1096e95c0SMatthew Dillon /* 28e7c4729SMatthew Dillon * (MPSAFE) 38e7c4729SMatthew Dillon * 4096e95c0SMatthew Dillon * Copyright (c) 2010 The DragonFly Project. All rights reserved. 5096e95c0SMatthew Dillon * 6096e95c0SMatthew Dillon * This code is derived from software contributed to The DragonFly Project 7096e95c0SMatthew Dillon * by Matthew Dillon <dillon@backplane.com> 8096e95c0SMatthew Dillon * 9096e95c0SMatthew Dillon * Redistribution and use in source and binary forms, with or without 10096e95c0SMatthew Dillon * modification, are permitted provided that the following conditions 11096e95c0SMatthew Dillon * are met: 12096e95c0SMatthew Dillon * 13096e95c0SMatthew Dillon * 1. Redistributions of source code must retain the above copyright 14096e95c0SMatthew Dillon * notice, this list of conditions and the following disclaimer. 15096e95c0SMatthew Dillon * 2. Redistributions in binary form must reproduce the above copyright 16096e95c0SMatthew Dillon * notice, this list of conditions and the following disclaimer in 17096e95c0SMatthew Dillon * the documentation and/or other materials provided with the 18096e95c0SMatthew Dillon * distribution. 19096e95c0SMatthew Dillon * 3. Neither the name of The DragonFly Project nor the names of its 20096e95c0SMatthew Dillon * contributors may be used to endorse or promote products derived 21096e95c0SMatthew Dillon * from this software without specific, prior written permission. 22096e95c0SMatthew Dillon * 23096e95c0SMatthew Dillon * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24096e95c0SMatthew Dillon * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25096e95c0SMatthew Dillon * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 26096e95c0SMatthew Dillon * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 27096e95c0SMatthew Dillon * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 28096e95c0SMatthew Dillon * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 29096e95c0SMatthew Dillon * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 30096e95c0SMatthew Dillon * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 31096e95c0SMatthew Dillon * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 32096e95c0SMatthew Dillon * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 33096e95c0SMatthew Dillon * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34096e95c0SMatthew Dillon * SUCH DAMAGE. 35096e95c0SMatthew Dillon */ 36096e95c0SMatthew Dillon 37096e95c0SMatthew Dillon /* 38096e95c0SMatthew Dillon * Implement the swapcache daemon. When enabled swap is assumed to be 39096e95c0SMatthew Dillon * configured on a fast storage device such as a SSD. Swap is assigned 40096e95c0SMatthew Dillon * to clean vnode-backed pages in the inactive queue, clustered by object 41096e95c0SMatthew Dillon * if possible, and written out. The swap assignment sticks around even 42096e95c0SMatthew Dillon * after the underlying pages have been recycled. 43096e95c0SMatthew Dillon * 44096e95c0SMatthew Dillon * The daemon manages write bandwidth based on sysctl settings to control 45096e95c0SMatthew Dillon * wear on the SSD. 46096e95c0SMatthew Dillon * 47096e95c0SMatthew Dillon * The vnode strategy code will check for the swap assignments and divert 483ffc7051SMatthew Dillon * reads to the swap device when the data is present in the swapcache. 49096e95c0SMatthew Dillon * 50096e95c0SMatthew Dillon * This operates on both regular files and the block device vnodes used by 51096e95c0SMatthew Dillon * filesystems to manage meta-data. 52096e95c0SMatthew Dillon */ 53096e95c0SMatthew Dillon 54096e95c0SMatthew Dillon #include "opt_vm.h" 55096e95c0SMatthew Dillon #include <sys/param.h> 56096e95c0SMatthew Dillon #include <sys/systm.h> 57096e95c0SMatthew Dillon #include <sys/kernel.h> 58096e95c0SMatthew Dillon #include <sys/proc.h> 59096e95c0SMatthew Dillon #include <sys/kthread.h> 60096e95c0SMatthew Dillon #include <sys/resourcevar.h> 61096e95c0SMatthew Dillon #include <sys/signalvar.h> 62096e95c0SMatthew Dillon #include <sys/vnode.h> 63096e95c0SMatthew Dillon #include <sys/vmmeter.h> 64096e95c0SMatthew Dillon #include <sys/sysctl.h> 65497524bfSMatthew Dillon #include <sys/eventhandler.h> 66096e95c0SMatthew Dillon 67096e95c0SMatthew Dillon #include <vm/vm.h> 68096e95c0SMatthew Dillon #include <vm/vm_param.h> 69096e95c0SMatthew Dillon #include <sys/lock.h> 70096e95c0SMatthew Dillon #include <vm/vm_object.h> 71096e95c0SMatthew Dillon #include <vm/vm_page.h> 72096e95c0SMatthew Dillon #include <vm/vm_map.h> 73096e95c0SMatthew Dillon #include <vm/vm_pageout.h> 74096e95c0SMatthew Dillon #include <vm/vm_pager.h> 75096e95c0SMatthew Dillon #include <vm/swap_pager.h> 76096e95c0SMatthew Dillon #include <vm/vm_extern.h> 77096e95c0SMatthew Dillon 78096e95c0SMatthew Dillon #include <sys/thread2.h> 79b12defdcSMatthew Dillon #include <sys/spinlock2.h> 80096e95c0SMatthew Dillon #include <vm/vm_page2.h> 81096e95c0SMatthew Dillon 82096e95c0SMatthew Dillon /* the kernel process "vm_pageout"*/ 83aabd5ce8SMatthew Dillon static int vm_swapcached_flush (vm_page_t m, int isblkdev); 843ffc7051SMatthew Dillon static int