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NetBSD/sys/dev/raidframe/rf_sstf.c

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/* $NetBSD: rf_sstf.c,v 1.3 1999/02/05 00:06:17 oster Exp $ */
/*
* Copyright (c) 1995 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Jim Zelenka
*
* 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.
*/
/*******************************************************************************
*
* sstf.c -- prioritized shortest seek time first disk queueing code
*
******************************************************************************/
#include "rf_alloclist.h"
#include "rf_stripelocks.h"
#include "rf_layout.h"
#include "rf_diskqueue.h"
#include "rf_sstf.h"
#include "rf_debugMem.h"
#include "rf_general.h"
#include "rf_threadid.h"
#include "rf_options.h"
#define DIR_LEFT 1
#define DIR_RIGHT 2
#define DIR_EITHER 3
#define SNUM_DIFF(_a_,_b_) (((_a_)>(_b_))?((_a_)-(_b_)):((_b_)-(_a_)))
#define QSUM(_sstfq_) (((_sstfq_)->lopri.qlen)+((_sstfq_)->left.qlen)+((_sstfq_)->right.qlen))
static void
do_sstf_ord_q(RF_DiskQueueData_t **,
RF_DiskQueueData_t **,
RF_DiskQueueData_t *);
static RF_DiskQueueData_t *
closest_to_arm(RF_SstfQ_t *,
RF_SectorNum_t,
int *,
int);
static void do_dequeue(RF_SstfQ_t *, RF_DiskQueueData_t *);
static void
do_sstf_ord_q(queuep, tailp, req)
RF_DiskQueueData_t **queuep;
RF_DiskQueueData_t **tailp;
RF_DiskQueueData_t *req;
{
RF_DiskQueueData_t *r, *s;
if (*queuep == NULL) {
*queuep = req;
*tailp = req;
req->next = NULL;
req->prev = NULL;
return;
}
if (req->sectorOffset <= (*queuep)->sectorOffset) {
req->next = *queuep;
req->prev = NULL;
(*queuep)->prev = req;
*queuep = req;
return;
}
if (req->sectorOffset > (*tailp)->sectorOffset) {
/* optimization */
r = NULL;
s = *tailp;
goto q_at_end;
}
for (s = NULL, r = *queuep; r; s = r, r = r->next) {
if (r->sectorOffset >= req->sectorOffset) {
/* insert after s, before r */
RF_ASSERT(s);
req->next = r;
r->prev = req;
s->next = req;
req->prev = s;
return;
}
}
q_at_end:
/* insert after s, at end of queue */
RF_ASSERT(r == NULL);
RF_ASSERT(s);
RF_ASSERT(s == (*tailp));
req->next = NULL;
req->prev = s;
s->next = req;
*tailp = req;
}
/* for removing from head-of-queue */
#define DO_HEAD_DEQ(_r_,_q_) { \
_r_ = (_q_)->queue; \
RF_ASSERT((_r_) != NULL); \
(_q_)->queue = (_r_)->next; \
(_q_)->qlen--; \
if ((_q_)->qlen == 0) { \
RF_ASSERT((_r_) == (_q_)->qtail); \
RF_ASSERT((_q_)->queue == NULL); \
(_q_)->qtail = NULL; \
} \
else { \
RF_ASSERT((_q_)->queue->prev == (_r_)); \
(_q_)->queue->prev = NULL; \
} \
}
/* for removing from end-of-queue */
#define DO_TAIL_DEQ(_r_,_q_) { \
_r_ = (_q_)->qtail; \
RF_ASSERT((_r_) != NULL); \
(_q_)->qtail = (_r_)->prev; \
