1 /* $NetBSD: rf_revent.c,v 1.9 2000/09/21 01:45:46 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/errno.h> 33 34 #include "rf_raid.h" 35 #include "rf_revent.h" 36 #include "rf_etimer.h" 37 #include "rf_general.h" 38 #include "rf_freelist.h" 39 #include "rf_desc.h" 40 #include "rf_shutdown.h" 41 42 static RF_FreeList_t *rf_revent_freelist; 43 #define RF_MAX_FREE_REVENT 128 44 #define RF_REVENT_INC 8 45 #define RF_REVENT_INITIAL 8 46 47 48 49 #include <sys/proc.h> 50 #include <sys/kernel.h> 51 52 #define DO_WAIT(_rc) \ 53 ltsleep(&(_rc)->eventQueue, PRIBIO, "raidframe eventq", \ 54 0, &((_rc)->eq_mutex)) 55 56 #define DO_SIGNAL(_rc) wakeup(&(_rc)->eventQueue) 57 58 59 static void rf_ShutdownReconEvent(void *); 60 61 static RF_ReconEvent_t * 62 GetReconEventDesc(RF_RowCol_t row, RF_RowCol_t col, 63 void *arg, RF_Revent_t type); 64 65 static void rf_ShutdownReconEvent(ignored) 66 void *ignored; 67 { 68 RF_FREELIST_DESTROY(rf_revent_freelist, next, (RF_ReconEvent_t *)); 69 } 70 71 int 72 rf_ConfigureReconEvent(listp) 73 RF_ShutdownList_t **listp; 74 { 75 int rc; 76 77 RF_FREELIST_CREATE(rf_revent_freelist, RF_MAX_FREE_REVENT, 78 RF_REVENT_INC, sizeof(RF_ReconEvent_t)); 79 if (rf_revent_freelist == NULL) 80 return (ENOMEM); 81 rc = rf_ShutdownCreate(listp, rf_ShutdownReconEvent, NULL); 82 if (rc) { 83 RF_ERRORMSG3("Unable to add to shutdown list file %s line %d rc=%d\n", __FILE__, 84 __LINE__, rc); 85 rf_ShutdownReconEvent(NULL); 86 return (rc); 87 } 88 RF_FREELIST_PRIME(rf_revent_freelist, RF_REVENT_INITIAL, next, 89 (RF_ReconEvent_t *)); 90 return (0); 91 } 92 93 /* returns the next reconstruction event, blocking the calling thread 94 * until one becomes available. will now return null if it is blocked 95 * or will return an event if it is not */ 96 97 RF_ReconEvent_t * 98 rf_GetNextReconEvent(reconDesc, row, continueFunc, continueArg) 99 RF_RaidReconDesc_t *reconDesc; 100 RF_RowCol_t row; 101 void (*continueFunc) (void *); 102 void *continueArg; 103 { 104 RF_Raid_t *raidPtr = reconDesc->raidPtr; 105 RF_ReconCtrl_t *rctrl = raidPtr->reconControl[row]; 106 RF_ReconEvent_t *event; 107 108 RF_ASSERT(row >= 0 && row <= raidPtr->numRow); 109 RF_LOCK_MUTEX(rctrl->eq_mutex); 110 /* q null and count==0 must be equivalent conditions */ 111 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 112 113 rctrl->continueFunc = continueFunc; 114 rctrl->continueArg = continueArg; 115 116 117 /* mpsleep timeout value: secs = timo_val/hz. 'ticks' here is 118 defined as cycle-counter ticks, not softclock ticks */ 119 120 #define MAX_RECON_EXEC_USECS (100 * 1000) /* 100 ms */ 121 #define RECON_DELAY_MS 25 122 #define RECON_TIMO ((RECON_DELAY_MS * hz) / 1000) 123 124 /* we are not pre-emptible in the kernel, but we don't want to run 125 * forever. If we run w/o blocking for more than MAX_RECON_EXEC_TICKS 126 * ticks of the cycle counter, delay for RECON_DELAY before 127 * continuing. this may murder us with context switches, so we may 128 * need to increase both the MAX...TICKS