1 /* $NetBSD: rf_revent.c,v 1.11 2002/09/14 17:54:00 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 1.11 2002/09/14 17:54:00 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_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_print_unable_to_add_shutdown(__FILE__, __LINE__, rc); 87 rf_ShutdownReconEvent(NULL); 88 return (rc); 89 } 90 RF_FREELIST_PRIME(rf_revent_freelist, RF_REVENT_INITIAL, next, 91 (RF_ReconEvent_t *)); 92 return (0); 93 } 94 95 /* returns the next reconstruction event, blocking the calling thread 96 * until one becomes available. will now return null if it is blocked 97 * or will return an event if it is not */ 98 99 RF_ReconEvent_t * 100 rf_GetNextReconEvent(reconDesc, row, continueFunc, continueArg) 101 RF_RaidReconDesc_t *reconDesc; 102 RF_RowCol_t row; 103 void (*continueFunc) (void *); 104 void *continueArg; 105 { 106 RF_Raid_t *raidPtr = reconDesc->raidPtr; 107 RF_ReconCtrl_t *rctrl = raidPtr->reconControl[row]; 108 RF_ReconEvent_t *event; 109 110 RF_ASSERT(row >= 0 && row <= raidPtr->numRow); 111 RF_LOCK_MUTEX(rctrl->eq_mutex); 112 /* q null and count==0 must be equivalent conditions */ 113 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 114 115 rctrl->continueFunc = continueFunc; 116 rctrl->continueArg = continueArg; 117 118 119 /* mpsleep timeout value: secs = timo_val/hz. 'ticks' here is 120 defined as cycle-counter ticks, not softclock ticks */ 121 122 #define MAX_RECON_EXEC_USECS (100 * 1000) /* 100 ms */ 123 #define RECON_DELAY_MS 25 124 #define RECON_TIMO ((RECON_DELAY_MS * hz) / 1000) 125 126 /* we are not pre-emptible in the kernel, but we don't want to run 127 * forever. If we run w/o blocking for more than MAX_RECON_EXEC_TICKS 128 * ticks of the cycle counter, delay for RECON_DELAY before 129 * continuing. this may murder us with context switches, so we may 130 * need to increase both the MAX...TICKS and the RECON_DELAY_MS. */ 131 if (reconDesc->reconExecTimerRunning) { 132 int status; 133 134 RF_ETIMER_STOP(reconDesc->recon_exec_timer); 135 RF_ETIMER_EVAL(reconDesc->recon_exec_timer); 136 reconDesc->reconExecTicks += 137 RF_ETIMER_VAL_US(reconDesc->recon_exec_timer); 138 if (reconDesc->reconExecTicks > reconDesc->maxReconExecTicks) 139 reconDesc->maxReconExecTicks = 140 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 */ 147 148 status = ltsleep(&reconDesc->reconExecTicks, PRIBIO, 149 "recon delay", RECON_TIMO, 150 &rctrl->eq_mutex); 151 RF_ASSERT(status == EWOULDBLOCK); 152 reconDesc->reconExecTicks = 0; 153 } 154 } 155 while (!rctrl->eventQueue) { 156 #if RF_RECON_STATS > 0 157 reconDesc->numReconEventWaits++; 158 #endif /* RF_RECON_STATS > 0 */ 159 DO_WAIT(rctrl); 160 reconDesc->reconExecTicks = 0; /* we've just waited */ 161 } 162 163 reconDesc->reconExecTimerRunning = 1; 164 if (RF_ETIMER_VAL_US(reconDesc->recon_exec_timer)!=0) { 165 /* it moved!! reset the timer. */ 166 RF_ETIMER_START(reconDesc->recon_exec_timer); 167 } 168 event = rctrl->eventQueue; 169 rctrl->eventQueue = event->next; 170 event->next = NULL; 171 rctrl->eq_count--; 172 173 /* q null and count==0 must be equivalent conditions */ 174 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 175 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 176 return (event); 177 } 178 /* enqueues a reconstruction event on the indicated queue */ 179 void 180 rf_CauseReconEvent(raidPtr, row, col, arg, type) 181 RF_Raid_t *raidPtr; 182 RF_RowCol_t row; 183 RF_RowCol_t col; 184 void *arg; 185 RF_Revent_t type; 186 { 187 RF_ReconCtrl_t *rctrl = raidPtr->reconControl[row]; 188 RF_ReconEvent_t *event = GetReconEventDesc(row, col, arg, type); 189 190 if (type == RF_REVENT_BUFCLEAR) { 191 RF_ASSERT(col != rctrl->fcol); 192 } 193 RF_ASSERT(row >= 0 && row <= raidPtr->numRow && col >= 0 && col <= raidPtr->numCol); 194 RF_LOCK_MUTEX(rctrl->eq_mutex); 195 /* q null and count==0 must be equivalent conditions */ 196 RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); 197 event->next = rctrl->eventQueue; 198 rctrl->eventQueue = event; 199 rctrl->eq_count++; 200 RF_UNLOCK_MUTEX(rctrl->eq_mutex); 201 202 DO_SIGNAL(rctrl); 203 } 204 /* allocates and initializes a recon event descriptor */ 205 static RF_ReconEvent_t * 206 GetReconEventDesc(row, col, arg, type) 207 RF_RowCol_t row; 208 RF_RowCol_t col; 209 void *arg; 210 RF_Revent_t type; 211 { 212 RF_ReconEvent_t *t; 213 214 RF_FREELIST_GET(rf_revent_freelist, t, next, (RF_ReconEvent_t *)); 215 if (t == NULL) 216 return (NULL); 217 t->col = col; 218 t->arg = arg; 219 t->type = type; 220 return (t); 221 } 222 223 void 224 rf_FreeReconEventDesc(event) 225 RF_ReconEvent_t *event; 226 { 227 RF_FREELIST_FREE(rf_revent_freelist, event, next); 228 } 229