vm_swapcache_test(vm_page_t m); 8500a3fdcaSMatthew Dillon static void vm_swapcache_writing(vm_page_t marker); 8600a3fdcaSMatthew Dillon static void vm_swapcache_cleaning(vm_object_t marker); 87f5f6d247SMatthew Dillon static void vm_swapcache_movemarker(vm_object_t marker, vm_object_t object); 88096e95c0SMatthew Dillon struct thread *swapcached_thread; 89096e95c0SMatthew Dillon 90096e95c0SMatthew Dillon SYSCTL_NODE(_vm, OID_AUTO, swapcache, CTLFLAG_RW, NULL, NULL); 91096e95c0SMatthew Dillon 92c504e38eSMatthew Dillon int vm_swapcache_read_enable; 93e527fb6bSMatthew Dillon int vm_swapcache_inactive_heuristic; 94096e95c0SMatthew Dillon static int vm_swapcache_sleep; 95*0bf81261SMatthew Dillon static int vm_swapcache_maxscan = 256 * 4; 961e5196f0SMatthew Dillon static int vm_swapcache_maxlaunder = 256; 97096e95c0SMatthew Dillon static int vm_swapcache_data_enable = 0; 98096e95c0SMatthew Dillon static int vm_swapcache_meta_enable = 0; 99e9b56058SMatthew Dillon static int vm_swapcache_maxswappct = 75; 100e527fb6bSMatthew Dillon static int vm_swapcache_hysteresis; 101bfa86281SMatthew Dillon int vm_swapcache_use_chflags = 1; /* require chflags cache */ 1023ffc7051SMatthew Dillon static int64_t vm_swapcache_minburst = 10000000LL; /* 10MB */ 1033ffc7051SMatthew Dillon static int64_t vm_swapcache_curburst = 4000000000LL; /* 4G after boot */ 1043ffc7051SMatthew Dillon static int64_t vm_swapcache_maxburst = 2000000000LL; /* 2G nominal max */ 1053ffc7051SMatthew Dillon static int64_t vm_swapcache_accrate = 100000LL; /* 100K/s */ 106096e95c0SMatthew Dillon static int64_t vm_swapcache_write_count; 1073ffc7051SMatthew Dillon static int64_t vm_swapcache_maxfilesize; 108f5f6d247SMatthew Dillon static int64_t vm_swapcache_cleanperobj = 16*1024*1024; 109096e95c0SMatthew Dillon 110096e95c0SMatthew Dillon SYSCTL_INT(_vm_swapcache, OID_AUTO, maxlaunder, 111096e95c0SMatthew Dillon CTLFLAG_RW, &vm_swapcache_maxlaunder, 0, ""); 112*0bf81261SMatthew Dillon SYSCTL_INT(_vm_swapcache, OID_AUTO, maxscan, 113*0bf81261SMatthew Dillon CTLFLAG_RW, &vm_swapcache_maxscan, 0, ""); 114c504e38eSMatthew Dillon 115096e95c0SMatthew Dillon SYSCTL_INT(_vm_swapcache, OID_AUTO, data_enable, 116096e95c0SMatthew Dillon CTLFLAG_RW, &vm_swapcache_data_enable, 0, ""); 117096e95c0SMatthew Dillon SYSCTL_INT(_vm_swapcache, OID_AUTO, meta_enable, 118096e95c0SMatthew Dillon CTLFLAG_RW, &vm_swapcache_meta_enable, 0, ""); 119c504e38eSMatthew Dillon SYSCTL_INT(_vm_swapcache, OID_AUTO, read_enable, 120c504e38eSMatthew Dillon CTLFLAG_RW, &vm_swapcache_read_enable, 0, ""); 121e9b56058SMatthew Dillon SYSCTL_INT(_vm_swapcache, OID_AUTO, maxswappct, 122e9b56058SMatthew Dillon CTLFLAG_RW, &vm_swapcache_maxswappct, 0, ""); 123e527fb6bSMatthew Dillon SYSCTL_INT(_vm_swapcache, OID_AUTO, hysteresis, 124e527fb6bSMatthew Dillon CTLFLAG_RW, &vm_swapcache_hysteresis, 0, ""); 125e9b56058SMatthew Dillon SYSCTL_INT(_vm_swapcache, OID_AUTO, use_chflags, 126e9b56058SMatthew Dillon CTLFLAG_RW, &vm_swapcache_use_chflags, 0, ""); 127c504e38eSMatthew Dillon 1283ffc7051SMatthew Dillon SYSCTL_QUAD(_vm_swapcache, OID_AUTO, minburst, 1293ffc7051SMatthew Dillon CTLFLAG_RW, &vm_swapcache_minburst, 0, ""); 130c504e38eSMatthew Dillon SYSCTL_QUAD(_vm_swapcache, OID_AUTO, curburst, 131c504e38eSMatthew Dillon CTLFLAG_RW, &vm_swapcache_curburst, 0, ""); 132c504e38eSMatthew Dillon SYSCTL_QUAD(_vm_swapcache, OID_AUTO, maxburst, 133c504e38eSMatthew Dillon CTLFLAG_RW, &vm_swapcache_maxburst, 0, ""); 1343ffc7051SMatthew Dillon SYSCTL_QUAD(_vm_swapcache, OID_AUTO, maxfilesize, 1353ffc7051SMatthew Dillon CTLFLAG_RW, &vm_swapcache_maxfilesize, 0, ""); 136c504e38eSMatthew Dillon SYSCTL_QUAD(_vm_swapcache, OID_AUTO, accrate, 137c504e38eSMatthew Dillon CTLFLAG_RW, &vm_swapcache_accrate, 0, ""); 138096e95c0SMatthew Dillon SYSCTL_QUAD(_vm_swapcache, OID_AUTO, write_count, 139096e95c0SMatthew Dillon CTLFLAG_RW, &vm_swapcache_write_count, 0, ""); 140f5f6d247SMatthew Dillon SYSCTL_QUAD(_vm_swapcache, OID_AUTO, cleanperobj, 141f5f6d247SMatthew Dillon CTLFLAG_RW, &vm_swapcache_cleanperobj, 0, ""); 142096e95c0SMatthew Dillon 143e9b56058SMatthew Dillon #define SWAPMAX(adj) \ 144e9b56058SMatthew Dillon ((int64_t)vm_swap_max * (vm_swapcache_maxswappct + (adj)) / 100) 145e9b56058SMatthew Dillon 146096e95c0SMatthew Dillon /* 147497524bfSMatthew Dillon * When shutting down the machine we want to stop swapcache operation 148497524bfSMatthew Dillon * immediately so swap is not accessed after devices have been shuttered. 149497524bfSMatthew Dillon */ 150497524bfSMatthew Dillon static void 151497524bfSMatthew Dillon shutdown_swapcache(void *arg __unused) 152497524bfSMatthew Dillon { 153497524bfSMatthew Dillon vm_swapcache_read_enable = 0; 154497524bfSMatthew Dillon vm_swapcache_data_enable = 0; 155497524bfSMatthew Dillon vm_swapcache_meta_enable = 0; 156497524bfSMatthew Dillon wakeup(&vm_swapcache_sleep); /* shortcut 5-second wait */ 157497524bfSMatthew Dillon } 158497524bfSMatthew Dillon 159497524bfSMatthew Dillon /* 160096e95c0SMatthew Dillon * vm_swapcached is the high level pageout daemon. 1618e7c4729SMatthew Dillon * 1628e7c4729SMatthew Dillon * No requirements. 