RF_DiskQueueData_t *
rf_CvscanDequeue(void *q_in)
{
RF_CvscanHeader_t *hdr = (RF_CvscanHeader_t *) q_in;
long range, i, sum_dist_left, sum_dist_right;
RF_DiskQueueData_t *ret;
RF_DiskQueueData_t *tmp;
DO_CHECK_STATE(hdr);
if (hdr->left_cnt == 0 && hdr->right_cnt == 0)
return ((RF_DiskQueueData_t *) NULL);
range = RF_MIN(hdr->range_for_avg, RF_MIN(hdr->left_cnt, hdr->right_cnt));
for (i = 0, tmp = hdr->left, sum_dist_left =
((hdr->direction == rf_cvscan_RIGHT) ? range * hdr->change_penalty : 0);
tmp != (RF_DiskQueueData_t *) NULL && i < range;
tmp = tmp->next, i++) {
sum_dist_left += hdr->cur_block - tmp->sectorOffset;
}
for (i = 0, tmp = hdr->right, sum_dist_right =
((hdr->direction == rf_cvscan_LEFT) ? range * hdr->change_penalty : 0);
tmp != (RF_DiskQueueData_t *) NULL && i < range;
tmp = tmp->next, i++) {
sum_dist_right += tmp->sectorOffset - hdr->cur_block;
}
if (hdr->right_cnt == 0 || sum_dist_left < sum_dist_right) {
hdr->direction = rf_cvscan_LEFT;
hdr->cur_block = hdr->left->sectorOffset + hdr->left->numSector;
hdr->left_cnt = RF_MAX(hdr->left_cnt - 1, 0);
tmp = hdr->left;
ret = (ReqDequeue(&hdr->left)) /*->parent*/ ;
} else {
hdr->direction = rf_cvscan_RIGHT;
hdr->cur_block = hdr->right->sectorOffset + hdr->right->numSector;
hdr->right_cnt = RF_MAX(hdr->right_cnt - 1, 0);
tmp = hdr->right;
ret = (ReqDequeue(&hdr->right)) /*->parent*/ ;
}
ReBalance(hdr);
if (hdr->left_cnt == 0 && hdr->right_cnt == 0
&& hdr->burner != (RF_DiskQueueData_t *) NULL) {
/*
** restore low priority requests for next dequeue
*/
RF_DiskQueueData_t *burner = hdr->burner;
hdr->nxt_priority = burner->priority;
while (burner != (RF_DiskQueueData_t *) NULL
&& burner->priority == hdr->nxt_priority) {
RF_DiskQueueData_t *next = burner->next;
RealEnqueue(hdr, burner);
burner = next;
}
hdr->burner = burner;
}
DO_CHECK_STATE(hdr);
return (ret);
}
RF_DiskQueueData_t *
rf_CvscanPeek(void *q_in)
{
RF_CvscanHeader_t *hdr = (RF_CvscanHeader_t *) q_in;
long range, i, sum_dist_left, sum_dist_right;
RF_DiskQueueData_t *tmp, *headElement;
DO_CHECK_STATE(hdr);
if (hdr->left_cnt == 0 && hdr->right_cnt == 0)
headElement = NULL;
else {
range = RF_MIN(hdr->range_for_avg, RF_MIN(hdr->left_cnt, hdr->right_cnt));
for (i = 0, tmp = hdr->left, sum_dist_left =
((hdr->direction == rf_cvscan_RIGHT) ? range * hdr->change_penalty : 0);
tmp != (RF_DiskQueueData_t *) NULL && i < range;
tmp = tmp->next, i++) {
sum_dist_left += hdr->cur_block - tmp->sectorOffset;
}
for (i = 0, tmp = hdr->right, sum_dist_right =
((hdr->direction == rf_cvscan_LEFT) ? range * hdr->change_penalty : 0);
tmp != (RF_DiskQueueData_t *) NULL && i < range;
tmp = tmp->next, i++) {
sum_dist_right += tmp->sectorOffset - hdr->cur_block;
}
if (hdr->right_cnt == 0 || sum_dist_left < sum_dist_right)
headElement = hdr->left;
else
headElement = hdr->right;
}
return (headElement);
}
/*
* Promote reconstruction accesses for the given stripeID to normal priority.
