1 /* $NetBSD: rf_revent.c,v 1.7 2000/05/30 02:04:29 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 tsleep(&(_rc)->eventQueue, PRIBIO, "raidframe eventq", 0) 54 55 #define DO_SIGNAL(_rc) wakeup(&(_rc)->eventQueue) 56 57 58 static void rf_ShutdownReconEvent(void *); 59 60 static RF_ReconEvent_t * 61 GetReconEventDesc(RF_RowCol_t row, RF_RowCol_t col, 62 void *arg, RF_Revent_t type); 63 64 static void rf_ShutdownReconEvent(ignored) 65 void *ignored; 66 { 67 RF_FREELIST_DESTROY(rf_revent_freelist, next, (RF_ReconEvent_t *)); 68 } 69 70 int 71 rf_ConfigureReconEvent(listp) 72 RF_ShutdownList_t **listp; 73 { 74 int rc; 75 76 RF_FREELIST_CREATE(rf_revent_freelist, RF_MAX_FREE_REVENT, 77 RF_REVENT_INC, sizeof(RF_ReconEvent_t)); 78 if (rf_revent_freelist == NULL) 79 return (ENOMEM); 80 rc = rf_ShutdownCreate(listp, rf_ShutdownReconEvent, NULL); 81 if (rc) { 82 RF_ERRORMSG3("Unable to add to shutdown list file %s line %d rc=%d\n", __FILE__, 83 __LINE__, rc); 84 rf_ShutdownReconEvent(NULL); 85 return (rc); 86 } 87 RF_FREELIST_PRIME(rf_revent_freelist, RF_REVENT_INITIAL, next, 88 (RF_ReconEvent_t *)); 89 return (0); 90 } 91 92 /* returns the next reconstruction event, blocking the calling thread 93 * until one becomes available. will now return null if it is blocked 94 * or will return an event if it is not */ 95 96 RF_ReconEvent_t * 97 rf_GetNextReconEvent(reconDesc, row, continueFunc, continueArg) 98 RF_RaidReconDesc_t *reconDesc; 99 RF_RowCol_t row; 100 void (*continueFunc) (void *); 101 void *continueArg; 102 { 103 RF_Raid_t *raidPtr = reconDesc->raidPtr; 104 RF_ReconCtrl_t *rctrl = raidPtr->reconControl[row]; 105 RF_ReconEvent_t *event; 106 107 RF_ASSERT(row >= 0 && row <= raidPtr->numRow); 108 RF_LOCK_MUTEX(rctrl->eq_mutex); 109 /* q null and count==0 must be equivalent conditions */ 110 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 111 112 rctrl->continueFunc = continueFunc; 113 rctrl->continueArg = continueArg; 114 115 116 /* mpsleep timeout value: secs = timo_val/hz. 'ticks' here is 117 defined as cycle-counter ticks, not softclock ticks */ 118 119 #define MAX_RECON_EXEC_USECS (100 * 1000) /* 100 ms */ 120 #define RECON_DELAY_MS 25 121 #define RECON_TIMO ((RECON_DELAY_MS * hz) / 1000) 122 123 /* we are not pre-emptible in the kernel, but we don't want to run 124 * forever. If we run w/o blocking for more than MAX_RECON_EXEC_TICKS 125 * ticks of the cycle counter, delay for RECON_DELAY before 126 * continuing. this may murder us with context switches, so we may 127 * need to increase both the MAX...TICKS and the RECON_DELAY_MS. */ 128 if (reconDesc->reconExecTimerRunning) { 129 int status; 130 131 RF_ETIMER_STOP(reconDesc->recon_exec_timer); 132 RF_ETIMER_EVAL(reconDesc->recon_exec_timer); 133 reconDesc->reconExecTicks += 134 RF_ETIMER_VAL_US(reconDesc->recon_exec_timer); 135 if (reconDesc->reconExecTicks > reconDesc->maxReconExecTicks) 136 reconDesc->maxReconExecTicks = 137 reconDesc->reconExecTicks; 138 if (reconDesc->reconExecTicks >= MAX_RECON_EXEC_USECS) { 139 /* we've been running too long. delay for 140 * RECON_DELAY_MS */ 141 #if RF_RECON_STATS > 0 142 reconDesc->numReconExecDelays++; 143 #endif /* RF_RECON_STATS > 0 */ 144 status = tsleep(&reconDesc->reconExecTicks, 145 PRIBIO, "recon delay", RECON_TIMO); 146 RF_ASSERT(status == EWOULDBLOCK); 147 reconDesc->reconExecTicks = 0; 148 } 149 } 150 while (!rctrl->eventQueue) { 151 #if RF_RECON_STATS > 0 152 reconDesc->numReconEventWaits++; 153 #endif /* RF_RECON_STATS > 0 */ 154 DO_WAIT(rctrl); 155 reconDesc->reconExecTicks = 0; /* we've just waited */ 156 } 157 158 reconDesc->reconExecTimerRunning = 1; 159 RF_ETIMER_START(reconDesc->recon_exec_timer); 160 161 event = rctrl->eventQueue; 162 rctrl->eventQueue = event->next; 163 event->next = NULL; 164 rctrl->eq_count--; 165 166 /* q null and count==0 must be equivalent conditions */ 167 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 168 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 169 return (event); 170 } 171 /* enqueues a reconstruction event on the indicated queue */ 172 void 173 rf_CauseReconEvent(raidPtr, row, col, arg, type) 174 RF_Raid_t *raidPtr; 175 RF_RowCol_t row; 176 RF_RowCol_t col; 177 void *arg; 178 RF_Revent_t type; 179 { 180 RF_ReconCtrl_t *rctrl = raidPtr->reconControl[row]; 181 RF_ReconEvent_t *event = GetReconEventDesc(row, col, arg, type); 182 183 if (type == RF_REVENT_BUFCLEAR) { 184 RF_ASSERT(col != rctrl->fcol); 185 } 186 RF_ASSERT(row >= 0 && row <= raidPtr->numRow && col >= 0 && col <= raidPtr->numCol); 187 RF_LOCK_MUTEX(rctrl->eq_mutex); 188 /* q null and count==0 must be equivalent conditions */ 189 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 190 event->next = rctrl->eventQueue; 191 rctrl->eventQueue = event; 192 rctrl->eq_count++; 193 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 194 195 DO_SIGNAL(rctrl); 196 } 197 /* allocates and initializes a recon event descriptor */ 198 static RF_ReconEvent_t * 199 GetReconEventDesc(row, col, arg, type) 200 RF_RowCol_t row; 201 RF_RowCol_t col; 202 void *arg; 203 RF_Revent_t type; 204 { 205 RF_ReconEvent_t *t; 206 207 RF_FREELIST_GET(rf_revent_freelist, t, next, (RF_ReconEvent_t *)); 208 if (t == NULL) 209 return (NULL); 210 t->col = col; 211 t->arg = arg; 212 t->type = type; 213 return (t); 214 } 215 216 void 217 rf_FreeReconEventDesc(event) 218 RF_ReconEvent_t *event; 219 { 220 RF_FREELIST_FREE(rf_revent_freelist, event, next); 221 } 222