(_q_)->qlen--; \
if ((_q_)->qlen == 0) { \
RF_ASSERT((_r_) == (_q_)->queue); \
RF_ASSERT((_q_)->qtail == NULL); \
(_q_)->queue = NULL; \
} \
else { \
RF_ASSERT((_q_)->qtail->next == (_r_)); \
(_q_)->qtail->next = NULL; \
} \
}
#define DO_BEST_DEQ(_l_,_r_,_q_) { \
if (SNUM_DIFF((_q_)->queue->sectorOffset,_l_) \
< SNUM_DIFF((_q_)->qtail->sectorOffset,_l_)) \
{ \
DO_HEAD_DEQ(_r_,_q_); \
} \
else { \
DO_TAIL_DEQ(_r_,_q_); \
} \
}
static RF_DiskQueueData_t *
closest_to_arm(queue, arm_pos, dir, allow_reverse)
RF_SstfQ_t *queue;
RF_SectorNum_t arm_pos;
int *dir;
int allow_reverse;
{
RF_SectorNum_t best_pos_l = 0, this_pos_l = 0, last_pos = 0;
RF_SectorNum_t best_pos_r = 0, this_pos_r = 0;
RF_DiskQueueData_t *r, *best_l, *best_r;
best_r = best_l = NULL;
for (r = queue->queue; r; r = r->next) {
if (r->sectorOffset < arm_pos) {
if (best_l == NULL) {
best_l = r;
last_pos = best_pos_l = this_pos_l;
} else {
this_pos_l = arm_pos - r->sectorOffset;
if (this_pos_l < best_pos_l) {
best_l = r;
last_pos = best_pos_l = this_pos_l;
} else {
last_pos = this_pos_l;
}
}
} else {
if (best_r == NULL) {
best_r = r;
last_pos = best_pos_r = this_pos_r;
} else {
this_pos_r = r->sectorOffset - arm_pos;
if (this_pos_r < best_pos_r) {
best_r = r;
last_pos = best_pos_r = this_pos_r;
} else {
last_pos = this_pos_r;
}
if (this_pos_r > last_pos) {
/* getting farther away */
break;
}
}
}
}
if ((best_r == NULL) && (best_l == NULL))
return (NULL);
if ((*dir == DIR_RIGHT) && best_r)
return (best_r);
if ((*dir == DIR_LEFT) && best_l)
return (best_l);
if (*dir == DIR_EITHER) {
if (best_l == NULL)
return (best_r);
if (best_r == NULL)
return (best_l);
if (best_pos_r < best_pos_l)
return (best_r);
else
return (best_l);
}
/*
* Nothing in the direction we want to go. Reverse or
* reset the arm. We know we have an I/O in the other
* direction.
*/
if (allow_reverse) {
if (*dir == DIR_RIGHT) {
*dir = DIR_LEFT;
return (best_l);
} else {
*dir = DIR_RIGHT;
return (best_r);
}
}
/*
* Reset (beginning of queue).
*/
RF_ASSERT(*dir == DIR_RIGHT);
return (queue->queue);
}
void *
rf_SstfCreate(sect_per_disk, cl_list, listp)
RF_SectorCount_t sect_per_disk;
RF_AllocListElem_t *cl_list;
RF_ShutdownList_t **listp;
{
RF_Sstf_t *sstfq;
RF_CallocAndAdd(sstfq, 1, sizeof(RF_Sstf_t), (RF_Sstf_t *), cl_list);
sstfq->dir = DIR_EITHER;
sstfq->allow_reverse = 1;
return ((void *) sstfq);
}
void *
rf_ScanCreate(sect_per_disk, cl_list, listp)
RF_SectorCount_t sect_per_disk;
RF_AllocListElem_t *cl_list;
RF_ShutdownList_t **listp;
{
RF_Sstf_t *scanq;
RF_CallocAndAdd(scanq, 1, sizeof(RF_Sstf_t), (RF_Sstf_t *), cl_list);
scanq->dir = DIR_RIGHT;
scanq->allow_reverse = 1;
return ((void *) scanq);
}
void *
