1 /* $NetBSD: rf_revent.c,v 1.18 2004/03/07 22:15:19 oster 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 1.18 2004/03/07 22:15:19 oster 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 void (*continueFunc)(void *), void *continueArg) 78 { 79 RF_Raid_t *raidPtr = reconDesc->raidPtr; 80 RF_ReconCtrl_t *rctrl = raidPtr->reconControl; 81 RF_ReconEvent_t *event; 82 83 RF_LOCK_MUTEX(rctrl->eq_mutex); 84 /* q null and count==0 must be equivalent conditions */ 85 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 86 87 rctrl->continueFunc = continueFunc; 88 rctrl->continueArg = continueArg; 89 90 91 /* mpsleep timeout value: secs = timo_val/hz. 'ticks' here is 92 defined as cycle-counter ticks, not softclock ticks */ 93 94 #define MAX_RECON_EXEC_USECS (100 * 1000) /* 100 ms */ 95 #define RECON_DELAY_MS 25 96 #define RECON_TIMO ((RECON_DELAY_MS * hz) / 1000) 97 98 /* we are not pre-emptible in the kernel, but we don't want to run 99 * forever. If we run w/o blocking for more than MAX_RECON_EXEC_TICKS 100 * ticks of the cycle counter, delay for RECON_DELAY before 101 * continuing. this may murder us with context switches, so we may 102 * need to increase both the MAX...TICKS and the RECON_DELAY_MS. */ 103 if (reconDesc->reconExecTimerRunning) { 104 int status; 105 106 RF_ETIMER_STOP(reconDesc->recon_exec_timer); 107 RF_ETIMER_EVAL(reconDesc->recon_exec_timer); 108 reconDesc->reconExecTicks += 109 RF_ETIMER_VAL_US(reconDesc->recon_exec_timer); 110 if (reconDesc->reconExecTicks > reconDesc->maxReconExecTicks) 111 reconDesc->maxReconExecTicks = 112 reconDesc->reconExecTicks; 113 if (reconDesc->reconExecTicks >= MAX_RECON_EXEC_USECS) { 114 /* we've been running too long. delay for 115 * RECON_DELAY_MS */ 116 #if RF_RECON_STATS > 0 117 reconDesc->numReconExecDelays++; 118 #endif /* RF_RECON_STATS > 0 */ 119 120 status = ltsleep(&reconDesc->reconExecTicks, PRIBIO, 121 "recon delay", RECON_TIMO, 122 &rctrl->eq_mutex); 123 RF_ASSERT(status == EWOULDBLOCK); 124 reconDesc->reconExecTicks = 0; 125 } 126 } 127 while (!rctrl->eventQueue) { 128 #if RF_RECON_STATS > 0 129 reconDesc->numReconEventWaits++; 130 #endif /* RF_RECON_STATS > 0 */ 131 132 ltsleep(&(rctrl)->eventQueue, PRIBIO, "raidframe eventq", 133 0, &((rctrl)->eq_mutex)); 134 135 reconDesc->reconExecTicks = 0; /* we've just waited */ 136 } 137 138 reconDesc->reconExecTimerRunning = 1; 139 if (RF_ETIMER_VAL_US(reconDesc->recon_exec_timer)!=0) { 140 /* it moved!! reset the timer. */ 141 RF_ETIMER_START(reconDesc->recon_exec_timer); 142 } 143 event = rctrl->eventQueue; 144 rctrl->eventQueue = event->next; 145 event->next = NULL; 146 rctrl->eq_count--; 147 148 /* q null and count==0 must be equivalent conditions */ 149 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 150 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 151 return (event); 152 } 153 /* enqueues a reconstruction event on the indicated queue */ 154 void 155 rf_CauseReconEvent(RF_Raid_t *raidPtr, RF_RowCol_t col, void *arg, 156 RF_Revent_t type) 157 { 158 RF_ReconCtrl_t *rctrl = raidPtr->reconControl; 159 RF_ReconEvent_t *event = GetReconEventDesc(col, arg, type); 160 161 if (type == RF_REVENT_BUFCLEAR) { 162 RF_ASSERT(col != rctrl->fcol); 163 } 164 RF_ASSERT(col >= 0 && col <= raidPtr->numCol); 165 RF_LOCK_MUTEX(rctrl->eq_mutex); 166 /* q null and count==0 must be equivalent conditions */ 167 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 168 event->next = rctrl->eventQueue; 169 rctrl->eventQueue = event; 170 rctrl->eq_count++; 171 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 172 173 wakeup(&(rctrl)->eventQueue); 174 } 175 /* allocates and initializes a recon event descriptor */ 176 static RF_ReconEvent_t * 177 GetReconEventDesc(RF_RowCol_t col, void *arg, RF_Revent_t type) 178 { 179 RF_ReconEvent_t *t; 180 181 t = pool_get(&rf_pools.revent, PR_WAITOK); 182 t->col = col; 183 t->arg = arg; 184 t->type = type; 185 t->next = NULL; 186 return (t); 187 } 188 189 void 190 rf_FreeReconEventDesc(RF_ReconEvent_t *event) 191 { 192 pool_put(&rf_pools.revent, event); 193 } 194