and the RECON_DELAY_MS. */ 129 if (reconDesc->reconExecTimerRunning) { 130 int status; 131 132 RF_ETIMER_STOP(reconDesc->recon_exec_timer); 133 RF_ETIMER_EVAL(reconDesc->recon_exec_timer); 134 reconDesc->reconExecTicks += 135 RF_ETIMER_VAL_US(reconDesc->recon_exec_timer); 136 if (reconDesc->reconExecTicks > reconDesc->maxReconExecTicks) 137 reconDesc->maxReconExecTicks = 138 reconDesc->reconExecTicks; 139 if (reconDesc->reconExecTicks >= MAX_RECON_EXEC_USECS) { 140 /* we've been running too long. delay for 141 * RECON_DELAY_MS */ 142 #if RF_RECON_STATS > 0 143 reconDesc->numReconExecDelays++; 144 #endif /* RF_RECON_STATS > 0 */ 145 146 status = ltsleep(&reconDesc->reconExecTicks, PRIBIO, 147 "recon delay", RECON_TIMO, 148 &rctrl->eq_mutex); 149 RF_ASSERT(status == EWOULDBLOCK); 150 reconDesc->reconExecTicks = 0; 151 } 152 } 153 while (!rctrl->eventQueue) { 154 #if RF_RECON_STATS > 0 155 reconDesc->numReconEventWaits++; 156 #endif /* RF_RECON_STATS > 0 */ 157 DO_WAIT(rctrl); 158 reconDesc->reconExecTicks = 0; /* we've just waited */ 159 } 160 161 reconDesc->reconExecTimerRunning = 1; 162 if (RF_ETIMER_VAL_US(reconDesc->recon_exec_timer)!=0) { 163 /* it moved!! reset the timer. */ 164 RF_ETIMER_START(reconDesc->recon_exec_timer); 165 } 166 event = rctrl->eventQueue; 167 rctrl->eventQueue = event->next; 168 event->next = NULL; 169 rctrl->eq_count--; 170 171 /* q null and count==0 must be equivalent conditions */ 172 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 173 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 174 return (event); 175 } 176 /* enqueues a reconstruction event on the indicated queue */ 177 void 178 rf_CauseReconEvent(raidPtr, row, col, arg, type) 179 RF_Raid_t *raidPtr; 180 RF_RowCol_t row; 181 RF_RowCol_t col; 182 void *arg; 183 RF_Revent_t type; 184 { 185 RF_ReconCtrl_t *rctrl = raidPtr->reconControl[row]; 186 RF_ReconEvent_t *event = GetReconEventDesc(row, col, arg, type); 187 188 if (type == RF_REVENT_BUFCLEAR) { 189 RF_ASSERT(col != rctrl->fcol); 190 } 191 RF_ASSERT(row >= 0 && row <= raidPtr->numRow && col >= 0 && col <= raidPtr->numCol); 192 RF_LOCK_MUTEX(rctrl->eq_mutex); 193 /* q null and count==0 must be equivalent conditions */ 194 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 195 event->next = rctrl->eventQueue; 196 rctrl->eventQueue = event; 197 rctrl->eq_count++; 198 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 199 200 DO_SIGNAL(rctrl); 201 } 202 /* allocates and initializes a recon event descriptor */ 203 static RF_ReconEvent_t * 204 GetReconEventDesc(row, col, arg, type) 205 RF_RowCol_t row; 206 RF_RowCol_t col; 207 void *arg; 208 RF_Revent_t type; 209 { 210 RF_ReconEvent_t *t; 211 212 RF_FREELIST_GET(rf_revent_freelist, t, next, (RF_ReconEvent_t *)); 213 if (t == NULL) 214 return (NULL); 215 t->col = col; 216 t->arg = arg; 217 t->type = type; 218 return (t); 219 } 220 221 void 222 rf_FreeReconEventDesc(event) 223 RF_ReconEvent_t *event; 224 { 225 RF_FREELIST_FREE(rf_revent_freelist, event, next); 226 } 227