163096e95c0SMatthew Dillon */ 164096e95c0SMatthew Dillon static void 165cd8ab232SMatthew Dillon vm_swapcached_thread(void) 166096e95c0SMatthew Dillon { 16700a3fdcaSMatthew Dillon enum { SWAPC_WRITING, SWAPC_CLEANING } state = SWAPC_WRITING; 1683ffc7051SMatthew Dillon enum { SWAPB_BURSTING, SWAPB_RECOVERING } burst = SWAPB_BURSTING; 16951c99c61SMatthew Dillon static struct vm_page page_marker[PQ_L2_SIZE]; 170027193ebSMatthew Dillon static struct vm_object object_marker; 171027193ebSMatthew Dillon int q; 172096e95c0SMatthew Dillon 173096e95c0SMatthew Dillon /* 174096e95c0SMatthew Dillon * Thread setup 175096e95c0SMatthew Dillon */ 176096e95c0SMatthew Dillon curthread->td_flags |= TDF_SYSTHREAD; 177497524bfSMatthew Dillon EVENTHANDLER_REGISTER(shutdown_pre_sync, shutdown_kproc, 178497524bfSMatthew Dillon swapcached_thread, SHUTDOWN_PRI_FIRST); 179497524bfSMatthew Dillon EVENTHANDLER_REGISTER(shutdown_pre_sync, shutdown_swapcache, 180497524bfSMatthew Dillon NULL, SHUTDOWN_PRI_SECOND); 181096e95c0SMatthew Dillon 182096e95c0SMatthew Dillon /* 18300a3fdcaSMatthew Dillon * Initialize our marker for the inactive scan (SWAPC_WRITING) 184096e95c0SMatthew Dillon */ 18500a3fdcaSMatthew Dillon bzero(&page_marker, sizeof(page_marker)); 18651c99c61SMatthew Dillon for (q = 0; q < PQ_L2_SIZE; ++q) { 187027193ebSMatthew Dillon page_marker[q].flags = PG_BUSY | PG_FICTITIOUS | PG_MARKER; 188027193ebSMatthew Dillon page_marker[q].queue = PQ_INACTIVE + q; 189027193ebSMatthew Dillon page_marker[q].pc = q; 190027193ebSMatthew Dillon page_marker[q].wire_count = 1; 191027193ebSMatthew Dillon vm_page_queues_spin_lock(PQ_INACTIVE + q); 192027193ebSMatthew Dillon TAILQ_INSERT_HEAD( 193027193ebSMatthew Dillon &vm_page_queues[PQ_INACTIVE + q].pl, 194027193ebSMatthew Dillon &page_marker[q], pageq); 195027193ebSMatthew Dillon vm_page_queues_spin_unlock(PQ_INACTIVE + q); 196027193ebSMatthew Dillon } 197b12defdcSMatthew Dillon 198e527fb6bSMatthew Dillon vm_swapcache_hysteresis = vmstats.v_inactive_target / 2; 199e527fb6bSMatthew Dillon vm_swapcache_inactive_heuristic = -vm_swapcache_hysteresis; 200096e95c0SMatthew Dillon 20100a3fdcaSMatthew Dillon /* 20200a3fdcaSMatthew Dillon * Initialize our marker for the vm_object scan (SWAPC_CLEANING) 20300a3fdcaSMatthew Dillon */ 20400a3fdcaSMatthew Dillon bzero(&object_marker, sizeof(object_marker)); 20500a3fdcaSMatthew Dillon object_marker.type = OBJT_MARKER; 2062de4f77eSMatthew Dillon lwkt_gettoken(&vmobj_token); 20700a3fdcaSMatthew Dillon TAILQ_INSERT_HEAD(&vm_object_list, &object_marker, object_list); 2082de4f77eSMatthew Dillon lwkt_reltoken(&vmobj_token); 209096e95c0SMatthew Dillon 210096e95c0SMatthew Dillon for (;;) { 211096e95c0SMatthew Dillon /* 212497524bfSMatthew Dillon * Handle shutdown 213497524bfSMatthew Dillon */ 214497524bfSMatthew Dillon kproc_suspend_loop(); 215497524bfSMatthew Dillon 216497524bfSMatthew Dillon /* 2173da46bd7SMatthew Dillon * Check every 5 seconds when not enabled or if no swap 2183da46bd7SMatthew Dillon * is present. 219096e95c0SMatthew Dillon */ 2203da46bd7SMatthew Dillon if ((vm_swapcache_data_enable == 0 && 2213da46bd7SMatthew Dillon vm_swapcache_meta_enable == 0) || 2223da46bd7SMatthew Dillon vm_swap_max == 0) { 223096e95c0SMatthew Dillon tsleep(&vm_swapcache_sleep, 0, "csleep", hz * 5); 224096e95c0SMatthew Dillon continue; 225096e95c0SMatthew Dillon } 226c504e38eSMatthew Dillon 227c504e38eSMatthew Dillon /* 2283da46bd7SMatthew Dillon * Polling rate when enabled is approximately 10 hz. 229c504e38eSMatthew Dillon */ 230c504e38eSMatthew Dillon tsleep(&vm_swapcache_sleep, 0, "csleep", hz / 10); 23100a3fdcaSMatthew Dillon 23200a3fdcaSMatthew Dillon /* 23300a3fdcaSMatthew Dillon * State hysteresis. Generate write activity up to 75% of 23400a3fdcaSMatthew Dillon * swap, then clean out swap assignments down to 70%, then 23500a3fdcaSMatthew Dillon * repeat. 23600a3fdcaSMatthew Dillon */ 23700a3fdcaSMatthew Dillon if (state == SWAPC_WRITING) { 238e9b56058SMatthew Dillon if (vm_swap_cache_use > SWAPMAX(0)) 23900a3fdcaSMatthew Dillon state = SWAPC_CLEANING; 24000a3fdcaSMatthew Dillon } else { 24108fb7a9dSMatthew Dillon if (vm_swap_cache_use < SWAPMAX(-10)) 24200a3fdcaSMatthew Dillon state = SWAPC_WRITING; 24300a3fdcaSMatthew Dillon } 24400a3fdcaSMatthew Dillon 24500a3fdcaSMatthew Dillon /* 24600a3fdcaSMatthew Dillon * We are allowed to continue accumulating burst value 2473ffc7051SMatthew Dillon * in either state. Allow the user to set curburst > maxburst 2483ffc7051SMatthew Dillon * for the initial load-in. 24900a3fdcaSMatthew Dillon */ 2503ffc7051SMatthew Dillon if (vm_swapcache_curburst < vm_swapcache_maxburst) { 251c504e38eSMatthew Dillon vm_swapcache_curburst += vm_swapcache_accrate / 10; 252c504e38eSMatthew Dillon if (vm_swapcache_curburst > vm_swapcache_maxburst) 253c504e38eSMatthew Dillon vm_swapcache_curburst = vm_swapcache_maxburst; 2543ffc7051SMatthew Dillon } 255c504e38eSMatthew Dillon 256c504e38eSMatthew Dillon /* 25700a3fdcaSMatthew Dillon * We don't want to nickle-and-dime the scan as that will 25800a3fdcaSMatthew Dillon * create unnecessary fragmentation. The minimum burst 25900a3fdcaSMatthew Dillon * is one-seconds worth of accumulation. 