NetBSD/sys/dev/raidframe/rf_revent.c

214 lines
6.2 KiB
C

/* $NetBSD: rf_revent.c,v 1.22 2005/12/11 12:23:37 christos 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rf_revent.c,v 1.22 2005/12/11 12:23:37 christos Exp $");
#include <sys/errno.h>
#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
#include <sys/proc.h>
#include <sys/kernel.h>
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;
RF_LOCK_MUTEX(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 = ltsleep(&reconDesc->reconExecTicks, PRIBIO,
"recon delay", RECON_TIMO,
&rctrl->eq_mutex);
RF_ASSERT(status == EWOULDBLOCK);
reconDesc->reconExecTicks = 0;
}
}
while (!rctrl->eventQueue) {
#if RF_RECON_STATS > 0
reconDesc->numReconEventWaits++;
#endif /* RF_RECON_STATS > 0 */
ltsleep(&(rctrl)->eventQueue, PRIBIO, "raidframe eventq",
0, &((rctrl)->eq_mutex));
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_MUTEX(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_MUTEX(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_UNLOCK_MUTEX(rctrl->eq_mutex);
wakeup(&(rctrl)->eventQueue);
}
/* 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_MUTEX(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_MUTEX(rctrl->eq_mutex);
}
void
rf_FreeReconEventDesc(RF_ReconEvent_t *event)
{
pool_put(&rf_pools.revent, event);
}