx\n", start, end); return; } /* zero data, init phys_addr and free_list, and free pages */ memset(pgs, 0, sizeof(struct vm_page) * npages); for (lcv = 0, paddr = ptoa(start) ; lcv < npages ; lcv++, paddr += PAGE_SIZE) { pgs[lcv].phys_addr = paddr; pgs[lcv].free_list = free_list; if (atop(paddr) >= avail_start && atop(paddr) <= avail_end) uvm_pagefree(&pgs[lcv]); } /* XXXCDC: incomplete: need to update uvmexp.free, what else? */ /* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */ #endif } else { pgs = NULL; npages = 0; } /* * now insert us in the proper place in vm_physmem[] */ #if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM) /* random: put it at the end (easy!) */ ps = &vm_physmem[vm_nphysseg]; #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) { int x; /* sort by address for binary search */ for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) if (start < vm_physmem[lcv].start) break; ps = &vm_physmem[lcv]; /* move back other entries, if necessary ... */ for (x = vm_nphysseg ; x > lcv ; x--) /* structure copy */ vm_physmem[x] = vm_physmem[x - 1]; } #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) { int x; /* sort by largest segment first */ for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) if ((end - start) > (vm_physmem[lcv].end - vm_physmem[lcv].start)) break; ps = &vm_physmem[lcv]; /* move back other entries, if necessary ... */ for (x = vm_nphysseg ; x > lcv ; x--) /* structure copy */ vm_physmem[x] = vm_physmem[x - 1]; } #else panic("uvm_page_physload: unknown physseg strategy selected!"); #endif ps->start = start; ps->end = end; ps->avail_start = avail_start; ps->avail_end = avail_end; if (preload) { ps->pgs = NULL; } else { ps->pgs = pgs; ps->lastpg = pgs + npages - 1; } ps->free_list = free_list; vm_nphysseg++; if (!preload) uvm_page_rehash(); } /* * uvm_page_rehash: reallocate hash table based on number of free pages. */ void uvm_page_rehash() { int freepages, lcv, bucketcount, oldcount; struct pglist *newbuckets, *oldbuckets; struct vm_page *pg; size_t newsize, oldsize; /* * compute number of pages that can go in the free pool */ freepages = 0; for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) freepages += (vm_physmem[lcv].avail_end - vm_physmem[lcv].avail_start); /* * compute number of buckets needed for this number of pages */ bucketcount = 1; while (bucketcount < freepages) bucketcount = bucketcount * 2; /* * compute the size of the current table and new table. */ oldbuckets = uvm.page_hash; oldcount = uvm.page_nhash; oldsize = round_page(sizeof(struct pglist) * oldcount); newsize = round_page(sizeof(struct pglist) * bucketcount); /* * allocate the new buckets */ newbuckets = (struct pglist *) uvm_km_alloc(kernel_map, newsize, 0, UVM_KMF_WIRED); if (newbuckets == NULL) { printf("uvm_page_physrehash: WARNING: could not grow page " "hash table\n"); return; } for (lcv = 0 ; lcv < bucketcount ; lcv++) TAILQ_INIT(&newbuckets[lcv]); /* * now replace the old buckets with the new ones and rehash everything */ simple_lock(&uvm.hashlock); uvm.page_hash = newbuckets; uvm.page_nhash = bucketcount; uvm.page_hashmask = bucketcount - 1; /* power of 2 */ /* ... and rehash */ for (lcv = 0 ; lcv < oldcount ; lcv++) { while ((pg = oldbuckets[lcv].tqh_first) != NULL) { TAILQ_REMOVE(&oldbuckets[lcv], pg, hashq); TAILQ_INSERT_TAIL( &uvm.page_hash[uvm_pagehash(pg->uobject, pg->offset)], pg, hashq); } } simple_unlock(&uvm.hashlock); /* * free old bucket array if is not the boot-time table */ if (oldbuckets != &uvm_bootbucket) uvm_km_free(kernel_map, (vaddr_t) oldbuckets, oldsize, UVM_KMF_WIRED); } /* * uvm_page_recolor: Recolor the pages if the new bucket count is * larger than the old one. */ void uvm_page_recolor(int newncolors) { struct pgflbucket *bucketarray, *oldbucketarray; struct pgfreelist pgfl; struct vm_page *pg; vsize_t bucketcount; int s, lcv, color, i, ocolors; if (newncolors <= uvmexp.ncolors) return; if (uvm.page_init_done == FALSE) { uvmexp.ncolors = newncolors; return; } bucketcount = newncolors * VM_NFREELIST; bucketarray = malloc(bucketcount * sizeof(struct pgflbucket), M_VMPAGE, M_NOWAIT); if (bucketarray == NULL) { printf("WARNING: unable to allocate %ld page color buckets\n", (long) bucketcount); return; } s = uvm_lock_fpageq(); /* Make sure we should still do this. */ if (newncolors <= uvmexp.ncolors) { uvm_unlock_fpageq(s); free(bucketarray, M_VMPAGE); return; } oldbucketarray = uvm.page_free[0].pgfl_buckets; ocolors = uvmexp.ncolors; uvmexp.ncolors = newncolors; uvmexp.colormask = uvmexp.ncolors - 1; for (lcv = 0; lcv < VM_NFREELIST; lcv++) { pgfl.pgfl_buckets = (bucketarray + (lcv * newncolors)); uvm_page_init_buckets(&pgfl); for (color = 0; color < ocolors; color++) { for (i = 0; i < PGFL_NQUEUES; i++) { while ((pg = TAILQ_FIRST(&uvm.page_free[ lcv].pgfl_buckets[color].pgfl_queues[i])) != NULL) { TAILQ_REMOVE(&uvm.page_free[ lcv].pgfl_buckets[ color].pgfl_queues[i], pg, pageq); TAILQ_INSERT_TAIL(&pgfl.pgfl_buckets[ VM_PGCOLOR_BUCKET(pg)].pgfl_queues[ i], pg, pageq); } } } uvm.page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets; } if (have_recolored_pages) { uvm_unlock_fpageq(s); free(oldbucketarray, M_VMPAGE); return; } have_recolored_pages = TRUE; uvm_unlock_fpageq(s); } /* * uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat */ static __inline struct vm_page * uvm_pagealloc_pgfl(struct pgfreelist *pgfl, int try1, int try2, int *trycolorp) { struct pglist *freeq; struct vm_page *pg; int color, trycolor = *trycolorp; color = trycolor; do { if ((pg = TAILQ_FIRST((freeq = &pgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL) goto gotit; if ((pg = TAILQ_FIRST((freeq = &pgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL) goto gotit; color = (color + 1) & uvmexp.colormask; } while (color != trycolor); return (NULL); gotit: TAILQ_REMOVE(freeq, pg, pageq); uvmexp.free--; /* update zero'd page count */ if (pg->flags & PG_ZERO) uvmexp.zeropages--; if (color == trycolor) uvmexp.colorhit++; else { uvmexp.colormiss++; *trycolorp = color; } return (pg); } /* * uvm_pagealloc_strat: allocate vm_page from a particular free list. * * => return null if no pages free * => wake up pagedaemon if number of free pages drops below low water mark * => if obj != NULL, obj must be locked (to put in hash) * => if anon != NULL, anon must be locked (to put in anon) * => only one of obj or anon can be non-null * => caller must activate/deactivate page if it is not wired. * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL. * => policy decision: it is more important to pull a page off of the * appropriate priority free list than it is to get a zero'd or * unknown contents page. This is because we live with the * consequences of a bad free list decision for the entire * lifetime of the page, e.g. if the page comes from memory that * is slower to access. */ struct vm_page * uvm_pagealloc_strat(obj, off, anon, flags, strat, free_list) struct uvm_object *obj; voff_t off; int flags; struct vm_anon *anon; int strat, free_list; { int lcv, try1, try2, s, zeroit = 0, color; struct vm_page *pg; boolean_t use_reserve; KASSERT(obj == NULL || anon == NULL); KASSERT(off == trunc_page(off)); LOCK_ASSERT(obj == NULL || simple_lock_held(&obj->vmobjlock)); LOCK_ASSERT(anon == NULL || simple_lock_held(&anon->an_lock)); s = uvm_lock_fpageq(); /* * This implements a global round-robin page coloring * algorithm. * * XXXJRT: Should we make the `nextcolor' per-CPU? * XXXJRT: What about virtually-indexed caches? */ color = uvm.page_free_nextcolor; /* * check