/* * Copyright (c) 1994 John S. Dyson * Copyright (c) 1990 University of Utah. * 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 Systems Programming Group of the University of Utah Computer * Science Department. * * 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 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. * * from: Utah $Hdr: swap_pager.c 1.4 91/04/30$ * * @(#)swap_pager.c 8.9 (Berkeley) 3/21/94 * $Id: swap_pager.c,v 1.48 1995/11/02 06:42:45 davidg Exp $ */ /* * Quick hack to page to dedicated partition(s). * TODO: * Add multiprocessor locks * Deal with async writes in a better fashion */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef NPENDINGIO #define NPENDINGIO 10 #endif int nswiodone; int swap_pager_full; extern int vm_swap_size; static int no_swap_space = 1; struct rlist *swaplist; int nswaplist; #define MAX_PAGEOUT_CLUSTER 8 TAILQ_HEAD(swpclean, swpagerclean); typedef struct swpagerclean *swp_clean_t; struct swpagerclean { TAILQ_ENTRY(swpagerclean) spc_list; int spc_flags; struct buf *spc_bp; vm_object_t spc_object; vm_offset_t spc_kva; int spc_count; vm_page_t spc_m[MAX_PAGEOUT_CLUSTER]; } swcleanlist[NPENDINGIO]; /* spc_flags values */ #define SPC_ERROR 0x01 #define SWB_EMPTY (-1) struct swpclean swap_pager_done; /* list of completed page cleans */ struct swpclean swap_pager_inuse; /* list of pending page cleans */ struct swpclean swap_pager_free; /* list of free pager clean structs */ struct pagerlst swap_pager_object_list; /* list of "named" anon region objects */ struct pagerlst swap_pager_un_object_list; /* list of "unnamed" anon region objects */ #define SWAP_FREE_NEEDED 0x1 /* need a swap block */ #define SWAP_FREE_NEEDED_BY_PAGEOUT 0x2 int swap_pager_needflags; static struct pagerlst *swp_qs[] = { &swap_pager_object_list, &swap_pager_un_object_list, (struct pagerlst *) 0 }; /* * pagerops for OBJT_SWAP - "swap pager". */ struct pagerops swappagerops = { swap_pager_init, swap_pager_alloc, swap_pager_dealloc, swap_pager_getpages, swap_pager_putpages, swap_pager_haspage, swap_pager_sync }; static int npendingio = NPENDINGIO; static void swap_pager_finish(); int dmmin, dmmax; static inline void swapsizecheck() { if (vm_swap_size < 128 * btodb(PAGE_SIZE)) { if (swap_pager_full == 0) printf("swap_pager: out of space\n"); swap_pager_full = 1; } else if (vm_swap_size > 192 * btodb(PAGE_SIZE)) swap_pager_full = 0; } static void swap_pager_init() { TAILQ_INIT(&swap_pager_object_list); TAILQ_INIT(&swap_pager_un_object_list); /* * Initialize clean lists */ TAILQ_INIT(&swap_pager_inuse); TAILQ_INIT(&swap_pager_done); TAILQ_INIT(&swap_pager_free); /* * Calculate the swap allocation constants. */ dmmin = CLBYTES / DEV_BSIZE; dmmax = btodb(SWB_NPAGES * PAGE_SIZE) * 2; } void swap_pager_swap_init() { swp_clean_t spc; struct buf *bp; int i; /* * kva's are allocated here so that we dont need to keep doing * kmem_alloc pageables at runtime */ for (i = 0, spc = swcleanlist; i < npendingio; i++, spc++) { spc->spc_kva = kmem_alloc_pageable(pager_map, PAGE_SIZE * MAX_PAGEOUT_CLUSTER); if (!spc->spc_kva) { break; } spc->spc_bp = malloc(sizeof(*bp), M_TEMP, M_KERNEL); if (!spc->spc_bp) { kmem_free_wakeup(pager_map, spc->spc_kva, PAGE_SIZE); break; } spc->spc_flags = 0; TAILQ_INSERT_TAIL(&swap_pager_free, spc, spc_list); } } int swap_pager_swp_alloc(object, wait) vm_object_t object; int wait; { sw_blk_t swb; int nblocks; int i, j; nblocks = (btodb(object->size) + btodb(SWB_NPAGES * PAGE_SIZE) - 1) / btodb(SWB_NPAGES * PAGE_SIZE); swb = malloc(nblocks * sizeof(*swb), M_VMPGDATA, wait); if (swb == NULL) return 1; for (i = 0; i < nblocks; i++) { swb[i].swb_valid = 0; swb[i].swb_locked = 0; for (j = 0; j < SWB_NPAGES; j++) swb[i].swb_block[j] = SWB_EMPTY; } object->un_pager.swp.swp_nblocks = nblocks; object->un_pager.swp.swp_allocsize = 0; object->un_pager.swp.swp_blocks = swb; object->un_pager.swp.swp_poip = 0; if (object->handle != NULL) { TAILQ_INSERT_TAIL(&swap_pager_object_list, object, pager_object_list); } else { TAILQ_INSERT_TAIL(&swap_pager_un_object_list, object, pager_object_list); } return 0; } /* * Allocate an object and associated resources. * Note that if we are