1 /* $NetBSD: rf_revent.c,v 1.10 2001/11/13 07:11:16 lukem 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 1.10 2001/11/13 07:11:16 lukem 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_freelist.h" 42 #include "rf_desc.h" 43 #include "rf_shutdown.h" 44 45 static RF_FreeList_t *rf_revent_freelist; 46 #define RF_MAX_FREE_REVENT 128 47 #define RF_REVENT_INC 8 48 #define RF_REVENT_INITIAL 8 49 50 51 52 #include <sys/proc.h> 53 #include <sys/kernel.h> 54 55 #define DO_WAIT(_rc) \ 56 ltsleep(&(_rc)->eventQueue, PRIBIO, "raidframe eventq", \ 57 0, &((_rc)->eq_mutex)) 58 59 #define DO_SIGNAL(_rc) wakeup(&(_rc)->eventQueue) 60 61 62 static void rf_ShutdownReconEvent(void *); 63 64 static RF_ReconEvent_t * 65 GetReconEventDesc(RF_RowCol_t row, RF_RowCol_t col, 66 void *arg, RF_Revent_t type); 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 96 /* returns the next reconstruction event, blocking the calling thread 97 * until one becomes available. will now return null if it is blocked 98 * or will return an event if it is not */ 99 100 RF_ReconEvent_t * 101 rf_GetNextReconEvent(reconDesc, row, continueFunc, continueArg) 102 RF_RaidReconDesc_t *reconDesc; 103 RF_RowCol_t row; 104 void (*continueFunc) (void *); 105 void *continueArg; 106 { 107 RF_Raid_t *raidPtr = reconDesc->raidPtr; 108 RF_ReconCtrl_t *rctrl = raidPtr->reconControl[row]; 109 RF_ReconEvent_t *event; 110 111 RF_ASSERT(row >= 0 && row <= raidPtr->numRow); 112 RF_LOCK_MUTEX(rctrl->eq_mutex); 113 /* q null and count==0 must be equivalent conditions */ 114 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 115 116 rctrl->continueFunc = continueFunc; 117 rctrl->continueArg = continueArg; 118 119 120 /* mpsleep timeout value: secs = timo_val/hz. 'ticks' here is 121 defined as cycle-counter ticks, not softclock ticks */ 122 123 #define MAX_RECON_EXEC_USECS (100 * 1000) /* 100 ms */ 124 #define RECON_DELAY_MS 25 125 #define RECON_TIMO ((RECON_DELAY_MS * hz) / 1000) 126 127 /* we are not pre-emptible in the kernel, but we don't want to run 128 * forever. If we run w/o blocking for more than MAX_RECON_EXEC_TICKS 129 * ticks of the cycle counter, delay for RECON_DELAY before 130 * continuing. this may murder us with context switches, so we may 131 * need to increase both the MAX...TICKS and the RECON_DELAY_MS. */ 132 if (reconDesc->reconExecTimerRunning) { 133 int status; 134 135 RF_ETIMER_STOP(reconDesc->recon_exec_timer); 136 RF_ETIMER_EVAL(reconDesc->recon_exec_timer); 137 reconDesc->reconExecTicks += 138 RF_ETIMER_VAL_US(reconDesc->recon_exec_timer); 139 if (reconDesc->reconExecTicks > reconDesc->maxReconExecTicks) 140 reconDesc->maxReconExecTicks = 141 reconDesc->reconExecTicks; 142 if (reconDesc->reconExecTicks >= MAX_RECON_EXEC_USECS) { 143 /* we've been running too long. delay for 144 * RECON_DELAY_MS */ 145 #if RF_RECON_STATS > 0 146 reconDesc->numReconExecDelays++; 147 #endif /* RF_RECON_STATS > 0 */ 148 149 status = ltsleep(&reconDesc->reconExecTicks, PRIBIO, 150 "recon delay", RECON_TIMO, 151 &rctrl->eq_mutex); 152 RF_ASSERT(status == EWOULDBLOCK); 153 reconDesc->reconExecTicks = 0; 154 } 155 } 156 while (!rctrl->eventQueue) { 157 #if RF_RECON_STATS > 0 158 reconDesc->numReconEventWaits++; 159 #endif /* RF_RECON_STATS > 0 */ 160 DO_WAIT(rctrl); 161 reconDesc->reconExecTicks = 0; /* we've just waited */ 162 } 163 164 reconDesc->reconExecTimerRunning = 1; 165 if (RF_ETIMER_VAL_US(reconDesc->recon_exec_timer)!=0) { 166 /* it moved!! reset the timer. */ 167 RF_ETIMER_START(reconDesc->recon_exec_timer); 168 } 169 event = rctrl->eventQueue; 170 rctrl->eventQueue = event->next; 171 event->next = NULL; 172 rctrl->eq_count--; 173 174 /* q null and count==0 must be equivalent conditions */ 175 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 176 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 177 return (event); 178 } 179 /* enqueues a reconstruction event on the indicated queue */ 180 void 181 rf_CauseReconEvent(raidPtr, row, col, arg, type) 182 RF_Raid_t *raidPtr; 183 RF_RowCol_t row; 184 RF_RowCol_t col; 185 void *arg; 186 RF_Revent_t type; 187 { 188 RF_ReconCtrl_t *rctrl = raidPtr->reconControl[row]; 189 RF_ReconEvent_t *event = GetReconEventDesc(row, col, arg, type); 190 191 if (type == RF_REVENT_BUFCLEAR) { 192 RF_ASSERT(col != rctrl->fcol); 193 } 194 RF_ASSERT(row >= 0 && row <= raidPtr->numRow && col >= 0 && col <= raidPtr->numCol); 195 RF_LOCK_MUTEX(rctrl->eq_mutex); 196 /* q null and count==0 must be equivalent conditions */ 197 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 198 event->next = rctrl->eventQueue; 199 rctrl->eventQueue = event; 200 rctrl->eq_count++; 201 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 202 203 DO_SIGNAL(rctrl); 204 } 205 /* allocates and initializes a recon event descriptor */ 206 static RF_ReconEvent_t * 207 GetReconEventDesc(row, col, arg, type) 208 RF_RowCol_t row; 209 RF_RowCol_t col; 210 void *arg; 211 RF_Revent_t type; 212 { 213 RF_ReconEvent_t *t; 214 215 RF_FREELIST_GET(rf_revent_freelist, t, next, (RF_ReconEvent_t *)); 216 if (t == NULL) 217 return (NULL); 218 t->col = col; 219 t->arg = arg; 220 t->type = type; 221 return (t); 222 } 223 224 void 225 rf_FreeReconEventDesc(event) 226 RF_ReconEvent_t *event; 227 { 228 RF_FREELIST_FREE(rf_revent_freelist, event, next); 229 } 230