260c504e38eSMatthew Dillon */ 26100a3fdcaSMatthew Dillon if (state == SWAPC_WRITING) { 2623ffc7051SMatthew Dillon if (vm_swapcache_curburst >= vm_swapcache_accrate) { 2633ffc7051SMatthew Dillon if (burst == SWAPB_BURSTING) { 26451c99c61SMatthew Dillon for (q = 0; q < PQ_L2_SIZE; ++q) { 265027193ebSMatthew Dillon vm_swapcache_writing( 266027193ebSMatthew Dillon &page_marker[q]); 267027193ebSMatthew Dillon } 2683ffc7051SMatthew Dillon if (vm_swapcache_curburst <= 0) 2693ffc7051SMatthew Dillon burst = SWAPB_RECOVERING; 2703ffc7051SMatthew Dillon } else if (vm_swapcache_curburst > 2713ffc7051SMatthew Dillon vm_swapcache_minburst) { 27251c99c61SMatthew Dillon for (q = 0; q < PQ_L2_SIZE; ++q) { 273027193ebSMatthew Dillon vm_swapcache_writing( 274027193ebSMatthew Dillon &page_marker[q]); 275027193ebSMatthew Dillon } 2763ffc7051SMatthew Dillon burst = SWAPB_BURSTING; 2773ffc7051SMatthew Dillon } 2783ffc7051SMatthew Dillon } 27900a3fdcaSMatthew Dillon } else { 28000a3fdcaSMatthew Dillon vm_swapcache_cleaning(&object_marker); 28100a3fdcaSMatthew Dillon } 28200a3fdcaSMatthew Dillon } 283eccc8ca1SMatthew Dillon 284eccc8ca1SMatthew Dillon /* 285eccc8ca1SMatthew Dillon * Cleanup (NOT REACHED) 286eccc8ca1SMatthew Dillon */ 28751c99c61SMatthew Dillon for (q = 0; q < PQ_L2_SIZE; ++q) { 288027193ebSMatthew Dillon vm_page_queues_spin_lock(PQ_INACTIVE + q); 289027193ebSMatthew Dillon TAILQ_REMOVE( 290027193ebSMatthew Dillon &vm_page_queues[PQ_INACTIVE + q].pl, 291027193ebSMatthew Dillon &page_marker[q], pageq); 292027193ebSMatthew Dillon vm_page_queues_spin_unlock(PQ_INACTIVE + q); 293027193ebSMatthew Dillon } 294eccc8ca1SMatthew Dillon 2952de4f77eSMatthew Dillon lwkt_gettoken(&vmobj_token); 29600a3fdcaSMatthew Dillon TAILQ_REMOVE(&vm_object_list, &object_marker, object_list); 2972de4f77eSMatthew Dillon lwkt_reltoken(&vmobj_token); 29800a3fdcaSMatthew Dillon } 299096e95c0SMatthew Dillon 300cd8ab232SMatthew Dillon static struct kproc_desc swpc_kp = { 301cd8ab232SMatthew Dillon "swapcached", 302cd8ab232SMatthew Dillon vm_swapcached_thread, 303cd8ab232SMatthew Dillon &swapcached_thread 304cd8ab232SMatthew Dillon }; 305cd8ab232SMatthew Dillon SYSINIT(swapcached, SI_SUB_KTHREAD_PAGE, SI_ORDER_SECOND, kproc_start, &swpc_kp) 306cd8ab232SMatthew Dillon 30700a3fdcaSMatthew Dillon static void 30800a3fdcaSMatthew Dillon vm_swapcache_writing(vm_page_t marker) 30900a3fdcaSMatthew Dillon { 31000a3fdcaSMatthew Dillon vm_object_t object; 31100a3fdcaSMatthew Dillon struct vnode *vp; 31200a3fdcaSMatthew Dillon vm_page_t m; 31300a3fdcaSMatthew Dillon int count; 314*0bf81261SMatthew Dillon int scount; 315aabd5ce8SMatthew Dillon int isblkdev; 316096e95c0SMatthew Dillon 317096e95c0SMatthew Dillon /* 318fdc53cc7SMatthew Dillon * Deal with an overflow of the heuristic counter or if the user 319fdc53cc7SMatthew Dillon * manually changes the hysteresis. 320fdc53cc7SMatthew Dillon * 321e527fb6bSMatthew Dillon * Try to avoid small incremental pageouts by waiting for enough 322e527fb6bSMatthew Dillon * pages to buildup in the inactive queue to hopefully get a good 323e527fb6bSMatthew Dillon * burst in. This heuristic is bumped by the VM system and reset 324e527fb6bSMatthew Dillon * when our scan hits the end of the queue. 325e527fb6bSMatthew Dillon */ 326fdc53cc7SMatthew Dillon if (vm_swapcache_inactive_heuristic < -vm_swapcache_hysteresis) 327fdc53cc7SMatthew Dillon vm_swapcache_inactive_heuristic = -vm_swapcache_hysteresis; 328e527fb6bSMatthew Dillon if (vm_swapcache_inactive_heuristic < 0) 329e527fb6bSMatthew Dillon return; 330e527fb6bSMatthew Dillon 331e527fb6bSMatthew Dillon /* 332096e95c0SMatthew Dillon * Scan the inactive queue from our marker to locate 333096e95c0SMatthew Dillon * suitable pages to push to the swap cache. 334096e95c0SMatthew Dillon * 335096e95c0SMatthew Dillon * We are looking for clean vnode-backed pages. 336096e95c0SMatthew Dillon */ 33700a3fdcaSMatthew Dillon count = vm_swapcache_maxlaunder; 338*0bf81261SMatthew Dillon scount = vm_swapcache_maxscan; 33900a3fdcaSMatthew Dillon 340027193ebSMatthew Dillon vm_page_queues_spin_lock(marker->queue); 341*0bf81261SMatthew Dillon while ((m = TAILQ_NEXT(marker, pageq)) != NULL && 342*0bf81261SMatthew Dillon count > 0 && scount-- > 0) { 343027193ebSMatthew Dillon KKASSERT(m->queue == marker->queue); 344b12defdcSMatthew Dillon 345b12defdcSMatthew Dillon if (vm_swapcache_curburst < 0) 346b12defdcSMatthew Dillon break; 347027193ebSMatthew Dillon TAILQ_REMOVE( 348027193ebSMatthew Dillon &vm_page_queues[marker->queue].pl, marker, pageq); 349027193ebSMatthew Dillon TAILQ_INSERT_AFTER( 350027193ebSMatthew Dillon &vm_page_queues[marker->queue].pl, m, marker, pageq); 351f5f6d247SMatthew Dillon 352f5f6d247SMatthew Dillon /* 353f5f6d247SMatthew Dillon * Ignore markers and ignore pages that already have a swap 354f5f6d247SMatthew Dillon * assignment. 