1 /* $NetBSD: rf_revent.c,v 1.5 1999/08/13 03:26:55 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 51 extern int hz; 52 53 #define DO_WAIT(_rc) 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 RF_ReconEvent_t * 64 rf_GetNextReconEvent(RF_RaidReconDesc_t *, 65 RF_RowCol_t, void (*continueFunc) (void *), 66 void *); 67 68 static void rf_ShutdownReconEvent(ignored) 69 void *ignored; 70 { 71 RF_FREELIST_DESTROY(rf_revent_freelist, next, (RF_ReconEvent_t *)); 72 } 73 74 int 75 rf_ConfigureReconEvent(listp) 76 RF_ShutdownList_t **listp; 77 { 78 int rc; 79 80 RF_FREELIST_CREATE(rf_revent_freelist, RF_MAX_FREE_REVENT, 81 RF_REVENT_INC, sizeof(RF_ReconEvent_t)); 82 if (rf_revent_freelist == NULL) 83 return (ENOMEM); 84 rc = rf_ShutdownCreate(listp, rf_ShutdownReconEvent, NULL); 85 if (rc) { 86 RF_ERRORMSG3("Unable to add to shutdown list file %s line %d rc=%d\n", __FILE__, 87 __LINE__, rc); 88 rf_ShutdownReconEvent(NULL); 89 return (rc); 90 } 91 RF_FREELIST_PRIME(rf_revent_freelist, RF_REVENT_INITIAL, next, 92 (RF_ReconEvent_t *)); 93 return (0); 94 } 95 /* returns the next reconstruction event, blocking the calling thread until 96 * one becomes available 97 */ 98 99 /* will now return null if it is blocked or will return an event if it is not */ 100 101 RF_ReconEvent_t * 102 rf_GetNextReconEvent(reconDesc, row, continueFunc, continueArg) 103 RF_RaidReconDesc_t *reconDesc; 104 RF_RowCol_t row; 105 void (*continueFunc) (void *); 106 void *continueArg; 107 { 108 RF_Raid_t *raidPtr = reconDesc->raidPtr; 109 RF_ReconCtrl_t *rctrl = raidPtr->reconControl[row]; 110 RF_ReconEvent_t *event; 111 112 RF_ASSERT(row >= 0 && row <= raidPtr->numRow); 113 RF_LOCK_MUTEX(rctrl->eq_mutex); 114 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); /* q null and count==0 115 * must be equivalent 116 * conditions */ 117 118 119 rctrl->continueFunc = continueFunc; 120 rctrl->continueArg = continueArg; 121 122 123 /* mpsleep timeout value: secs = timo_val/hz. 'ticks' here is defined as cycle-counter ticks, not softclock ticks */ 124 #define MAX_RECON_EXEC_USECS (100 * 1000) /* 100 ms */ 125 #define RECON_DELAY_MS 25 126 #define RECON_TIMO ((RECON_DELAY_MS * hz) / 1000) 127 128 /* we are not pre-emptible in the kernel, but we don't want to run 129 * forever. If we run w/o blocking for more than MAX_RECON_EXEC_TICKS 130 * ticks of the cycle counter, delay for RECON_DELAY before 131 * continuing. this may murder us with context switches, so we may 132 * need to increase both the MAX...TICKS and the RECON_DELAY_MS. */ 133 if (reconDesc->reconExecTimerRunning) { 134 int status; 135 136 RF_ETIMER_STOP(reconDesc->recon_exec_timer); 137 RF_ETIMER_EVAL(reconDesc->recon_exec_timer); 138 reconDesc->reconExecTicks += RF_ETIMER_VAL_US(reconDesc->recon_exec_timer); 139 if (reconDesc->reconExecTicks > reconDesc->maxReconExecTicks) 140 reconDesc->maxReconExecTicks = reconDesc->reconExecTicks; 141 if (reconDesc->reconExecTicks >= MAX_RECON_EXEC_USECS) { 142 /* we've been running too long. delay for 143 * RECON_DELAY_MS */ 144 #if RF_RECON_STATS > 0 145 reconDesc->numReconExecDelays++; 146 #endif /* RF_RECON_STATS > 0 */ 147 status = tsleep(&reconDesc->reconExecTicks, PRIBIO, "recon delay", RECON_TIMO); 148 RF_ASSERT(status == EWOULDBLOCK); 149 reconDesc->reconExecTicks = 0; 150 } 151 } 152 while (!rctrl->eventQueue) { 153 #if RF_RECON_STATS > 0 154 reconDesc->numReconEventWaits++; 155 #endif /* RF_RECON_STATS > 0 */ 156 DO_WAIT(rctrl); 157 reconDesc->reconExecTicks = 0; /* we've just waited */ 158 } 159 160 reconDesc->reconExecTimerRunning = 1; 161 RF_ETIMER_START(reconDesc->recon_exec_timer); 162 163 event = rctrl->eventQueue; 164 rctrl->eventQueue = event->next; 165 event->next = NULL; 166 rctrl->eq_count--; 167 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); /* q null and count==0 168 * must be equivalent 169 * conditions */ 170 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 171 return (event); 172 } 173 /* enqueues a reconstruction event on the indicated queue */ 174 void 175 rf_CauseReconEvent(raidPtr, row, col, arg, type) 176 RF_Raid_t *raidPtr; 177 RF_RowCol_t row; 178 RF_RowCol_t col; 179 void *arg; 180 RF_Revent_t type; 181 { 182 RF_ReconCtrl_t *rctrl = raidPtr->reconControl[row]; 183 RF_ReconEvent_t *event = GetReconEventDesc(row, col, arg, type); 184 185 if (type == RF_REVENT_BUFCLEAR) { 186 RF_ASSERT(col != rctrl->fcol); 187 } 188 RF_ASSERT(row >= 0 && row <= raidPtr->numRow && col >= 0 && col <= raidPtr->numCol); 189 RF_LOCK_MUTEX(rctrl->eq_mutex); 190 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); /* q null and count==0 191 * must be equivalent 192 * conditions */ 193 event->next = rctrl->eventQueue; 194 rctrl->eventQueue = event; 195 rctrl->eq_count++; 196 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 197 198 DO_SIGNAL(rctrl); 199 } 200 /* allocates and initializes a recon event descriptor */ 201 static RF_ReconEvent_t * 202 GetReconEventDesc(row, col, arg, type) 203 RF_RowCol_t row; 204 RF_RowCol_t col; 205 void *arg; 206 RF_Revent_t type; 207 { 208 RF_ReconEvent_t *t; 209 210 RF_FREELIST_GET(rf_revent_freelist, t, next, (RF_ReconEvent_t *)); 211 if (t == NULL) 212 return (NULL); 213 t->col = col; 214 t->arg = arg; 215 t->type = type; 216 return (t); 217 } 218 219 void 220 rf_FreeReconEventDesc(event) 221 RF_ReconEvent_t *event; 222 { 223 RF_FREELIST_FREE(rf_revent_freelist, event, next); 224 } 225