* Return 1 if an access was found and zero otherwise.
* Normally, we should only have one or zero entries in the burner queue,
* so execution time should be short.
*/
int
rf_CvscanPromote(void *q_in, RF_StripeNum_t parityStripeID,
RF_ReconUnitNum_t which_ru)
{
RF_CvscanHeader_t *hdr = (RF_CvscanHeader_t *) q_in;
RF_DiskQueueData_t *trailer = NULL, *tmp = hdr->burner, *tlist = NULL;
int retval = 0;
DO_CHECK_STATE(hdr);
while (tmp) { /* Handle entries at the front of the list. */
if (tmp->parityStripeID == parityStripeID &&
tmp->which_ru == which_ru) {
hdr->burner = tmp->next;
tmp->priority = RF_IO_NORMAL_PRIORITY;
tmp->next = tlist;
tlist = tmp;
tmp = hdr->burner;
} else
break;
}
if (tmp) {
trailer = tmp;
tmp = tmp->next;
}
while (tmp) { /* Handle entries on the rest of the list. */
if (tmp->parityStripeID == parityStripeID &&
tmp->which_ru == which_ru) {
trailer->next = tmp->next;
tmp->priority = RF_IO_NORMAL_PRIORITY;
tmp->next = tlist;
tlist = tmp; /* Insert on a temp queue. */
tmp = trailer->next;
} else {
trailer = tmp;
tmp = tmp->next;
}
}
while (tlist) {
retval++;
tmp = tlist->next;
rf_RealEnqueue(hdr, tlist);
tlist = tmp;
}
RF_ASSERT(retval == 0 || retval == 1);
DO_CHECK_STATE((RF_CvscanHeader_t *) q_in);
return (retval);
}
void
rf_RealEnqueue(RF_CvscanHeader_t *hdr, RF_DiskQueueData_t *req)
{
RF_ASSERT(req->priority == RF_IO_NORMAL_PRIORITY ||
req->priority == RF_IO_LOW_PRIORITY);
DO_CHECK_STATE(hdr);
if (hdr->left_cnt == 0 && hdr->right_cnt == 0) {
hdr->nxt_priority = req->priority;
}
if (req->priority > hdr->nxt_priority) {
/*
* Dump all other outstanding requests on the back burner.
*/
rf_Transfer(&hdr->burner, &hdr->left);
rf_Transfer(&hdr->burner, &hdr->right);
hdr->left_cnt = 0;
hdr->right_cnt = 0;
hdr->nxt_priority = req->priority;
}
if (req->priority < hdr->nxt_priority) {
/*
* Yet another low priority task !
*/
rf_PriorityInsert(&hdr->burner, req);
} else {
if (req->sectorOffset < hdr->cur_block) {
/* This request is to the left of the current arms. */
rf_ReqInsert(&hdr->left, req, rf_cvscan_LEFT);
hdr->left_cnt++;
} else {
/* This request is to the right of the current arms. */
rf_ReqInsert(&hdr->right, req, rf_cvscan_RIGHT);
hdr->right_cnt++;
}
}
DO_CHECK_STATE(hdr);
}
void *
rf_CvscanCreate(RF_SectorCount_t sectPerDisk,
RF_AllocListElem_t * clList,
RF_ShutdownList_t ** listp)
{
RF_CvscanHeader_t *hdr;
long range = 2; /* Currently no mechanism to change these */
long penalty = sectPerDisk / 5;
RF_MallocAndAdd(hdr, sizeof(RF_CvscanHeader_t), (RF_CvscanHeader_t *), clList);
bzero((char *) hdr, sizeof(RF_CvscanHeader_t));
hdr->range_for_avg = RF_MAX(range, 1);
hdr->change_penalty = RF_MAX(penalty, 0);
hdr->direction = rf_cvscan_RIGHT;
hdr->cur_block = 0;
hdr->left_cnt = hdr->right_cnt = 0;
hdr->left = hdr->right = (RF_DiskQueueData_t *) NULL;
hdr->burner = (RF_DiskQueueData_t *) NULL;
DO_CHECK_STATE(hdr);
return ((void *) hdr);
}
