1 /* $NetBSD: rf_revent.c,v 1.22 2005/12/11 12:23:37 christos Exp $ */ 2 /* 3 * Copyright (c) 1995 Carnegie-Mellon University. 4 * All rights reserved. 5 * 6 * Author: 7 * 8 * Permission to use, copy, modify and distribute this software and 9 * its documentation is hereby granted, provided that both the copyright 10 * notice and this permission notice appear in all copies of the 11 * software, derivative works or modified versions, and any portions 12 * thereof, and that both notices appear in supporting documentation. 13 * 14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 16 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 17 * 18 * Carnegie Mellon requests users of this software to return to 19 * 20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 21 * School of Computer Science 22 * Carnegie Mellon University 23 * Pittsburgh PA 15213-3890 24 * 25 * any improvements or extensions that they make and grant Carnegie the 26 * rights to redistribute these changes. 27 */ 28 /* 29 * revent.c -- reconstruction event handling code 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: rf_revent.c,v 1.22 2005/12/11 12:23:37 christos Exp $"); 34 35 #include <sys/errno.h> 36 37 #include "rf_raid.h" 38 #include "rf_revent.h" 39 #include "rf_etimer.h" 40 #include "rf_general.h" 41 #include "rf_desc.h" 42 #include "rf_shutdown.h" 43 44 #define RF_MAX_FREE_REVENT 128 45 #define RF_MIN_FREE_REVENT 32 46 47 #include <sys/proc.h> 48 #include <sys/kernel.h> 49 50 static void rf_ShutdownReconEvent(void *); 51 52 static RF_ReconEvent_t * 53 GetReconEventDesc(RF_RowCol_t col, void *arg, RF_Revent_t type); 54 55 static void rf_ShutdownReconEvent(void *ignored) 56 { 57 pool_destroy(&rf_pools.revent); 58 } 59 60 int 61 rf_ConfigureReconEvent(RF_ShutdownList_t **listp) 62 { 63 64 rf_pool_init(&rf_pools.revent, sizeof(RF_ReconEvent_t), 65 "rf_revent_pl", RF_MIN_FREE_REVENT, RF_MAX_FREE_REVENT); 66 rf_ShutdownCreate(listp, rf_ShutdownReconEvent, NULL); 67 68 return (0); 69 } 70 71 /* returns the next reconstruction event, blocking the calling thread 72 * until one becomes available. will now return null if it is blocked 73 * or will return an event if it is not */ 74 75 RF_ReconEvent_t * 76 rf_GetNextReconEvent(RF_RaidReconDesc_t *reconDesc) 77 { 78 RF_Raid_t *raidPtr = reconDesc->raidPtr; 79 RF_ReconCtrl_t *rctrl = raidPtr->reconControl; 80 RF_ReconEvent_t *event; 81 82 RF_LOCK_MUTEX(rctrl->eq_mutex); 83 /* q null and count==0 must be equivalent conditions */ 84 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 85 86 /* mpsleep timeout value: secs = timo_val/hz. 'ticks' here is 87 defined as cycle-counter ticks, not softclock ticks */ 88 89 #define MAX_RECON_EXEC_USECS (100 * 1000) /* 100 ms */ 90 #define RECON_DELAY_MS 25 91 #define RECON_TIMO ((RECON_DELAY_MS * hz) / 1000) 92 93 /* we are not pre-emptible in the kernel, but we don't want to run 94 * forever. If we run w/o blocking for more than MAX_RECON_EXEC_TICKS 95 * ticks of the cycle counter, delay for RECON_DELAY before 96 * continuing. this may murder us with context switches, so we may 97 * need to increase both the MAX...TICKS and the RECON_DELAY_MS. */ 98 if (reconDesc->reconExecTimerRunning) { 99 int status; 100 101 RF_ETIMER_STOP(reconDesc->recon_exec_timer); 102 RF_ETIMER_EVAL(reconDesc->recon_exec_timer); 103 reconDesc->reconExecTicks += 104 RF_ETIMER_VAL_US(reconDesc->recon_exec_timer); 105 if (reconDesc->reconExecTicks > reconDesc->maxReconExecTicks) 106 reconDesc->maxReconExecTicks = 107 reconDesc->reconExecTicks; 108 if (reconDesc->reconExecTicks >= MAX_RECON_EXEC_USECS) { 109 /* we've been running too long. delay for 110 * RECON_DELAY_MS */ 111 #if RF_RECON_STATS > 0 112 reconDesc->numReconExecDelays++; 113 #endif /* RF_RECON_STATS > 0 */ 114 115 status = ltsleep(&reconDesc->reconExecTicks, PRIBIO, 116 "recon delay", RECON_TIMO, 117 &rctrl->eq_mutex); 118 RF_ASSERT(status == EWOULDBLOCK); 119 reconDesc->reconExecTicks = 0; 120 } 121 } 122 while (!rctrl->eventQueue) { 123 #if RF_RECON_STATS > 0 124 reconDesc->numReconEventWaits++; 125 #endif /* RF_RECON_STATS > 0 */ 126 127 ltsleep(&(rctrl)->eventQueue, PRIBIO, "raidframe eventq", 128 0, &((rctrl)->eq_mutex)); 129 130 reconDesc->reconExecTicks = 0; /* we've just waited */ 131 } 132 133 reconDesc->reconExecTimerRunning = 1; 134 if (RF_ETIMER_VAL_US(reconDesc->recon_exec_timer)!=0) { 135 /* it moved!! reset the timer. */ 136 RF_ETIMER_START(reconDesc->recon_exec_timer); 137 } 138 event = rctrl->eventQueue; 139 rctrl->eventQueue = event->next; 140 event->next = NULL; 141 rctrl->eq_count--; 142 143 /* q null and count==0 must be equivalent conditions */ 144 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 145 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 146 return (event); 147 } 148 /* enqueues a reconstruction event on the indicated queue */ 149 void 150 rf_CauseReconEvent(RF_Raid_t *raidPtr, RF_RowCol_t col, void *arg, 151 RF_Revent_t type) 152 { 153 RF_ReconCtrl_t *rctrl = raidPtr->reconControl; 154 RF_ReconEvent_t *event = GetReconEventDesc(col, arg, type); 155 156 if (type == RF_REVENT_BUFCLEAR) { 157 RF_ASSERT(col != rctrl->fcol); 158 } 159 RF_ASSERT(col >= 0 && col <= raidPtr->numCol); 160 RF_LOCK_MUTEX(rctrl->eq_mutex); 161 /* q null and count==0 must be equivalent conditions */ 162 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 163 event->next = rctrl->eventQueue; 164 rctrl->eventQueue = event; 165 rctrl->eq_count++; 166 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 167 168 wakeup(&(rctrl)->eventQueue); 169 } 170 /* allocates and initializes a recon event descriptor */ 171 static RF_ReconEvent_t * 172 GetReconEventDesc(RF_RowCol_t col, void *arg, RF_Revent_t type) 173 { 174 RF_ReconEvent_t *t; 175 176 t = pool_get(&rf_pools.revent, PR_WAITOK); 177 t->col = col; 178 t->arg = arg; 179 t->type = type; 180 t->next = NULL; 181 return (t); 182 } 183 184 /* 185 rf_DrainReconEventQueue() -- used in the event of a reconstruction 186 problem, this function simply drains all pending events from the 187 reconstruct event queue. 188 */ 189 190 void 191 rf_DrainReconEventQueue(RF_RaidReconDesc_t *reconDesc) 192 { 193 RF_ReconCtrl_t *rctrl = reconDesc->raidPtr->reconControl; 194 RF_ReconEvent_t *event; 195 196 RF_LOCK_MUTEX(rctrl->eq_mutex); 197 while (rctrl->eventQueue!=NULL) { 198 199 event = rctrl->eventQueue; 200 rctrl->eventQueue = event->next; 201 event->next = NULL; 202 rctrl->eq_count--; 203 /* dump it */ 204 rf_FreeReconEventDesc(event); 205 } 206 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 207 } 208 209 void 210 rf_FreeReconEventDesc(RF_ReconEvent_t *event) 211 { 212 pool_put(&rf_pools.revent, event); 213 } 214