355f5f6d247SMatthew Dillon */ 356*0bf81261SMatthew Dillon if (m->flags & (PG_MARKER | PG_SWAPPED)) 357096e95c0SMatthew Dillon continue; 358b12defdcSMatthew Dillon if (vm_page_busy_try(m, TRUE)) 359096e95c0SMatthew Dillon continue; 360027193ebSMatthew Dillon vm_page_queues_spin_unlock(marker->queue); 361b12defdcSMatthew Dillon 362b12defdcSMatthew Dillon if ((object = m->object) == NULL) { 363b12defdcSMatthew Dillon vm_page_wakeup(m); 364027193ebSMatthew Dillon vm_page_queues_spin_lock(marker->queue); 365b12defdcSMatthew Dillon continue; 366b12defdcSMatthew Dillon } 367b12defdcSMatthew Dillon vm_object_hold(object); 368b12defdcSMatthew Dillon if (m->object != object) { 369b12defdcSMatthew Dillon vm_object_drop(object); 370b12defdcSMatthew Dillon vm_page_wakeup(m); 371027193ebSMatthew Dillon vm_page_queues_spin_lock(marker->queue); 372b12defdcSMatthew Dillon continue; 373b12defdcSMatthew Dillon } 374b12defdcSMatthew Dillon if (vm_swapcache_test(m)) { 375b12defdcSMatthew Dillon vm_object_drop(object); 376b12defdcSMatthew Dillon vm_page_wakeup(m); 377027193ebSMatthew Dillon vm_page_queues_spin_lock(marker->queue); 378b12defdcSMatthew Dillon continue; 379b12defdcSMatthew Dillon } 380b12defdcSMatthew Dillon 381c504e38eSMatthew Dillon vp = object->handle; 382b12defdcSMatthew Dillon if (vp == NULL) { 383b12defdcSMatthew Dillon vm_object_drop(object); 384b12defdcSMatthew Dillon vm_page_wakeup(m); 385027193ebSMatthew Dillon vm_page_queues_spin_lock(marker->queue); 386c504e38eSMatthew Dillon continue; 387b12defdcSMatthew Dillon } 388d3070b8dSMatthew Dillon 389c504e38eSMatthew Dillon switch(vp->v_type) { 390c504e38eSMatthew Dillon case VREG: 391e9b56058SMatthew Dillon /* 392bfa86281SMatthew Dillon * PG_NOTMETA generically means 'don't swapcache this', 393bfa86281SMatthew Dillon * and HAMMER will set this for regular data buffers 394bfa86281SMatthew Dillon * (and leave it unset for meta-data buffers) as 395bfa86281SMatthew Dillon * appropriate when double buffering is enabled. 396bfa86281SMatthew Dillon */ 397b12defdcSMatthew Dillon if (m->flags & PG_NOTMETA) { 398b12defdcSMatthew Dillon vm_object_drop(object); 399b12defdcSMatthew Dillon vm_page_wakeup(m); 400027193ebSMatthew Dillon vm_page_queues_spin_lock(marker->queue); 401bfa86281SMatthew Dillon continue; 402b12defdcSMatthew Dillon } 403bfa86281SMatthew Dillon 404bfa86281SMatthew Dillon /* 405e9b56058SMatthew Dillon * If data_enable is 0 do not try to swapcache data. 406e9b56058SMatthew Dillon * If use_chflags is set then only swapcache data for 407e9b56058SMatthew Dillon * VSWAPCACHE marked vnodes, otherwise any vnode. 408e9b56058SMatthew Dillon */ 409e9b56058SMatthew Dillon if (vm_swapcache_data_enable == 0 || 410e9b56058SMatthew Dillon ((vp->v_flag & VSWAPCACHE) == 0 && 411e9b56058SMatthew Dillon vm_swapcache_use_chflags)) { 412b12defdcSMatthew Dillon vm_object_drop(object); 413b12defdcSMatthew Dillon vm_page_wakeup(m); 414027193ebSMatthew Dillon vm_page_queues_spin_lock(marker->queue); 415c504e38eSMatthew Dillon continue; 416e9b56058SMatthew Dillon } 417d3070b8dSMatthew Dillon if (vm_swapcache_maxfilesize && 418d3070b8dSMatthew Dillon object->size > 419d3070b8dSMatthew Dillon (vm_swapcache_maxfilesize >> PAGE_SHIFT)) { 420b12defdcSMatthew Dillon vm_object_drop(object); 421b12defdcSMatthew Dillon vm_page_wakeup(m); 422027193ebSMatthew Dillon vm_page_queues_spin_lock(marker->queue); 423d3070b8dSMatthew Dillon continue; 424d3070b8dSMatthew Dillon } 425aabd5ce8SMatthew Dillon isblkdev = 0; 426c504e38eSMatthew Dillon break; 427c504e38eSMatthew Dillon case VCHR: 428aabd5ce8SMatthew Dillon /* 429bfa86281SMatthew Dillon * PG_NOTMETA generically means 'don't swapcache this', 430bfa86281SMatthew Dillon * and HAMMER will set this for regular data buffers 431bfa86281SMatthew Dillon * (and leave it unset for meta-data buffers) as 432bfa86281SMatthew Dillon * appropriate when double buffering is enabled. 433aabd5ce8SMatthew Dillon */ 434b12defdcSMatthew Dillon if (m->flags & PG_NOTMETA) { 435b12defdcSMatthew Dillon vm_object_drop(object); 436b12defdcSMatthew Dillon vm_page_wakeup(m); 437027193ebSMatthew Dillon vm_page_queues_spin_lock(marker->queue); 438aabd5ce8SMatthew Dillon continue; 439b12defdcSMatthew Dillon } 440b12defdcSMatthew Dillon if (vm_swapcache_meta_enable == 0) { 441b12defdcSMatthew Dillon vm_object_drop(object); 442b12defdcSMatthew Dillon vm_page_wakeup(m); 443027193ebSMatthew Dillon vm_page_queues_spin_lock(marker->queue); 444c504e38eSMatthew Dillon continue; 445b12defdcSMatthew Dillon } 446aabd5ce8SMatthew Dillon isblkdev = 1; 447c504e38eSMatthew Dillon break; 448c504e38eSMatthew Dillon default: 449b12defdcSMatthew Dillon vm_object_drop(object); 450b12defdcSMatthew Dillon vm_page_wakeup(m); 451027193ebSMatthew Dillon vm_page_queues_spin_lock(marker->queue); 452c504e38eSMatthew Dillon continue; 453c504e38eSMatthew Dillon } 454096e95c0SMatthew Dillon 455096e95c0SMatthew Dillon 456096e95c0SMatthew Dillon /* 4573ffc7051SMatthew Dillon * Assign swap and initiate I/O. 4583ffc7051SMatthew Dillon * 4593ffc7051SMatthew Dillon * (adjust for the --count which also occurs in the loop) 460096e95c0SMatthew Dillon */ 461*0bf81261SMatthew Dillon count -= vm_swapcached_flush(m, isblkdev); 462096e95c0SMatthew Dillon 463096e95c0SMatthew Dillon /* 464096e95c0SMatthew Dillon * Setup for next loop using marker. 