to see if we need to generate some free pages waking * the pagedaemon. */ UVM_KICK_PDAEMON(); /* * fail if any of these conditions is true: * [1] there really are no free pages, or * [2] only kernel "reserved" pages remain and * the page isn't being allocated to a kernel object. * [3] only pagedaemon "reserved" pages remain and * the requestor isn't the pagedaemon. */ use_reserve = (flags & UVM_PGA_USERESERVE) || (obj && UVM_OBJ_IS_KERN_OBJECT(obj)); if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) || (uvmexp.free <= uvmexp.reserve_pagedaemon && !(use_reserve && curproc == uvm.pagedaemon_proc))) goto fail; #if PGFL_NQUEUES != 2 #error uvm_pagealloc_strat needs to be updated #endif /* * If we want a zero'd page, try the ZEROS queue first, otherwise * we try the UNKNOWN queue first. */ if (flags & UVM_PGA_ZERO) { try1 = PGFL_ZEROS; try2 = PGFL_UNKNOWN; } else { try1 = PGFL_UNKNOWN; try2 = PGFL_ZEROS; } again: switch (strat) { case UVM_PGA_STRAT_NORMAL: /* Check all freelists in descending priority order. */ for (lcv = 0; lcv < VM_NFREELIST; lcv++) { pg = uvm_pagealloc_pgfl(&uvm.page_free[lcv], try1, try2, &color); if (pg != NULL) goto gotit; } /* No pages free! */ goto fail; case UVM_PGA_STRAT_ONLY: case UVM_PGA_STRAT_FALLBACK: /* Attempt to allocate from the specified free list. */ KASSERT(free_list >= 0 && free_list < VM_NFREELIST); pg = uvm_pagealloc_pgfl(&uvm.page_free[free_list], try1, try2, &color); if (pg != NULL) goto gotit; /* Fall back, if possible. */ if (strat == UVM_PGA_STRAT_FALLBACK) { strat = UVM_PGA_STRAT_NORMAL; goto again; } /* No pages free! */ goto fail; default: panic("uvm_pagealloc_strat: bad strat %d", strat); /* NOTREACHED */ } gotit: /* * We now know which color we actually allocated from; set * the next color accordingly. */ uvm.page_free_nextcolor = (color + 1) & uvmexp.colormask; /* * update allocation statistics and remember if we have to * zero the page */ if (flags & UVM_PGA_ZERO) { if (pg->flags & PG_ZERO) { uvmexp.pga_zerohit++; zeroit = 0; } else { uvmexp.pga_zeromiss++; zeroit = 1; } } uvm_unlock_fpageq(s); pg->offset = off; pg->uobject = obj; pg->uanon = anon; pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE; if (anon) { anon->an_page = pg; pg->pqflags = PQ_ANON; uvmexp.anonpages++; } else { if (obj) { uvm_pageinsert(pg); } pg->pqflags = 0; } #if defined(UVM_PAGE_TRKOWN) pg->owner_tag = NULL; #endif UVM_PAGE_OWN(pg, "new alloc"); if (flags & UVM_PGA_ZERO) { /* * A zero'd page is not clean. If we got a page not already * zero'd, then we have to zero it ourselves. */ pg->flags &= ~PG_CLEAN; if (zeroit) pmap_zero_page(VM_PAGE_TO_PHYS(pg)); } return(pg); fail: uvm_unlock_fpageq(s); return (NULL); } /* * uvm_pagereplace: replace a page with another * * => object must be locked */ void uvm_pagereplace(oldpg, newpg) struct vm_page *oldpg; struct vm_page *newpg; { KASSERT((oldpg->flags & PG_TABLED) != 0); KASSERT(oldpg->uobject != NULL); KASSERT((newpg->flags & PG_TABLED) == 0); KASSERT(newpg->uobject == NULL); LOCK_ASSERT(simple_lock_held(&oldpg->uobject->vmobjlock)); newpg->uobject = oldpg->uobject; newpg->offset = oldpg->offset; uvm_pageinsert_after(newpg, oldpg); uvm_pageremove(oldpg); } /* * uvm_pagerealloc: reallocate a page from one object to another * * => both objects must be locked */ void uvm_pagerealloc(pg, newobj, newoff) struct vm_page *pg; struct uvm_object *newobj; voff_t newoff; { /* * remove it from the old object */ if (pg->uobject) { uvm_pageremove(pg); } /* * put it in the new object */ if (newobj) { pg->uobject = newobj; pg->offset = newoff; uvm_pageinsert(pg); } } #ifdef DEBUG /* * check if page is zero-filled * * - called with free page queue lock held. */ void uvm_pagezerocheck(struct vm_page *pg) { int *p, *ep; KASSERT(uvm_zerocheckkva != 0); LOCK_ASSERT(simple_lock_held(&uvm.fpageqlock)); /* * XXX assuming pmap_kenter_pa and pmap_kremove never call * uvm page allocator. * * it might be better to have "CPU-local temporary map" pmap interface. */ pmap_kenter_pa(uvm_zerocheckkva, VM_PAGE_TO_PHYS(pg), VM_PROT_READ); p = (int *)uvm_zerocheckkva; ep = (int *)((char *)p + PAGE_SIZE); pmap_update(pmap_kernel()); while (p < ep) { if (*p != 0) panic("PG_ZERO page isn't zero-filled"); p++; } pmap_kremove(uvm_zerocheckkva, PAGE_SIZE); } #endif /* DEBUG */ /* * uvm_pagefree: free page * * => erase page's identity (i.e. remove from hash/object) * => put page on free list * => caller must lock owning object (either anon or uvm_object) * => caller must lock page queues * => assumes all valid mappings of pg are gone */ void uvm_pagefree(pg) struct vm_page *pg; { int s; struct pglist *pgfl; boolean_t iszero; KASSERT((pg->flags & PG_PAGEOUT) == 0); LOCK_ASSERT(simple_lock_held(&uvm.pageqlock) || (pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) == 0); LOCK_ASSERT(pg->uobject == NULL || simple_lock_held(&pg->uobject->vmobjlock)); LOCK_ASSERT(pg->uobject != NULL || pg->uanon == NULL || simple_lock_held(&pg->uanon->an_lock)); #ifdef DEBUG if (pg->uobject == (void *)0xdeadbeef && pg->uanon == (void *)0xdeadbeef) { panic("uvm_pagefree: freeing free page %p", pg); } #endif /* DEBUG */ /* * if the page is loaned, resolve the loan instead of freeing. */ if (pg->loan_count) { KASSERT(pg->wire_count == 0); /* * if the page is owned by an anon then we just want to * drop anon ownership. the kernel will free the page when * it is done with it. if the page is owned by an object, * remove it from the object and mark it dirty for the benefit * of possible anon owners. * * regardless of previous ownership, wakeup any waiters, * unbusy the page, and we're done. */ if (pg->uobject != NULL) { uvm_pageremove(pg); pg->flags &= ~PG_CLEAN; } else if (pg->uanon != NULL) { if ((pg->pqflags & PQ_ANON) == 0) { pg->loan_count--; } else { pg->pqflags &= ~PQ_ANON; uvmexp.anonpages--; } pg->uanon->an_page = NULL; pg->uanon = NULL; } if (pg->flags & PG_WANTED) { wakeup(pg); } pg->flags &= ~(PG_WANTED|PG_BUSY|PG_RELEASED|PG_PAGER1); #ifdef UVM_PAGE_TRKOWN pg->owner_tag = NULL; #endif if (pg->loan_count) { uvm_pagedequeue(pg); return; } } /* * remove page from its object or anon. */ if (pg->uobject != NULL) { uvm_pageremove(pg); } else if (pg->uanon != NULL) { pg->uanon->an_page = NULL; uvmexp.anonpages--; } /* * now remove the page from the queues. */ uvm_pagedequeue(pg); /* * if the page was wired, unwire it now. */ if (pg->wire_count) { pg->wire_count = 0; uvmexp.wired--; } /* * and put on free queue */ iszero = (pg->flags & PG_ZERO); pgfl = &uvm.page_free[uvm_page_lookup_freelist(pg)]. pgfl_buckets[VM_PGCOLOR_BUCKET(pg)]. pgfl_queues[iszero ? PGFL_ZEROS : PGFL_UNKNOWN]; pg->pqflags = PQ_FREE; #ifdef DEBUG pg->uobject = (void *)0xdeadbeef; pg->offset = 0xdeadbeef; pg->uanon = (void *)0xdeadbeef; #endif s = uvm_lock_fpageq(); #ifdef DEBUG if (iszero) uvm_pagezerocheck(pg); #endif /* DEBUG */ TAILQ_INSERT_HEAD(pgfl, pg, pageq); uvmexp.free++; if (iszero) uvmexp.zeropages++; if (uvmexp.zeropages < UVM_PAGEZERO_TARGET) uvm.page_idle_zero = vm_page_zero_enable; uvm_unlock_fpageq(s); } /* * uvm_page_unbusy: unbusy an array of pages. * * => pages must either all belong to the same object, or all belong to anons. * => if pages are object-owned, object must be locked. * => if pages are anon-owned, anons must be locked. * => caller must lock page queues if pages may be released. * => caller must make sure that anon-owned pages are not PG_RELEASED. */ void uvm_page_unbusy(pgs, npgs) struct vm_page **pgs; int npgs; { struct vm_page *pg; int