called from the pageout daemon (handle == NULL) * we should not wait for memory as it could resulting in deadlock. */ static vm_object_t swap_pager_alloc(handle, size, prot, offset) void *handle; register vm_size_t size; vm_prot_t prot; vm_offset_t offset; { vm_object_t object; int i; /* * If this is a "named" anonymous region, look it up and use the * object if it exists, otherwise allocate a new one. */ if (handle) { object = vm_pager_object_lookup(&swap_pager_object_list, handle); if (object != NULL) { vm_object_reference(object); } else { /* * XXX - there is a race condition here. Two processes * can request the same named object simultaneuously, * and if one blocks for memory, the result is a disaster. * Probably quite rare, but is yet another reason to just * rip support of "named anonymous regions" out altogether. */ object = vm_object_allocate(OBJT_SWAP, offset + size); object->handle = handle; (void) swap_pager_swp_alloc(object, M_WAITOK); } } else { object = vm_object_allocate(OBJT_SWAP, offset + size); (void) swap_pager_swp_alloc(object, M_WAITOK); } return (object); } /* * returns disk block associated with pager and offset * additionally, as a side effect returns a flag indicating * if the block has been written */ inline static int * swap_pager_diskaddr(object, offset, valid) vm_object_t object; vm_offset_t offset; int *valid; { register sw_blk_t swb; int ix; if (valid) *valid = 0; ix = offset / (SWB_NPAGES * PAGE_SIZE); if ((ix >= object->un_pager.swp.swp_nblocks) || (offset >= object->size)) { return (FALSE); } swb = &object->un_pager.swp.swp_blocks[ix]; ix = (offset % (SWB_NPAGES * PAGE_SIZE)) / PAGE_SIZE; if (valid) *valid = swb->swb_valid & (1 << ix); return &swb->swb_block[ix]; } /* * Utility routine to set the valid (written) bit for * a block associated with a pager and offset */ static void swap_pager_setvalid(object, offset, valid) vm_object_t object; vm_offset_t offset; int valid; { register sw_blk_t swb; int ix; ix = offset / (SWB_NPAGES * PAGE_SIZE); if (ix >= object->un_pager.swp.swp_nblocks) return; swb = &object->un_pager.swp.swp_blocks[ix]; ix = (offset % (SWB_NPAGES * PAGE_SIZE)) / PAGE_SIZE; if (valid) swb->swb_valid |= (1 << ix); else swb->swb_valid &= ~(1 << ix); return; } /* * this routine allocates swap space with a fragmentation * minimization policy. */ static int swap_pager_getswapspace(object, amount, rtval) vm_object_t object; unsigned int amount; unsigned int *rtval; { vm_swap_size -= amount; if (!rlist_alloc(&swaplist, amount, rtval)) { vm_swap_size += amount; return 0; } else { swapsizecheck(); object->un_pager.swp.swp_allocsize += amount; return 1; } } /* * this routine frees swap space with a fragmentation * minimization policy. */ static void swap_pager_freeswapspace(object, from, to) vm_object_t object; unsigned int from; unsigned int to; { rlist_free(&swaplist, from, to); vm_swap_size += (to - from) + 1; object->un_pager.swp.swp_allocsize -= (to - from) + 1; swapsizecheck(); } /* * this routine frees swap blocks from a specified pager */ void swap_pager_freespace(object, start, size) vm_object_t object; vm_offset_t start; vm_offset_t size; { vm_offset_t i; int s; s = splbio(); for (i = start; i < round_page(start + size); i += PAGE_SIZE) { int valid; int *addr = swap_pager_diskaddr(object, i, &valid); if (addr && *addr != SWB_EMPTY) { swap_pager_freeswapspace(object, *addr, *addr + btodb(PAGE_SIZE) - 1); if (valid) { swap_pager_setvalid(object, i, 0); } *addr = SWB_EMPTY; } } splx(s); } static void swap_pager_free_swap(object) vm_object_t object; { register int i, j; register sw_blk_t swb; int first_block=0, block_count=0; int s; /* * Free left over swap blocks */ s = splbio(); for (i = 0, swb = object->un_pager.swp.swp_blocks; i < object->un_pager.swp.swp_nblocks; i++, swb++) { for (j = 0; j < SWB_NPAGES; j++) { if (swb->swb_block[j] != SWB_EMPTY) { /* * initially the length of the run is zero */ if (block_count == 0) { first_block = swb->swb_block[j]; block_count = btodb(PAGE_SIZE); swb->swb_block[j] = SWB_EMPTY; /* * if the new block can be included into the current run */ } else if (swb->swb_block[j] == first_block + block_count) { block_count += btodb(PAGE_SIZE); swb->swb_block[j] = SWB_EMPTY; /* * terminate the previous run, and start a new one */ } else { swap_pager_freeswapspace(object, first_block, (unsigned) first_block + block_count - 1); first_block = swb->swb_block[j]; block_count = btodb(PAGE_SIZE); swb->swb_block[j] = SWB_EMPTY; } } } } if (block_count) { swap_pager_freeswapspace(object, first_block, (unsigned) first_block + block_count - 1); } splx(s); } /* * swap_pager_reclaim frees up over-allocated space from all pagers * this eliminates internal fragmentation due to allocation of space * for segments that are never swapped to. It has been written so that * it does not block until the rlist_free operation occurs; it keeps * the queues consistant. */ /* * Maximum number of blocks (pages) to reclaim per pass */ #define MAXRECLAIM 128 static void swap_pager_reclaim() { vm_object_t object; int i, j, k; int s; int reclaimcount; static struct { int address; vm_object_t object; } reclaims[MAXRECLAIM]; static int in_reclaim; /* * allow only one process to be in the swap_pager_reclaim subroutine */ s = splbio(); if (in_reclaim) { tsleep(&in_reclaim, PSWP, "swrclm", 0); splx(s); return; } in_reclaim = 1; reclaimcount = 0; /* for each pager queue */ for (k = 0; swp_qs[k]; k++) { object = swp_qs[k]->tqh_first; while (object && (reclaimcount < MAXRECLAIM)) { /* * see if any blocks associated with a pager has been * allocated but not used (written) */ for (i = 0; i < object->un_pager.swp.swp_nblocks; i++) { sw_blk_t swb = &object->un_pager.swp.swp_blocks[i]; if (swb->swb_locked) continue; for (j = 0; j < SWB_NPAGES; j++) { if (swb->swb_block[j] != SWB_EMPTY && (swb->swb_valid & (1 << j)) == 0) { reclaims[reclaimcount].address = swb->swb_block[j]; reclaims[reclaimcount++].object = object; swb->swb_block[j] = SWB_EMPTY; if (reclaimcount >= MAXRECLAIM) goto rfinished; } } } object = object->pager_object_list.tqe_next; } } rfinished: /* * free the blocks that have been added to the reclaim list */ for (i = 0; i < reclaimcount; i++) { swap_pager_freeswapspace(reclaims[i].object, reclaims[i].address, reclaims[i].address + btodb(PAGE_SIZE) - 1); } splx(s); in_reclaim = 0; wakeup(&in_reclaim); } /* * swap_pager_copy copies blocks from one pager to another and * destroys the source pager */ void swap_pager_copy(srcobject, srcoffset, dstobject, dstoffset, offset) vm_object_t srcobject; vm_offset_t srcoffset; vm_object_t dstobject; vm_offset_t dstoffset; vm_offset_t offset; { vm_offset_t i; int origsize; int s; if (vm_swap_size) no_swap_space = 0; origsize = srcobject->un_pager.swp.swp_allocsize; /* * remove the source object from the swap_pager internal queue */ if (srcobject->handle == NULL) { TAILQ_REMOVE(&swap_pager_un_object_list, srcobject, pager_object_list); } else { TAILQ_REMOVE(&swap_pager_object_list, srcobject, pager_object_list); } s = splbio(); while (srcobject->un_pager.swp.swp_poip) { tsleep(srcobject, PVM, "spgout", 0); } splx(s); /* * clean all of the pages that are currently active and finished */ swap_pager_sync(); s = splbio(); /* * transfer source to destination */ for (i = 0; i < dstobject->size; i += PAGE_SIZE) { int srcvalid, dstvalid; int *srcaddrp = swap_pager_diskaddr(srcobject, i + offset + srcoffset, &srcvalid); int *dstaddrp; /* * see if the source has space allocated */ if (srcaddrp && *srcaddrp != SWB_EMPTY) { /* * if the source is valid and the dest has no space, * then copy the allocation from the srouce to the * dest. */ if (srcvalid) { dstaddrp = swap_pager_diskaddr(dstobject, i + dstoffset, &dstvalid); /* * if the dest already has a valid block, * deallocate the source block without * copying. */ if (!dstvalid && dstaddrp && *dstaddrp != SWB_EMPTY) { swap_pager_freeswapspace(dstobject, *dstaddrp, *dstaddrp + btodb(PAGE_SIZE) - 1); *dstaddrp = SWB_EMPTY; } if (dstaddrp && *dstaddrp == SWB_EMPTY) { *dstaddrp = *srcaddrp; *srcaddrp = SWB_EMPTY; dstobject->un_pager.swp.swp_allocsize += btodb(PAGE_SIZE); srcobject->un_pager.swp.swp_allocsize -= btodb(PAGE_SIZE); swap_pager_setvalid(dstobject, i + dstoffset, 1); } } /* * if the source is not empty at this point, then * deallocate the space. */ if (*srcaddrp != SWB_EMPTY) { swap_pager_freeswapspace(srcobject, *srcaddrp, *srcaddrp + btodb(PAGE_SIZE) - 1); *srcaddrp = SWB_EMPTY; } } } splx(s); /* * Free left over swap blocks */ swap_pager_free_swap(srcobject); if (srcobject->un_pager.swp.swp_allocsize) { printf("swap_pager_copy: *warning* pager with %d blocks (orig: %d)\n", srcobject->un_pager.swp.swp_allocsize, origsize); } free(srcobject->un_pager.swp.swp_blocks, M_VMPGDATA); srcobject->un_pager.swp.swp_blocks = NULL; return; } static void swap_pager_dealloc(object) vm_object_t object; { int s; /* * Remove from list right away so lookups will fail if we block for * pageout completion. */ if (object->handle == NULL) { TAILQ_REMOVE(&swap_pager_un_object_list, object, pager_object_list); } else { TAILQ_REMOVE(&swap_pager_object_list, object, pager_object_list); } /* * Wait for all pageouts to finish and remove all entries from * cleaning list. */ s = splbio(); while (object->un_pager.swp.swp_poip) { tsleep(object, PVM, "swpout", 0); } splx(s); swap_pager_sync(); /* * Free left over swap blocks */ swap_pager_free_swap(object); if (object->un_pager.swp.swp_allocsize) { printf("swap_pager_dealloc: *warning* freeing pager with %d blocks\n", object->un_pager.swp.swp_allocsize); } /* * Free swap management resources */ free(object->un_pager.swp.swp_blocks, M_VMPGDATA); object->un_pager.swp.swp_blocks = NULL; } static inline int const swap_pager_block_index(offset) vm_offset_t offset; { return (offset / (SWB_NPAGES * PAGE_SIZE)); } static inline int const swap_pager_block_offset(offset) vm_offset_t offset; { return ((offset % (PAGE_SIZE * SWB_NPAGES)) / PAGE_SIZE); } /* * swap_pager_haspage returns TRUE if the pager has data that has * been written out. */ static boolean_t swap_pager_haspage(object, offset, before, after) vm_object_t object; vm_offset_t offset; int *before; int *after; { register sw_blk_t swb; int ix; int gix; if (before != NULL) *before = 0; if (after != NULL) *after = 0; ix = offset / (SWB_NPAGES * PAGE_SIZE); if (ix >= object->un_pager.swp.swp_nblocks) { return (FALSE); } swb = &object->un_pager.swp.swp_blocks[ix]; gix = offset / PAGE_SIZE; ix = gix % SWB_NPAGES; if (swb->swb_block[ix] != SWB_EMPTY) { if (swb->swb_valid & (1 << ix)) { int tix; if (before) { for(tix = ix - 1; tix >= 0; --tix) { if ((swb->swb_valid & (1 << tix)) == 0) break; if ((swb->swb_block[tix] + (ix - tix) * (PAGE_SIZE/DEV_BSIZE)) != swb->swb_block[ix]) break; (*before)++; } } if (after) { for(tix = ix + 1; tix < SWB_NPAGES; tix++) { if ((swb->swb_valid & (1 << tix)) == 0) break; if ((swb->swb_block[tix] - (tix - ix) * (PAGE_SIZE/DEV_BSIZE)) != swb->swb_block[ix]) break; (*after)++; } } return TRUE; } } return (FALSE); } /* * swap_pager_freepage is a convienience routine that clears the busy * bit and deallocates a page. */ static void swap_pager_freepage(m) vm_page_t m; { PAGE_WAKEUP(m); vm_page_free(m); } /* * swap_pager_ridpages is a convienience routine that deallocates all * but the required page. this is usually used in error returns that * need to invalidate the "extra" readahead pages. */ static void swap_pager_ridpages(m, count, reqpage) vm_page_t *m; int count; int reqpage; { int i; for (i = 0; i < count; i++) if (i != reqpage) swap_pager_freepage(m[i]); } /* * swap_pager_iodone1 is the completion routine for both reads and async writes */ static void swap_pager_iodone1(bp) struct buf *bp; { bp->b_flags |= B_DONE; bp->b_flags &= ~B_ASYNC; wakeup(bp); } int swap_pager_getpages(object, m, count, reqpage) vm_object_t object; vm_page_t *m; int count, reqpage; { register struct buf *bp; sw_blk_t swb[count]; register int s; int i; boolean_t rv; vm_offset_t kva, off[count]; swp_clean_t spc; vm_offset_t paging_offset; int reqaddr[count]; int sequential; int first, last; int failed; int reqdskregion; object = m[reqpage]->object; paging_offset = object->paging_offset; sequential = (m[reqpage]->offset == (object->last_read + PAGE_SIZE)); for (i = 0; i < count; i++) { vm_offset_t foff = m[i]->offset + paging_offset; int ix = swap_pager_block_index(foff); if (ix >= object->un_pager.swp.swp_nblocks) { int j; if (i <= reqpage) { swap_pager_ridpages(m, count, reqpage); return (VM_PAGER_FAIL); } for (j = i; j < count; j++) { swap_pager_freepage(m[j]); } count = i; break; } swb[i] = &object->un_pager.swp.swp_blocks[ix]; off[i] = swap_pager_block_offset(foff); reqaddr[i] = swb[i]->swb_block[off[i]]; } /* make sure that our required input request is existant */ if (reqaddr[reqpage] == SWB_EMPTY || (swb[reqpage]->swb_valid & (1 << off[reqpage])) == 0) { swap_pager_ridpages(m, count, reqpage); return (VM_PAGER_FAIL); } reqdskregion = reqaddr[reqpage] / dmmax; /* * search backwards for the first contiguous page to transfer */ failed = 0; first = 0; for (i = reqpage - 1; i >= 0; --i) { if (sequential || failed || (reqaddr[i] == SWB_EMPTY) || (swb[i]->swb_valid & (1 << off[i])) == 0 || (reqaddr[i] != (reqaddr[reqpage] + (i - reqpage) * btodb(PAGE_SIZE))) || ((reqaddr[i] / dmmax) != reqdskregion)) { failed = 1; swap_pager_freepage(m[i]); if (first == 0) first = i + 1; } } /* * search forwards for the last contiguous page to transfer */ failed = 0; last = count; for (i = reqpage + 1; i < count; i++) { if (failed || (reqaddr[i] == SWB_EMPTY) || (swb[i]->swb_valid & (1 << off[i])) == 0 || (reqaddr[i] != (reqaddr[reqpage] + (i - reqpage) * btodb(PAGE_SIZE))) || ((reqaddr[i] / dmmax) != reqdskregion)) { failed = 1; swap_pager_freepage(m[i]); if (last == count) last = i; } } count = last; if (first != 0) { for (i = first; i < count; i++) { m[i - first] = m[i]; reqaddr[i - first] = reqaddr[i]; off[i - first] = off[i]; } count -= first; reqpage -= first; } ++swb[reqpage]->swb_locked; /* * at this point: "m" is a pointer to the array of vm_page_t for * paging I/O "count" is the number of vm_page_t entries represented * by "m" "object" is the vm_object_t for I/O "reqpage" is the index * into "m" for the page actually faulted */ spc = NULL; /* we might not use an spc data structure */ if ((count == 1) && (swap_pager_free.tqh_first != NULL)) { /* * if a kva has not been allocated, we can only do a one page * transfer, so we free the other pages that might have been * allocated by vm_fault. */ swap_pager_ridpages(m, count, reqpage); m[0] = m[reqpage]; reqaddr[0] = reqaddr[reqpage]; count = 1; reqpage = 0; /* * get a swap pager clean data structure, block until we get * it */ if (swap_pager_free.tqh_first == NULL) { s = splbio(); if (curproc == pageproc) swap_pager_sync(); else pagedaemon_wakeup(); while (swap_pager_free.tqh_first == NULL) { swap_pager_needflags |= SWAP_FREE_NEEDED; if (curproc == pageproc) swap_pager_needflags |= SWAP_FREE_NEEDED_BY_PAGEOUT; tsleep(&swap_pager_free, PVM, "swpfre", 0); if (curproc == pageproc) swap_pager_sync(); else pagedaemon_wakeup(); } splx(s); } spc = swap_pager_free.tqh_first; TAILQ_REMOVE(&swap_pager_free, spc, spc_list); kva = spc->spc_kva; bp = spc->spc_bp; bzero(bp, sizeof *bp); bp->b_spc = spc; bp->b_vnbufs.le_next = NOLIST; } else { /* * Get a swap buffer header to perform the IO */ bp = getpbuf(); kva = (vm_offset_t) bp->b_data; } /* * map our page(s) into kva for input */ pmap_qenter(kva, m, count); bp->b_flags = B_BUSY | B_READ | B_CALL | B_PAGING; bp->b_iodone = swap_pager_iodone1; bp->b_proc = &proc0; /* XXX (but without B_PHYS set this is ok) */ bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred; crhold(bp->b_rcred); crhold(bp->b_wcred); bp->b_un.b_addr = (caddr_t) kva; bp->b_blkno = reqaddr[0]; bp->b_bcount = PAGE_SIZE * count; bp->b_bufsize = PAGE_SIZE * count; pbgetvp(swapdev_vp, bp); cnt.v_swapin++; cnt.v_swappgsin += count; /* * perform the I/O */ VOP_STRATEGY(bp); /* * wait for the sync I/O to complete */ s = splbio(); while ((bp->b_flags & B_DONE) == 0) { tsleep(bp, PVM, "swread", 0); } if (bp->b_flags & B_ERROR) { printf("swap_pager: I/O error - pagein failed; blkno %d, size %d, error %d\n", bp->b_blkno, bp->b_bcount, bp->b_error); rv = VM_PAGER_ERROR; } else { rv = VM_PAGER_OK; } /* * relpbuf does this, but we maintain our own buffer list also... */ if (bp->b_vp) pbrelvp(bp); splx(s); swb[reqpage]->swb_locked--; /* * remove the mapping for kernel virtual */ pmap_qremove(kva, count); if (spc) { m[reqpage]->object->last_read = m[reqpage]->offset; if (bp->b_flags & B_WANTED) wakeup(bp); /* * if we have used