rf_CscanCreate(sect_per_disk, cl_list, listp)
RF_SectorCount_t sect_per_disk;
RF_AllocListElem_t *cl_list;
RF_ShutdownList_t **listp;
{
RF_Sstf_t *cscanq;
RF_CallocAndAdd(cscanq, 1, sizeof(RF_Sstf_t), (RF_Sstf_t *), cl_list);
cscanq->dir = DIR_RIGHT;
return ((void *) cscanq);
}
void
rf_SstfEnqueue(qptr, req, priority)
void *qptr;
RF_DiskQueueData_t *req;
int priority;
{
RF_Sstf_t *sstfq;
sstfq = (RF_Sstf_t *) qptr;
if (priority == RF_IO_LOW_PRIORITY) {
if (rf_sstfDebug || rf_scanDebug || rf_cscanDebug) {
RF_DiskQueue_t *dq;
int tid;
rf_get_threadid(tid);
dq = (RF_DiskQueue_t *) req->queue;
printf("[%d] ENQ lopri %d,%d queues are %d,%d,%d\n",
tid, dq->row, dq->col, sstfq->left.qlen, sstfq->right.qlen,
sstfq->lopri.qlen);
}
do_sstf_ord_q(&sstfq->lopri.queue, &sstfq->lopri.qtail, req);
sstfq->lopri.qlen++;
} else {
if (req->sectorOffset < sstfq->last_sector) {
do_sstf_ord_q(&sstfq->left.queue, &sstfq->left.qtail, req);
sstfq->left.qlen++;
} else {
do_sstf_ord_q(&sstfq->right.queue, &sstfq->right.qtail, req);
sstfq->right.qlen++;
}
}
}
static void
do_dequeue(queue, req)
RF_SstfQ_t *queue;
RF_DiskQueueData_t *req;
{
RF_DiskQueueData_t *req2;
if (rf_sstfDebug || rf_scanDebug || rf_cscanDebug) {
int tid;
rf_get_threadid(tid);
printf("[%d] do_dequeue\n", tid);
}
if (req == queue->queue) {
DO_HEAD_DEQ(req2, queue);
RF_ASSERT(req2 == req);
} else
if (req == queue->qtail) {
DO_TAIL_DEQ(req2, queue);
RF_ASSERT(req2 == req);
} else {
/* dequeue from middle of list */
RF_ASSERT(req->next);
RF_ASSERT(req->prev);
queue->qlen--;
req->next->prev = req->prev;
req->prev->next = req->next;
req->next = req->prev = NULL;
}
}
RF_DiskQueueData_t *
rf_SstfDequeue(qptr)
void *qptr;
{
RF_DiskQueueData_t *req = NULL;
RF_Sstf_t *sstfq;
sstfq = (RF_Sstf_t *) qptr;
if (rf_sstfDebug) {
RF_DiskQueue_t *dq;
int tid;
rf_get_threadid(tid);
dq = (RF_DiskQueue_t *) req->queue;
RF_ASSERT(QSUM(sstfq) == dq->queueLength);
printf("[%d] sstf: Dequeue %d,%d queues are %d,%d,%d\n", tid,
dq->row, dq->col, sstfq->left.qlen, sstfq->right.qlen,
sstfq->lopri.qlen);
}
if (sstfq->left.queue == NULL) {
RF_ASSERT(sstfq->left.qlen == 0);
if (sstfq->right.queue == NULL) {
RF_ASSERT(sstfq->right.qlen == 0);
if (sstfq->lopri.queue == NULL) {
RF_ASSERT(sstfq->lopri.qlen == 0);
return (NULL);
}
if (rf_sstfDebug) {
int tid;
rf_get_threadid(tid);
printf("[%d] sstf: check for close lopri", tid);
}
req = closest_to_arm(&sstfq->lopri, sstfq->last_sector,
&sstfq->dir, sstfq->allow_reverse);
if (rf_sstfDebug) {
int tid;
rf_get_threadid(tid);
printf("[%d] sstf: closest_to_arm said %lx", tid, (long) req);
}
if (req == NULL)
return (NULL);
do_dequeue(&sstfq->lopri, req);
} else {
DO_BEST_DEQ(sstfq->last_sector, req, &sstfq->right);
