/* $NetBSD: rf_revent.c,v 1.28 2011/05/02 01:07:24 mrg Exp $ */ /* * Copyright (c) 1995 Carnegie-Mellon University. * All rights reserved. * * Author: * * Permission to use, copy, modify and distribute this software and * its documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. */ /* * revent.c -- reconstruction event handling code */ #include __KERNEL_RCSID(0, "$NetBSD: rf_revent.c,v 1.28 2011/05/02 01:07:24 mrg Exp $"); #include #include "rf_raid.h" #include "rf_revent.h" #include "rf_etimer.h" #include "rf_general.h" #include "rf_desc.h" #include "rf_shutdown.h" #define RF_MAX_FREE_REVENT 128 #define RF_MIN_FREE_REVENT 32 #define RF_EVENTQ_WAIT 5000 #include #include static void rf_ShutdownReconEvent(void *); static RF_ReconEvent_t * GetReconEventDesc(RF_RowCol_t col, void *arg, RF_Revent_t type); static void rf_ShutdownReconEvent(void *ignored) { pool_destroy(&rf_pools.revent); } int rf_ConfigureReconEvent(RF_ShutdownList_t **listp) { rf_pool_init(&rf_pools.revent, sizeof(RF_ReconEvent_t), "rf_revent_pl", RF_MIN_FREE_REVENT, RF_MAX_FREE_REVENT); rf_ShutdownCreate(listp, rf_ShutdownReconEvent, NULL); return (0); } /* returns the next reconstruction event, blocking the calling thread * until one becomes available. will now return null if it is blocked * or will return an event if it is not */ RF_ReconEvent_t * rf_GetNextReconEvent(RF_RaidReconDesc_t *reconDesc) { RF_Raid_t *raidPtr = reconDesc->raidPtr; RF_ReconCtrl_t *rctrl = raidPtr->reconControl; RF_ReconEvent_t *event; int stall_count; rf_lock_mutex2(rctrl->eq_mutex); /* q null and count==0 must be equivalent conditions */ RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); /* mpsleep timeout value: secs = timo_val/hz. 'ticks' here is defined as cycle-counter ticks, not softclock ticks */ #define MAX_RECON_EXEC_USECS (100 * 1000) /* 100 ms */ #define RECON_DELAY_MS 25 #define RECON_TIMO ((RECON_DELAY_MS * hz) / 1000) /* we are not pre-emptible in the kernel, but we don't want to run * forever. If we run w/o blocking for more than MAX_RECON_EXEC_TICKS * ticks of the cycle counter, delay for RECON_DELAY before * continuing. this may murder us with context switches, so we may * need to increase both the MAX...TICKS and the RECON_DELAY_MS. */ if (reconDesc->reconExecTimerRunning) { int status; RF_ETIMER_STOP(reconDesc->recon_exec_timer); RF_ETIMER_EVAL(reconDesc->recon_exec_timer); reconDesc->reconExecTicks += RF_ETIMER_VAL_US(reconDesc->recon_exec_timer); if (reconDesc->reconExecTicks > reconDesc->maxReconExecTicks) reconDesc->maxReconExecTicks = reconDesc->reconExecTicks; if (reconDesc->reconExecTicks >= MAX_RECON_EXEC_USECS) { /* we've been running too long. delay for * RECON_DELAY_MS */ #if RF_RECON_STATS > 0 reconDesc->numReconExecDelays++; #endif /* RF_RECON_STATS > 0 */ status = rf_sleep("rfrecond", RECON_TIMO, rctrl->eq_mutex); RF_ASSERT(status == EWOULDBLOCK); reconDesc->reconExecTicks = 0; } } stall_count = 0; while (!rctrl->eventQueue) { #if RF_RECON_STATS > 0 reconDesc->numReconEventWaits++; #endif /* RF_RECON_STATS > 0 */ rf_timedwait_cond2(rctrl->eq_cv, rctrl->eq_mutex, RF_EVENTQ_WAIT); stall_count++; if ((stall_count > 10) && rctrl->headSepCBList) { /* There is work to do on the callback list, and we've waited long enough... */ rf_WakeupHeadSepCBWaiters(raidPtr); stall_count = 0; } reconDesc->reconExecTicks = 0; /* we've just waited */ } reconDesc->reconExecTimerRunning = 1; if (RF_ETIMER_VAL_US(reconDesc->recon_exec_timer)!=0) { /* it moved!! reset the timer. */ RF_ETIMER_START(reconDesc->recon_exec_timer); } event = rctrl->eventQueue; rctrl->eventQueue = event->next; event->next = NULL; rctrl->eq_count--; /* q null and count==0 must be equivalent conditions */ RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); rf_unlock_mutex2(rctrl->eq_mutex); return (event); } /* enqueues a reconstruction event on the indicated queue */ void rf_CauseReconEvent(RF_Raid_t *raidPtr, RF_RowCol_t col, void *arg, RF_Revent_t type) { RF_ReconCtrl_t *rctrl = raidPtr->reconControl; RF_ReconEvent_t *event = GetReconEventDesc(col, arg, type); if (type == RF_REVENT_BUFCLEAR) { RF_ASSERT(col != rctrl->fcol); } RF_ASSERT(col >= 0 && col <= raidPtr->numCol); rf_lock_mutex2(rctrl->eq_mutex); /* q null and count==0 must be equivalent conditions */ RF_ASSERT((rctrl->eventQueue == NULL) == (rctrl->eq_count == 0)); event->next = rctrl->eventQueue; rctrl->eventQueue = event; rctrl->eq_count++; rf_broadcast_cond2(rctrl->eq_cv); rf_unlock_mutex2(rctrl->eq_mutex); } /* allocates and initializes a recon event descriptor */ static RF_ReconEvent_t * GetReconEventDesc(RF_RowCol_t col, void *arg, RF_Revent_t type) { RF_ReconEvent_t *t; t = pool_get(&rf_pools.revent, PR_WAITOK); t->col = col; t->arg = arg; t->type = type; t->next = NULL; return (t); } /* rf_DrainReconEventQueue() -- used in the event of a reconstruction problem, this function simply drains all pending events from the reconstruct event queue. */ void rf_DrainReconEventQueue(RF_RaidReconDesc_t *reconDesc) { RF_ReconCtrl_t *rctrl = reconDesc->raidPtr->reconControl; RF_ReconEvent_t *event; rf_lock_mutex2(rctrl->eq_mutex); while (rctrl->eventQueue!=NULL) { event = rctrl->eventQueue; rctrl->eventQueue = event->next; event->next = NULL; rctrl->eq_count--; /* dump it */ rf_FreeReconEventDesc(event); } rf_unlock_mutex2(rctrl->eq_mutex); } void rf_FreeReconEventDesc(RF_ReconEvent_t *event) { pool_put(&rf_pools.revent, event); }