an spc, we need to free it. */ if (bp->b_rcred != NOCRED) crfree(bp->b_rcred); if (bp->b_wcred != NOCRED) crfree(bp->b_wcred); TAILQ_INSERT_TAIL(&swap_pager_free, spc, spc_list); if (swap_pager_needflags & SWAP_FREE_NEEDED) { wakeup(&swap_pager_free); } if (swap_pager_needflags & SWAP_FREE_NEEDED_BY_PAGEOUT) pagedaemon_wakeup(); swap_pager_needflags &= ~(SWAP_FREE_NEEDED|SWAP_FREE_NEEDED_BY_PAGEOUT); } else { /* * release the physical I/O buffer */ relpbuf(bp); /* * finish up input if everything is ok */ if (rv == VM_PAGER_OK) { for (i = 0; i < count; i++) { pmap_clear_modify(VM_PAGE_TO_PHYS(m[i])); m[i]->dirty = 0; m[i]->flags &= ~PG_ZERO; if (i != reqpage) { /* * whether or not to leave the page * activated is up in the air, but we * should put the page on a page queue * somewhere. (it already is in the * object). After some emperical * results, it is best to deactivate * the readahead pages. */ vm_page_deactivate(m[i]); /* * just in case someone was asking for * this page we now tell them that it * is ok to use */ m[i]->valid = VM_PAGE_BITS_ALL; PAGE_WAKEUP(m[i]); } } m[reqpage]->object->last_read = m[count-1]->offset; /* * If we're out of swap space, then attempt to free * some whenever pages are brought in. We must clear * the clean flag so that the page contents will be * preserved. */ if (swap_pager_full) { for (i = 0; i < count; i++) { m[i]->dirty = VM_PAGE_BITS_ALL; } swap_pager_freespace(object, m[0]->offset + paging_offset, count * PAGE_SIZE); } } else { swap_pager_ridpages(m, count, reqpage); } } if (rv == VM_PAGER_OK) { pmap_clear_modify(VM_PAGE_TO_PHYS(m[reqpage])); m[reqpage]->valid = VM_PAGE_BITS_ALL; m[reqpage]->dirty = 0; } return (rv); } int swap_pager_putpages(object, m, count, sync, rtvals) vm_object_t object; vm_page_t *m; int count; boolean_t sync; int *rtvals; { register struct buf *bp; sw_blk_t swb[count]; register int s; int i, j, ix; boolean_t rv; vm_offset_t kva, off, foff; swp_clean_t spc; vm_offset_t paging_offset; int reqaddr[count]; int failed; if (vm_swap_size) no_swap_space = 0; if (no_swap_space) { for (i = 0; i < count; i++) rtvals[i] = VM_PAGER_FAIL; return VM_PAGER_FAIL; } spc = NULL; object = m[0]->object; paging_offset = object->paging_offset; failed = 0; for (j = 0; j < count; j++) { foff = m[j]->offset + paging_offset; ix = swap_pager_block_index(foff); swb[j] = 0; if (ix >= object->un_pager.swp.swp_nblocks) { rtvals[j] = VM_PAGER_FAIL; failed = 1; continue; } else { rtvals[j] = VM_PAGER_OK; } swb[j] = &object->un_pager.swp.swp_blocks[ix]; swb[j]->swb_locked++; if (failed) { rtvals[j] = VM_PAGER_FAIL; continue; } off = swap_pager_block_offset(foff); reqaddr[j] = swb[j]->swb_block[off]; if (reqaddr[j] == SWB_EMPTY) { int blk; int tries; int ntoget; tries = 0; s = splbio(); /* * if any other pages have been allocated in this * block, we only try to get one page. */ for (i = 0; i < SWB_NPAGES; i++) { if (swb[j]->swb_block[i] != SWB_EMPTY) break; } ntoget = (i == SWB_NPAGES) ? SWB_NPAGES : 1; /* * this code is alittle conservative, but works (the * intent of this code is to allocate small chunks for * small objects) */ if ((foff == 0) && ((ntoget * PAGE_SIZE) > object->size)) { ntoget = (object->size + (PAGE_SIZE - 1)) / PAGE_SIZE; } retrygetspace: if (!swap_pager_full && ntoget > 1 && swap_pager_getswapspace(object, ntoget * btodb(PAGE_SIZE), &blk)) { for (i = 0; i < ntoget; i++) { swb[j]->swb_block[i] = blk + btodb(PAGE_SIZE) * i; swb[j]->swb_valid = 0; } reqaddr[j] = swb[j]->swb_block[off]; } else if (!swap_pager_getswapspace(object, btodb(PAGE_SIZE), &swb[j]->swb_block[off])) { /* * if the allocation has failed, we try to * reclaim space and retry. */ if (++tries == 1) { swap_pager_reclaim(); goto retrygetspace; } rtvals[j] = VM_PAGER_AGAIN; failed = 1; swap_pager_full = 1; } else { reqaddr[j] = swb[j]->swb_block[off]; swb[j]->swb_valid &= ~(1 << off); } splx(s); } } /* * search forwards for the last contiguous page to transfer */ failed = 0; for (i = 0; i < count; i++) { if (failed || (reqaddr[i] != reqaddr[0] + i * btodb(PAGE_SIZE)) || (reqaddr[i] / dmmax) != (reqaddr[0] / dmmax) || (rtvals[i] != VM_PAGER_OK)) { failed = 1; if (rtvals[i] == VM_PAGER_OK) rtvals[i] = VM_PAGER_AGAIN; } } for (i = 0; i < count; i++) { if (rtvals[i] != VM_PAGER_OK) { if (swb[i]) --swb[i]->swb_locked; } } for (i = 0; i < count; i++) if (rtvals[i] != VM_PAGER_OK) break; if (i == 0) { return VM_PAGER_AGAIN; } count = i; for (i = 0; i < count; i++) { if (reqaddr[i] == SWB_EMPTY) printf("I/O to empty block????