}
} else {
if (sstfq->right.queue == NULL) {
RF_ASSERT(sstfq->right.qlen == 0);
DO_BEST_DEQ(sstfq->last_sector, req, &sstfq->left);
} else {
if (SNUM_DIFF(sstfq->last_sector, sstfq->right.queue->sectorOffset)
< SNUM_DIFF(sstfq->last_sector, sstfq->left.qtail->sectorOffset)) {
DO_HEAD_DEQ(req, &sstfq->right);
} else {
DO_TAIL_DEQ(req, &sstfq->left);
}
}
}
RF_ASSERT(req);
sstfq->last_sector = req->sectorOffset;
return (req);
}
RF_DiskQueueData_t *
rf_ScanDequeue(qptr)
void *qptr;
{
RF_DiskQueueData_t *req = NULL;
RF_Sstf_t *scanq;
scanq = (RF_Sstf_t *) qptr;
if (rf_scanDebug) {
RF_DiskQueue_t *dq;
int tid;
rf_get_threadid(tid);
dq = (RF_DiskQueue_t *) req->queue;
RF_ASSERT(QSUM(scanq) == dq->queueLength);
printf("[%d] scan: Dequeue %d,%d queues are %d,%d,%d\n", tid,
dq->row, dq->col, scanq->left.qlen, scanq->right.qlen,
scanq->lopri.qlen);
}
if (scanq->left.queue == NULL) {
RF_ASSERT(scanq->left.qlen == 0);
if (scanq->right.queue == NULL) {
RF_ASSERT(scanq->right.qlen == 0);
if (scanq->lopri.queue == NULL) {
RF_ASSERT(scanq->lopri.qlen == 0);
return (NULL);
}
req = closest_to_arm(&scanq->lopri, scanq->last_sector,
&scanq->dir, scanq->allow_reverse);
if (req == NULL)
return (NULL);
do_dequeue(&scanq->lopri, req);
} else {
scanq->dir = DIR_RIGHT;
DO_HEAD_DEQ(req, &scanq->right);
}
} else
if (scanq->right.queue == NULL) {
RF_ASSERT(scanq->right.qlen == 0);
RF_ASSERT(scanq->left.queue);
scanq->dir = DIR_LEFT;
DO_TAIL_DEQ(req, &scanq->left);
} else {
RF_ASSERT(scanq->right.queue);
RF_ASSERT(scanq->left.queue);
if (scanq->dir == DIR_RIGHT) {
DO_HEAD_DEQ(req, &scanq->right);
} else {
DO_TAIL_DEQ(req, &scanq->left);
}
}
RF_ASSERT(req);
scanq->last_sector = req->sectorOffset;
return (req);
}
RF_DiskQueueData_t *
rf_CscanDequeue(qptr)
void *qptr;
{
RF_DiskQueueData_t *req = NULL;
RF_Sstf_t *cscanq;
cscanq = (RF_Sstf_t *) qptr;
RF_ASSERT(cscanq->dir == DIR_RIGHT);
if (rf_cscanDebug) {
RF_DiskQueue_t *dq;
int tid;
rf_get_threadid(tid);
dq = (RF_DiskQueue_t *) req->queue;
RF_ASSERT(QSUM(cscanq) == dq->queueLength);
printf("[%d] scan: Dequeue %d,%d queues are %d,%d,%d\n", tid,
dq->row, dq->col, cscanq->left.qlen, cscanq->right.qlen,
cscanq->lopri.qlen);
}
if (cscanq->right.queue) {
DO_HEAD_DEQ(req, &cscanq->right);
} else {
RF_ASSERT(cscanq->right.qlen == 0);
if (cscanq->left.queue == NULL) {
RF_ASSERT(cscanq->left.qlen == 0);
if (cscanq->lopri.queue == NULL) {
RF_ASSERT(cscanq->lopri.qlen == 0);
return (NULL);
}
req = closest_to_arm(&cscanq->lopri, cscanq->last_sector,
&cscanq->dir, cscanq->allow_reverse);
if (req == NULL)
return (NULL);
do_dequeue(&cscanq->lopri, req);
} else {
/*
* There's I/Os to the left of the arm. Swing
* on back (swap queues).