i; UVMHIST_FUNC("uvm_page_unbusy"); UVMHIST_CALLED(ubchist); for (i = 0; i < npgs; i++) { pg = pgs[i]; if (pg == NULL || pg == PGO_DONTCARE) { continue; } LOCK_ASSERT(pg->uobject == NULL || simple_lock_held(&pg->uobject->vmobjlock)); LOCK_ASSERT(pg->uobject != NULL || (pg->uanon != NULL && simple_lock_held(&pg->uanon->an_lock))); KASSERT(pg->flags & PG_BUSY); KASSERT((pg->flags & PG_PAGEOUT) == 0); if (pg->flags & PG_WANTED) { wakeup(pg); } if (pg->flags & PG_RELEASED) { UVMHIST_LOG(ubchist, "releasing pg %p", pg,0,0,0); KASSERT(pg->uobject != NULL || (pg->uanon != NULL && pg->uanon->an_ref > 0)); pg->flags &= ~PG_RELEASED; uvm_pagefree(pg); } else { UVMHIST_LOG(ubchist, "unbusying pg %p", pg,0,0,0); pg->flags &= ~(PG_WANTED|PG_BUSY); UVM_PAGE_OWN(pg, NULL); } } } #if defined(UVM_PAGE_TRKOWN) /* * uvm_page_own: set or release page ownership * * => this is a debugging function that keeps track of who sets PG_BUSY * and where they do it. it can be used to track down problems * such a process setting "PG_BUSY" and never releasing it. * => page's object [if any] must be locked * => if "tag" is NULL then we are releasing page ownership */ void uvm_page_own(pg, tag) struct vm_page *pg; char *tag; { KASSERT((pg->flags & (PG_PAGEOUT|PG_RELEASED)) == 0); /* gain ownership? */ if (tag) { if (pg->owner_tag) { printf("uvm_page_own: page %p already owned " "by proc %d [%s]\n", pg, pg->owner, pg->owner_tag); panic("uvm_page_own"); } pg->owner = (curproc) ? curproc->p_pid : (pid_t) -1; pg->owner_tag = tag; return; } /* drop ownership */ if (pg->owner_tag == NULL) { printf("uvm_page_own: dropping ownership of an non-owned " "page (%p)\n", pg); panic("uvm_page_own"); } KASSERT((pg->pqflags & (PQ_ACTIVE|PQ_INACTIVE)) || (pg->uanon == NULL && pg->uobject == NULL) || pg->uobject == uvm.kernel_object || pg->wire_count > 0 || (pg->loan_count == 1 && pg->uanon == NULL) || pg->loan_count > 1); pg->owner_tag = NULL; } #endif /* * uvm_pageidlezero: zero free pages while the system is idle. * * => try to complete one color bucket at a time, to reduce our impact * on the CPU cache. * => we loop until we either reach the target or whichqs indicates that * there is a process ready to run. */ void uvm_pageidlezero() { struct vm_page *pg; struct pgfreelist *pgfl; int free_list, s, firstbucket; static int nextbucket; KERNEL_LOCK(LK_EXCLUSIVE | LK_CANRECURSE); s = uvm_lock_fpageq(); firstbucket = nextbucket; do { if (sched_whichqs != 0) goto quit; if (uvmexp.zeropages >= UVM_PAGEZERO_TARGET) { uvm.page_idle_zero = FALSE; goto quit; } for (free_list = 0; free_list < VM_NFREELIST; free_list++) { pgfl = &uvm.page_free[free_list]; while ((pg = TAILQ_FIRST(&pgfl->pgfl_buckets[ nextbucket].pgfl_queues[PGFL_UNKNOWN])) != NULL) { if (sched_whichqs != 0) goto quit; TAILQ_REMOVE(&pgfl->pgfl_buckets[ nextbucket].pgfl_queues[PGFL_UNKNOWN], pg, pageq); uvmexp.free--; uvm_unlock_fpageq(s); KERNEL_UNLOCK(); #ifdef PMAP_PAGEIDLEZERO if (!PMAP_PAGEIDLEZERO(VM_PAGE_TO_PHYS(pg))) { /* * The machine-dependent code detected * some reason for us to abort zeroing * pages, probably because there is a * process now ready to run. */ KERNEL_LOCK( LK_EXCLUSIVE | LK_CANRECURSE); s = uvm_lock_fpageq(); TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ nextbucket].pgfl_queues[ PGFL_UNKNOWN], pg, pageq); uvmexp.free++; uvmexp.zeroaborts++; goto quit; } #else pmap_zero_page(VM_PAGE_TO_PHYS(pg)); #endif /* PMAP_PAGEIDLEZERO */ pg->flags |= PG_ZERO; KERNEL_LOCK(LK_EXCLUSIVE | LK_CANRECURSE); s = uvm_lock_fpageq(); TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[ nextbucket].pgfl_queues[PGFL_ZEROS], pg, pageq); uvmexp.free++; uvmexp.zeropages++; } } nextbucket = (nextbucket + 1) & uvmexp.colormask; } while (nextbucket != firstbucket); quit: uvm_unlock_fpageq(s); KERNEL_UNLOCK(); }