465096e95c0SMatthew Dillon */ 466b12defdcSMatthew Dillon vm_object_drop(object); 467027193ebSMatthew Dillon vm_page_queues_spin_lock(marker->queue); 468096e95c0SMatthew Dillon } 4691e5196f0SMatthew Dillon 4701e5196f0SMatthew Dillon /* 471b12defdcSMatthew Dillon * The marker could wind up at the end, which is ok. If we hit the 472b12defdcSMatthew Dillon * end of the list adjust the heuristic. 4731e5196f0SMatthew Dillon * 4741e5196f0SMatthew Dillon * Earlier inactive pages that were dirty and become clean 4751e5196f0SMatthew Dillon * are typically moved to the end of PQ_INACTIVE by virtue 4761e5196f0SMatthew Dillon * of vfs_vmio_release() when they become unwired from the 4771e5196f0SMatthew Dillon * buffer cache. 4781e5196f0SMatthew Dillon */ 479b12defdcSMatthew Dillon if (m == NULL) 480e527fb6bSMatthew Dillon vm_swapcache_inactive_heuristic = -vm_swapcache_hysteresis; 481027193ebSMatthew Dillon vm_page_queues_spin_unlock(marker->queue); 482096e95c0SMatthew Dillon } 483096e95c0SMatthew Dillon 484096e95c0SMatthew Dillon /* 485b12defdcSMatthew Dillon * Flush the specified page using the swap_pager. The page 486b12defdcSMatthew Dillon * must be busied by the caller and its disposition will become 487b12defdcSMatthew Dillon * the responsibility of this function. 4883ffc7051SMatthew Dillon * 4893ffc7051SMatthew Dillon * Try to collect surrounding pages, including pages which may 4903ffc7051SMatthew Dillon * have already been assigned swap. Try to cluster within a 4913ffc7051SMatthew Dillon * contiguous aligned SMAP_META_PAGES (typ 16 x PAGE_SIZE) block 4923ffc7051SMatthew Dillon * to match what swap_pager_putpages() can do. 4933ffc7051SMatthew Dillon * 4943ffc7051SMatthew Dillon * We also want to try to match against the buffer cache blocksize 4953ffc7051SMatthew Dillon * but we don't really know what it is here. Since the buffer cache 4963ffc7051SMatthew Dillon * wires and unwires pages in groups the fact that we skip wired pages 4973ffc7051SMatthew Dillon * should be sufficient. 4983ffc7051SMatthew Dillon * 4993ffc7051SMatthew Dillon * Returns a count of pages we might have flushed (minimum 1) 500096e95c0SMatthew Dillon */ 501096e95c0SMatthew Dillon static 5023ffc7051SMatthew Dillon int 503aabd5ce8SMatthew Dillon vm_swapcached_flush(vm_page_t m, int isblkdev) 504096e95c0SMatthew Dillon { 505096e95c0SMatthew Dillon vm_object_t object; 5063ffc7051SMatthew Dillon vm_page_t marray[SWAP_META_PAGES]; 5073ffc7051SMatthew Dillon vm_pindex_t basei; 5083ffc7051SMatthew Dillon int rtvals[SWAP_META_PAGES]; 5093ffc7051SMatthew Dillon int x; 5103ffc7051SMatthew Dillon int i; 5113ffc7051SMatthew Dillon int j; 5123ffc7051SMatthew Dillon int count; 513b12defdcSMatthew Dillon int error; 514096e95c0SMatthew Dillon 515096e95c0SMatthew Dillon vm_page_io_start(m); 516096e95c0SMatthew Dillon vm_page_protect(m, VM_PROT_READ); 517096e95c0SMatthew Dillon object = m->object; 518b12defdcSMatthew Dillon vm_object_hold(object); 519096e95c0SMatthew Dillon 5203ffc7051SMatthew Dillon /* 5213ffc7051SMatthew Dillon * Try to cluster around (m), keeping in mind that the swap pager 5223ffc7051SMatthew Dillon * can only do SMAP_META_PAGES worth of continguous write. 5233ffc7051SMatthew Dillon */ 5243ffc7051SMatthew Dillon x = (int)m->pindex & SWAP_META_MASK; 5253ffc7051SMatthew Dillon marray[x] = m; 5263ffc7051SMatthew Dillon basei = m->pindex; 527b12defdcSMatthew Dillon vm_page_wakeup(m); 5283ffc7051SMatthew Dillon 5293ffc7051SMatthew Dillon for (i = x - 1; i >= 0; --i) { 530b12defdcSMatthew Dillon m = vm_page_lookup_busy_try(object, basei - x + i, 531b12defdcSMatthew Dillon TRUE, &error); 532b12defdcSMatthew Dillon if (error || m == NULL) 5333ffc7051SMatthew Dillon break; 534b12defdcSMatthew Dillon if (vm_swapcache_test(m)) { 535b12defdcSMatthew Dillon vm_page_wakeup(m); 5363ffc7051SMatthew Dillon break; 537b12defdcSMatthew Dillon } 538b12defdcSMatthew Dillon if (isblkdev && (m->flags & PG_NOTMETA)) { 539b12defdcSMatthew Dillon vm_page_wakeup(m); 540aabd5ce8SMatthew Dillon break; 541b12defdcSMatthew Dillon } 5423ffc7051SMatthew Dillon vm_page_io_start(m); 5433ffc7051SMatthew Dillon vm_page_protect(m, VM_PROT_READ); 5443ffc7051SMatthew Dillon if (m->queue - m->pc == PQ_CACHE) { 5453ffc7051SMatthew Dillon vm_page_unqueue_nowakeup(m); 5463ffc7051SMatthew Dillon vm_page_deactivate(m); 5473ffc7051SMatthew Dillon } 5483ffc7051SMatthew Dillon marray[i] = m; 549b12defdcSMatthew Dillon vm_page_wakeup(m); 5503ffc7051SMatthew Dillon } 5513ffc7051SMatthew Dillon ++i; 5523ffc7051SMatthew Dillon 5533ffc7051SMatthew Dillon for (j = x + 1; j < SWAP_META_PAGES; ++j) { 554b12defdcSMatthew Dillon m = vm_page_lookup_busy_try(object, basei - x + j, 555b12defdcSMatthew Dillon TRUE, &error); 556b12defdcSMatthew Dillon if (error || m == NULL) 5573ffc7051SMatthew Dillon break; 558b12defdcSMatthew Dillon if (vm_swapcache_test(m)) { 559b12defdcSMatthew Dillon vm_page_wakeup(m); 5603ffc7051SMatthew Dillon break; 561b12defdcSMatthew Dillon } 562b12defdcSMatthew Dillon if (isblkdev && (m->flags & PG_NOTMETA)) { 563b12defdcSMatthew Dillon vm_page_wakeup(m); 564aabd5ce8SMatthew