/*
* computes the time taken to read/write data in a flash element
* using just one active page.
*/
static void ssd_compute_access_time_one_active_page
(ssd_req **reqs, int total, int elem_num, ssd_t *s)
{
// we assume that requests have been broken down into page sized chunks
double cost;
int blkno;
int count;
int is_read;
ssd_power_element_stat *power_stat = &(s->elements[elem_num].power_stat);
// we can serve only one request at a time
ASSERT(total == 1);
blkno = reqs[0]->blk;
count = reqs[0]->count;
is_read = reqs[0]->is_read;
if (is_read) {
cost = ssd_read_policy_simple(count, s, power_stat);
} else {
cost = ssd_write_one_active_page(blkno, count, elem_num, s);
}
reqs[0]->acctime = cost;
reqs[0]->schtime = cost;
}
/*
* computes the time taken to read/write data in a flash element
* using just one active page.
*/
static void ssd_compute_access_time_one_active_page
(ssd_req **reqs, int total, int elem_num, ssd_t *s)
{
// we assume that requests have been broken down into page sized chunks
double cost;
int blkno;
int count;
int is_read;
// we can serve only one request at a time
ASSERT(total == 1);
blkno = reqs[0]->blk;
count = reqs[0]->count;
is_read = reqs[0]->is_read;
if (is_read) {
// there are no separate read policies.
switch(s->params.write_policy) {
case DISKSIM_SSD_WRITE_POLICY_SIMPLE:
case DISKSIM_SSD_WRITE_POLICY_OSR:
// the cost of one page read
cost = ssd_read_policy_simple(count, s);
break;
default:
fprintf(stderr, "Error: unknown write policy %d in ssd_compute_access_time\n",
s->params.write_policy);
exit(1);
}
} else {
switch(s->params.write_policy) {
case DISKSIM_SSD_WRITE_POLICY_SIMPLE:
cost = ssd_write_policy_simple(blkno, count, elem_num, s);
break;
case DISKSIM_SSD_WRITE_POLICY_OSR:
cost = ssd_write_one_active_page(blkno, count, elem_num, s);
break;
default:
fprintf(stderr, "Error: unknown write policy %d in ssd_compute_access_time\n",
s->params.write_policy);
exit(1);
}
}
reqs[0]->acctime = cost;
reqs[0]->schtime = cost;
}