*/
cscanq->right = cscanq->left;
cscanq->left.qlen = 0;
cscanq->left.queue = cscanq->left.qtail = NULL;
DO_HEAD_DEQ(req, &cscanq->right);
}
}
RF_ASSERT(req);
cscanq->last_sector = req->sectorOffset;
return (req);
}
RF_DiskQueueData_t *
rf_SstfPeek(qptr)
void *qptr;
{
RF_DiskQueueData_t *req;
RF_Sstf_t *sstfq;
sstfq = (RF_Sstf_t *) qptr;
if ((sstfq->left.queue == NULL) && (sstfq->right.queue == NULL)) {
req = closest_to_arm(&sstfq->lopri, sstfq->last_sector, &sstfq->dir,
sstfq->allow_reverse);
} else {
if (sstfq->left.queue == NULL)
req = sstfq->right.queue;
else {
if (sstfq->right.queue == NULL)
req = sstfq->left.queue;
else {
if (SNUM_DIFF(sstfq->last_sector, sstfq->right.queue->sectorOffset)
< SNUM_DIFF(sstfq->last_sector, sstfq->left.qtail->sectorOffset)) {
req = sstfq->right.queue;
} else {
req = sstfq->left.qtail;
}
}
}
}
if (req == NULL) {
RF_ASSERT(QSUM(sstfq) == 0);
}
return (req);
}
RF_DiskQueueData_t *
rf_ScanPeek(qptr)
void *qptr;
{
RF_DiskQueueData_t *req;
RF_Sstf_t *scanq;
int dir;
scanq = (RF_Sstf_t *) qptr;
dir = scanq->dir;
if (scanq->left.queue == NULL) {
RF_ASSERT(scanq->left.qlen == 0);
if (scanq->right.queue == NULL) {
RF_ASSERT(scanq->right.qlen == 0);
if (scanq->lopri.queue == NULL) {
RF_ASSERT(scanq->lopri.qlen == 0);
return (NULL);
}
req = closest_to_arm(&scanq->lopri, scanq->last_sector,
&dir, scanq->allow_reverse);
} else {
req = scanq->right.queue;
}
} else
if (scanq->right.queue == NULL) {
RF_ASSERT(scanq->right.qlen == 0);
RF_ASSERT(scanq->left.queue);
req = scanq->left.qtail;
} else {
RF_ASSERT(scanq->right.queue);
RF_ASSERT(scanq->left.queue);
if (scanq->dir == DIR_RIGHT) {
req = scanq->right.queue;
} else {
req = scanq->left.qtail;
}
}
if (req == NULL) {
RF_ASSERT(QSUM(scanq) == 0);
}
return (req);
}
RF_DiskQueueData_t *
rf_CscanPeek(qptr)
void *qptr;
{
RF_DiskQueueData_t *req;
RF_Sstf_t *cscanq;
cscanq = (RF_Sstf_t *) qptr;
RF_ASSERT(cscanq->dir == DIR_RIGHT);
if (cscanq->right.queue) {
req = cscanq->right.queue;
} else {
RF_ASSERT(cscanq->right.qlen == 0);
if (cscanq->left.queue == NULL) {
RF_ASSERT(cscanq->left.qlen == 0);
if (cscanq->lopri.queue == NULL) {
RF_ASSERT(cscanq->lopri.qlen == 0);
return (NULL);
}
req = closest_to_arm(&cscanq->lopri, cscanq->last_sector,
&cscanq->dir, cscanq->allow_reverse);
} else {
/*
* There's I/Os to the left of the arm. We'll end
* up swinging on back.
*/
req = cscanq->left.queue;
}
}
if (req == NULL) {
RF_ASSERT(QSUM(cscanq) == 0);
}
return (req);
}
int
rf_SstfPromote(qptr, parityStripeID, which_ru)
void *qptr;
RF_StripeNum_t parityStripeID;
RF_ReconUnitNum_t which_ru;
{
RF_DiskQueueData_t *r, *next;
RF_Sstf_t *sstfq;
int n;
sstfq = (RF_Sstf_t *) qptr;
n = 0;
if (rf_sstfDebug || rf_scanDebug || rf_cscanDebug) {
int tid;
rf_get_threadid(tid);
printf("[%d] promote %ld %d queues are %d,%d,%d\n",
tid, (long) parityStripeID, (int) which_ru,
sstfq->left.qlen,
sstfq->right.qlen,
sstfq->lopri.qlen);
}
for (r = sstfq->lopri.queue; r; r = next) {
next = r->next;
if (rf_sstfDebug || rf_scanDebug || rf_cscanDebug) {
int tid;
rf_get_threadid(tid);
printf("[%d] check promote %lx\n", tid, (long) r);
}
if ((r->parityStripeID == parityStripeID)
&& (r->which_ru == which_ru)) {
do_dequeue(&sstfq->lopri, r);
rf_SstfEnqueue(qptr, r, RF_IO_NORMAL_PRIORITY);
n++;
}
}
if (rf_sstfDebug || rf_scanDebug || rf_cscanDebug) {
int tid;
rf_get_threadid(tid);
printf("[%d] promoted %d matching I/Os queues are %d,%d,%d\n",
tid, n, sstfq->left.qlen, sstfq->right.qlen, sstfq->lopri.qlen);
}
return (n);
}
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