Dillon break; 565b12defdcSMatthew Dillon } 5663ffc7051SMatthew Dillon vm_page_io_start(m); 5673ffc7051SMatthew Dillon vm_page_protect(m, VM_PROT_READ); 5683ffc7051SMatthew Dillon if (m->queue - m->pc == PQ_CACHE) { 5693ffc7051SMatthew Dillon vm_page_unqueue_nowakeup(m); 5703ffc7051SMatthew Dillon vm_page_deactivate(m); 5713ffc7051SMatthew Dillon } 5723ffc7051SMatthew Dillon marray[j] = m; 573b12defdcSMatthew Dillon vm_page_wakeup(m); 5743ffc7051SMatthew Dillon } 5753ffc7051SMatthew Dillon 5763ffc7051SMatthew Dillon count = j - i; 5773ffc7051SMatthew Dillon vm_object_pip_add(object, count); 5783ffc7051SMatthew Dillon swap_pager_putpages(object, marray + i, count, FALSE, rtvals + i); 5793ffc7051SMatthew Dillon vm_swapcache_write_count += count * PAGE_SIZE; 5803ffc7051SMatthew Dillon vm_swapcache_curburst -= count * PAGE_SIZE; 5813ffc7051SMatthew Dillon 5823ffc7051SMatthew Dillon while (i < j) { 5833ffc7051SMatthew Dillon if (rtvals[i] != VM_PAGER_PEND) { 584b12defdcSMatthew Dillon vm_page_busy_wait(marray[i], FALSE, "swppgfd"); 5853ffc7051SMatthew Dillon vm_page_io_finish(marray[i]); 586b12defdcSMatthew Dillon vm_page_wakeup(marray[i]); 587096e95c0SMatthew Dillon vm_object_pip_wakeup(object); 588096e95c0SMatthew Dillon } 5893ffc7051SMatthew Dillon ++i; 5903ffc7051SMatthew Dillon } 591b12defdcSMatthew Dillon vm_object_drop(object); 5923ffc7051SMatthew Dillon return(count); 593096e95c0SMatthew Dillon } 59400a3fdcaSMatthew Dillon 5953ffc7051SMatthew Dillon /* 5963ffc7051SMatthew Dillon * Test whether a VM page is suitable for writing to the swapcache. 5973ffc7051SMatthew Dillon * Does not test m->queue, PG_MARKER, or PG_SWAPPED. 5983ffc7051SMatthew Dillon * 5993ffc7051SMatthew Dillon * Returns 0 on success, 1 on failure 6003ffc7051SMatthew Dillon */ 6013ffc7051SMatthew Dillon static int 6023ffc7051SMatthew Dillon vm_swapcache_test(vm_page_t m) 6033ffc7051SMatthew Dillon { 6043ffc7051SMatthew Dillon vm_object_t object; 6053ffc7051SMatthew Dillon 606b12defdcSMatthew Dillon if (m->flags & PG_UNMANAGED) 6073ffc7051SMatthew Dillon return(1); 608b12defdcSMatthew Dillon if (m->hold_count || m->wire_count) 6093ffc7051SMatthew Dillon return(1); 6103ffc7051SMatthew Dillon if (m->valid != VM_PAGE_BITS_ALL) 6113ffc7051SMatthew Dillon return(1); 6123ffc7051SMatthew Dillon if (m->dirty & m->valid) 6133ffc7051SMatthew Dillon return(1); 6143ffc7051SMatthew Dillon if ((object = m->object) == NULL) 6153ffc7051SMatthew Dillon return(1); 6163ffc7051SMatthew Dillon if (object->type != OBJT_VNODE || 6173ffc7051SMatthew Dillon (object->flags & OBJ_DEAD)) { 6183ffc7051SMatthew Dillon return(1); 6193ffc7051SMatthew Dillon } 6203ffc7051SMatthew Dillon vm_page_test_dirty(m); 6213ffc7051SMatthew Dillon if (m->dirty & m->valid) 6223ffc7051SMatthew Dillon return(1); 6233ffc7051SMatthew Dillon return(0); 6243ffc7051SMatthew Dillon } 6253ffc7051SMatthew Dillon 6263ffc7051SMatthew Dillon /* 627f5f6d247SMatthew Dillon * Cleaning pass. 628f5f6d247SMatthew Dillon * 629f5f6d247SMatthew Dillon * We clean whole objects up to 16MB 6303ffc7051SMatthew Dillon */ 63100a3fdcaSMatthew Dillon static 63200a3fdcaSMatthew Dillon void 63300a3fdcaSMatthew Dillon vm_swapcache_cleaning(vm_object_t marker) 63400a3fdcaSMatthew Dillon { 63500a3fdcaSMatthew Dillon vm_object_t object; 63600a3fdcaSMatthew Dillon struct vnode *vp; 63700a3fdcaSMatthew Dillon int count; 638*0bf81261SMatthew Dillon int scount; 63900a3fdcaSMatthew Dillon int n; 64000a3fdcaSMatthew Dillon 64100a3fdcaSMatthew Dillon count = vm_swapcache_maxlaunder; 642*0bf81261SMatthew Dillon scount = vm_swapcache_maxscan; 64300a3fdcaSMatthew Dillon 64400a3fdcaSMatthew Dillon /* 64500a3fdcaSMatthew Dillon * Look for vnode objects 64600a3fdcaSMatthew Dillon */ 6472de4f77eSMatthew Dillon lwkt_gettoken(&vmobj_token); 6482de4f77eSMatthew Dillon 649f5f6d247SMatthew Dillon while ((object = TAILQ_NEXT(marker, object_list)) != NULL) { 6502f2d9e58SVenkatesh Srinivas /* 651f5f6d247SMatthew Dillon * We have to skip markers. We cannot hold/drop marker 652f5f6d247SMatthew Dillon * objects! 6532f2d9e58SVenkatesh Srinivas */ 654f5f6d247SMatthew Dillon if (object->type == OBJT_MARKER) { 655f5f6d247SMatthew Dillon vm_swapcache_movemarker(marker, object); 65600a3fdcaSMatthew Dillon continue; 6572f2d9e58SVenkatesh Srinivas } 65800a3fdcaSMatthew Dillon 65900a3fdcaSMatthew Dillon /* 660f5f6d247SMatthew Dillon * Safety, or in case there are millions of VM objects 661f5f6d247SMatthew Dillon * without swapcache backing. 66200a3fdcaSMatthew Dillon */ 663*0bf81261SMatthew Dillon if (--scount <= 0) 664f5f6d247SMatthew Dillon break; 66500a3fdcaSMatthew Dillon 66600a3fdcaSMatthew Dillon /* 667f5f6d247SMatthew Dillon * We must hold the object before potentially yielding. 66800a3fdcaSMatthew Dillon */ 669f5f6d247SMatthew Dillon vm_object_hold(object); 670f5f6d247SMatthew Dillon lwkt_yield(); 671f5f6d247SMatthew Dillon 672f5f6d247SMatthew Dillon /* 673f5f6d247SMatthew Dillon * Only operate on live VNODE objects that are either 674f5f6d247SMatthew Dillon * VREG or VCHR (VCHR for meta-data). 