\n"); } /* * For synchronous writes, we clean up all completed async pageouts. */ if (sync == TRUE) { swap_pager_sync(); } kva = 0; /* * get a swap pager clean data structure, block until we get it */ if (swap_pager_free.tqh_first == NULL || swap_pager_free.tqh_first->spc_list.tqe_next == NULL || swap_pager_free.tqh_first->spc_list.tqe_next->spc_list.tqe_next == NULL) { s = splbio(); if (curproc == pageproc) { swap_pager_sync(); #if 0 splx(s); return VM_PAGER_AGAIN; #endif } else pagedaemon_wakeup(); while (swap_pager_free.tqh_first == NULL || swap_pager_free.tqh_first->spc_list.tqe_next == NULL || swap_pager_free.tqh_first->spc_list.tqe_next->spc_list.tqe_next == NULL) { if (curproc == pageproc) { swap_pager_needflags |= SWAP_FREE_NEEDED_BY_PAGEOUT; if((cnt.v_free_count + cnt.v_cache_count) > cnt.v_free_reserved) wakeup(&cnt.v_free_count); } swap_pager_needflags |= SWAP_FREE_NEEDED; tsleep(&swap_pager_free, PVM, "swpfre", 0); if (curproc == pageproc) swap_pager_sync(); else pagedaemon_wakeup(); } splx(s); } spc = swap_pager_free.tqh_first; TAILQ_REMOVE(&swap_pager_free, spc, spc_list); kva = spc->spc_kva; /* * map our page(s) into kva for I/O */ pmap_qenter(kva, m, count); /* * get the base I/O offset into the swap file */ for (i = 0; i < count; i++) { foff = m[i]->offset + paging_offset; off = swap_pager_block_offset(foff); /* * set the valid bit */ swb[i]->swb_valid |= (1 << off); /* * and unlock the data structure */ swb[i]->swb_locked--; } /* * Get a swap buffer header and perform the IO */ bp = spc->spc_bp; bzero(bp, sizeof *bp); bp->b_spc = spc; bp->b_vnbufs.le_next = NOLIST; bp->b_flags = B_BUSY | B_PAGING; bp->b_proc = &proc0; /* XXX (but without B_PHYS set this is ok) */ bp->b_rcred = bp->b_wcred = bp->b_proc->p_ucred; if (bp->b_rcred != NOCRED) crhold(bp->b_rcred); if (bp->b_wcred != NOCRED) crhold(bp->b_wcred); bp->b_data = (caddr_t) kva; bp->b_blkno = reqaddr[0]; pbgetvp(swapdev_vp, bp); bp->b_bcount = PAGE_SIZE * count; bp->b_bufsize = PAGE_SIZE * count; swapdev_vp->v_numoutput++; /* * If this is an async write we set up additional buffer fields and * place a "cleaning" entry on the inuse queue. */ s = splbio(); if (sync == FALSE) { spc->spc_flags = 0; spc->spc_object = object; for (i = 0; i < count; i++) spc->spc_m[i] = m[i]; spc->spc_count = count; /* * the completion routine for async writes */ bp->b_flags |= B_CALL; bp->b_iodone = swap_pager_iodone; bp->b_dirtyoff = 0; bp->b_dirtyend = bp->b_bcount; object->un_pager.swp.swp_poip++; TAILQ_INSERT_TAIL(&swap_pager_inuse, spc, spc_list); } else { object->un_pager.swp.swp_poip++; bp->b_flags |= B_CALL; bp->b_iodone = swap_pager_iodone1; } cnt.v_swapout++; cnt.v_swappgsout += count; /* * perform the I/O */ VOP_STRATEGY(bp); if (sync == FALSE) { if ((bp->b_flags & B_DONE) == B_DONE) { swap_pager_sync(); } splx(s); for (i = 0; i < count; i++) { rtvals[i] = VM_PAGER_PEND; } return VM_PAGER_PEND; } /* * wait for the sync I/O to complete */ while ((bp->b_flags & B_DONE) == 0) { tsleep(bp, PVM, "swwrt", 0); } if (bp->b_flags & B_ERROR) { printf("swap_pager: I/O error - pageout failed; blkno %d, size %d, error %d\n", bp->b_blkno, bp->b_bcount, bp->b_error); rv = VM_PAGER_ERROR; } else { rv = VM_PAGER_OK; } object->un_pager.swp.swp_poip--; if (object->un_pager.swp.swp_poip == 0) wakeup(object); if (bp->b_vp) pbrelvp(bp); if (bp->b_flags & B_WANTED) wakeup(bp); splx(s); /* * remove the mapping for kernel virtual */ pmap_qremove(kva, count); /* * if we have written the page, then indicate that the page is clean. */ if (rv == VM_PAGER_OK) { for (i = 0; i < count; i++) { if (rtvals[i] == VM_PAGER_OK) { pmap_clear_modify(VM_PAGE_TO_PHYS(m[i])); m[i]->dirty = 0; /* * optimization, if a page has been read * during the pageout process, we activate it. */ if ((m[i]->flags & PG_ACTIVE) == 0 && ((m[i]->flags & (PG_WANTED|PG_REFERENCED)) || pmap_is_referenced(VM_PAGE_TO_PHYS(m[i])))) { vm_page_activate(m[i]); } } } } else { for (i = 0; i < count; i++) { rtvals[i] = rv; } } if (bp->b_rcred != NOCRED) crfree(bp->b_rcred); if (bp->b_wcred != NOCRED) crfree(bp->b_wcred); TAILQ_INSERT_TAIL(&swap_pager_free, spc, spc_list); if (swap_pager_needflags & SWAP_FREE_NEEDED) { wakeup(&swap_pager_free); } if (swap_pager_needflags & SWAP_FREE_NEEDED_BY_PAGEOUT) pagedaemon_wakeup(); swap_pager_needflags &= ~(SWAP_FREE_NEEDED|SWAP_FREE_NEEDED_BY_PAGEOUT); return (rv); } void swap_pager_sync() { register swp_clean_t spc, tspc; register int s; tspc = NULL; if (swap_pager_done.tqh_first == NULL) return; for (;;) { s = splbio(); /* * Look up and removal from done list must be done at splbio() * to avoid conflicts with swap_pager_iodone. */ while ((spc = swap_pager_done.tqh_first) != 0) { pmap_qremove(spc->spc_kva, spc->spc_count); swap_pager_finish(spc); TAILQ_REMOVE(&swap_pager_done, spc, spc_list); goto doclean; } /* * No operations done, thats all we can do for now. */ splx(s); break; /* * The desired page was found to be busy earlier in the scan * but has since completed. */ doclean: if (tspc && tspc == spc) { tspc = NULL; } spc->spc_flags = 0; TAILQ_INSERT_TAIL(&swap_pager_free, spc, spc_list); if (swap_pager_needflags & SWAP_FREE_NEEDED) { wakeup(&swap_pager_free); } if( swap_pager_needflags & SWAP_FREE_NEEDED_BY_PAGEOUT) pagedaemon_wakeup(); swap_pager_needflags &= ~(SWAP_FREE_NEEDED|SWAP_FREE_NEEDED_BY_PAGEOUT); splx(s); } return; } void swap_pager_finish(spc) register swp_clean_t spc; { vm_object_t object = spc->spc_m[0]->object; int i; object->paging_in_progress -= spc->spc_count; if ((object->paging_in_progress == 0) && (object->flags & OBJ_PIPWNT)) { object->flags &= ~OBJ_PIPWNT; wakeup(object); } /* * If no error, mark as clean and inform the pmap system. If error, * mark as dirty so we will try again. (XXX could get stuck doing * this, should give up after awhile) */ if (spc->spc_flags & SPC_ERROR) { for (i = 0; i < spc->spc_count; i++) { printf("swap_pager_finish: I/O error, clean of page %lx failed\n", (u_long) VM_PAGE_TO_PHYS(spc->spc_m[i])); } } else { for (i = 0; i < spc->spc_count; i++) { pmap_clear_modify(VM_PAGE_TO_PHYS(spc->spc_m[i])); spc->spc_m[i]->dirty = 0; if ((spc->spc_m[i]->flags & PG_ACTIVE) == 0 && ((spc->spc_m[i]->flags & PG_WANTED) || pmap_is_referenced(VM_PAGE_TO_PHYS(spc->spc_m[i])))) vm_page_activate(spc->spc_m[i]); } } for (i = 0; i < spc->spc_count; i++) { /* * we wakeup any processes that are waiting on these pages. */ PAGE_WAKEUP(spc->spc_m[i]); } nswiodone -= spc->spc_count; return; } /* * swap_pager_iodone */ static void swap_pager_iodone(bp) register struct buf *bp; { register swp_clean_t spc; int s; s = splbio(); spc = (swp_clean_t) bp->b_spc; TAILQ_REMOVE(&swap_pager_inuse, spc, spc_list); TAILQ_INSERT_TAIL(&swap_pager_done, spc, spc_list); if (bp->b_flags & B_ERROR) { spc->spc_flags |= SPC_ERROR; printf("swap_pager: I/O error - async %s failed; blkno %lu, size %ld, error %d\n", (bp->b_flags & B_READ) ? "pagein" : "pageout", (u_long) bp->b_blkno, bp->b_bcount, bp->b_error); } if (bp->b_vp) pbrelvp(bp); if (bp->b_flags & B_WANTED) wakeup(bp); if (bp->b_rcred != NOCRED) crfree(bp->b_rcred); if (bp->b_wcred != NOCRED) crfree(bp->b_wcred); nswiodone += spc->spc_count; if (--spc->spc_object->un_pager.swp.swp_poip == 0) { wakeup(spc->spc_object); } if ((swap_pager_needflags & SWAP_FREE_NEEDED) || swap_pager_inuse.tqh_first == 0) { swap_pager_needflags &= ~SWAP_FREE_NEEDED; wakeup(&swap_pager_free); } if( swap_pager_needflags & SWAP_FREE_NEEDED_BY_PAGEOUT) { swap_pager_needflags &= ~SWAP_FREE_NEEDED_BY_PAGEOUT; pagedaemon_wakeup(); } if (vm_pageout_pages_needed) { wakeup(&vm_pageout_pages_needed); vm_pageout_pages_needed = 0; } if ((swap_pager_inuse.tqh_first == NULL) || ((cnt.v_free_count + cnt.v_cache_count) < cnt.v_free_min && nswiodone + cnt.v_free_count + cnt.v_cache_count >= cnt.v_free_min)) { pagedaemon_wakeup(); } splx(s); } /* * return true if any swap control structures can be allocated */ int swap_pager_ready() { if (swap_pager_free.tqh_first) return 1; else return 0; }