675f5f6d247SMatthew Dillon */ 676f5f6d247SMatthew Dillon if ((object->type != OBJT_VNODE) || 677f5f6d247SMatthew Dillon ((object->flags & OBJ_DEAD) || 678f5f6d247SMatthew Dillon object->swblock_count == 0) || 679f5f6d247SMatthew Dillon ((vp = object->handle) == NULL) || 680f5f6d247SMatthew Dillon (vp->v_type != VREG && vp->v_type != VCHR)) { 681f5f6d247SMatthew Dillon vm_object_drop(object); 682f5f6d247SMatthew Dillon /* object may be invalid now */ 683f5f6d247SMatthew Dillon vm_swapcache_movemarker(marker, object); 684f5f6d247SMatthew Dillon continue; 685f5f6d247SMatthew Dillon } 686f5f6d247SMatthew Dillon 687f5f6d247SMatthew Dillon /* 688f5f6d247SMatthew Dillon * Reset the object pindex stored in the marker if the 689f5f6d247SMatthew Dillon * working object has changed. 690f5f6d247SMatthew Dillon */ 691f5f6d247SMatthew Dillon if (marker->backing_object != object) { 692f5f6d247SMatthew Dillon marker->size = 0; 693f5f6d247SMatthew Dillon marker->backing_object_offset = 0; 694f5f6d247SMatthew Dillon marker->backing_object = object; 695f5f6d247SMatthew Dillon } 69600a3fdcaSMatthew Dillon 69700a3fdcaSMatthew Dillon /* 69800a3fdcaSMatthew Dillon * Look for swblocks starting at our iterator. 69900a3fdcaSMatthew Dillon * 70000a3fdcaSMatthew Dillon * The swap_pager_condfree() function attempts to free 70100a3fdcaSMatthew Dillon * swap space starting at the specified index. The index 70200a3fdcaSMatthew Dillon * will be updated on return. The function will return 70300a3fdcaSMatthew Dillon * a scan factor (NOT the number of blocks freed). 70400a3fdcaSMatthew Dillon * 70500a3fdcaSMatthew Dillon * If it must cut its scan of the object short due to an 70600a3fdcaSMatthew Dillon * excessive number of swblocks, or is able to free the 70700a3fdcaSMatthew Dillon * requested number of blocks, it will return n >= count 70800a3fdcaSMatthew Dillon * and we break and pick it back up on a future attempt. 709f5f6d247SMatthew Dillon * 710f5f6d247SMatthew Dillon * Scan the object linearly and try to batch large sets of 711f5f6d247SMatthew Dillon * blocks that are likely to clean out entire swap radix 712f5f6d247SMatthew Dillon * tree leafs. 71300a3fdcaSMatthew Dillon */ 714739be60bSMatthew Dillon lwkt_token_swap(); 71508fb7a9dSMatthew Dillon lwkt_reltoken(&vmobj_token); 71627b6ee03SMatthew Dillon 717f5f6d247SMatthew Dillon n = swap_pager_condfree(object, &marker->size, 718f5f6d247SMatthew Dillon (count + SWAP_META_MASK) & ~SWAP_META_MASK); 7192f2d9e58SVenkatesh Srinivas 720f5f6d247SMatthew Dillon vm_object_drop(object); /* object may be invalid now */ 72127b6ee03SMatthew Dillon lwkt_gettoken(&vmobj_token); 7222f2d9e58SVenkatesh Srinivas 72300a3fdcaSMatthew Dillon /* 724f5f6d247SMatthew Dillon * If we have exhausted the object or deleted our per-pass 725f5f6d247SMatthew Dillon * page limit then move us to the next object. Note that 726f5f6d247SMatthew Dillon * the current object may no longer be on the vm_object_list. 72700a3fdcaSMatthew Dillon */ 728f5f6d247SMatthew Dillon if (n <= 0 || 729f5f6d247SMatthew Dillon marker->backing_object_offset > vm_swapcache_cleanperobj) { 730f5f6d247SMatthew Dillon vm_swapcache_movemarker(marker, object); 73100a3fdcaSMatthew Dillon } 73200a3fdcaSMatthew Dillon 73300a3fdcaSMatthew Dillon /* 734f5f6d247SMatthew Dillon * If we have exhausted our max-launder stop for now. 73500a3fdcaSMatthew Dillon */ 736f5f6d247SMatthew Dillon count -= n; 737f5f6d247SMatthew Dillon marker->backing_object_offset += n * PAGE_SIZE; 738f5f6d247SMatthew Dillon if (count < 0) 739f5f6d247SMatthew Dillon break; 740f5f6d247SMatthew Dillon } 7417a175765SMatthew Dillon 7427a175765SMatthew Dillon /* 7437a175765SMatthew Dillon * If we wound up at the end of the list this will move the 7447a175765SMatthew Dillon * marker back to the beginning. 7457a175765SMatthew Dillon */ 7467a175765SMatthew Dillon if (object == NULL) 7477a175765SMatthew Dillon vm_swapcache_movemarker(marker, NULL); 7487a175765SMatthew Dillon 7492de4f77eSMatthew Dillon lwkt_reltoken(&vmobj_token); 75000a3fdcaSMatthew Dillon } 751f5f6d247SMatthew Dillon 752f5f6d247SMatthew Dillon /* 753f5f6d247SMatthew Dillon * Move the marker past the current object. Object can be stale, but we 754f5f6d247SMatthew Dillon * still need it to determine if the marker has to be moved. If the object 755f5f6d247SMatthew Dillon * is still the 'current object' (object after the marker), we hop-scotch 756f5f6d247SMatthew Dillon * the marker past it. 757f5f6d247SMatthew Dillon */ 758f5f6d247SMatthew Dillon static void 759f5f6d247SMatthew Dillon vm_swapcache_movemarker(vm_object_t marker, vm_object_t object) 760f5f6d247SMatthew Dillon { 761f5f6d247SMatthew Dillon if (TAILQ_NEXT(marker, object_list) == object) { 762f5f6d247SMatthew Dillon TAILQ_REMOVE(&vm_object_list, marker, object_list); 763f5f6d247SMatthew Dillon if (object) { 764f5f6d247SMatthew Dillon TAILQ_INSERT_AFTER(&vm_object_list, object, 765f5f6d247SMatthew Dillon marker, object_list); 766f5f6d247SMatthew Dillon } else { 767f5f6d247SMatthew Dillon TAILQ_INSERT_HEAD(&vm_object_list, 768f5f6d247SMatthew Dillon marker, object_list); 769f5f6d247SMatthew Dillon } 770f5f6d247SMatthew Dillon } 771f5f6d247SMatthew Dillon } 772