double ssd_clean_element_no_copyback(int elem_num, ssd_t *s)
{
double cost = 0;
if (!ssd_start_cleaning(-1, elem_num, s)) {
return cost;
}
switch(s->params.cleaning_policy) {
case DISKSIM_SSD_CLEANING_POLICY_RANDOM:
cost = ssd_clean_blocks_random(-1, elem_num, s);
break;
case DISKSIM_SSD_CLEANING_POLICY_GREEDY_WEAR_AGNOSTIC:
case DISKSIM_SSD_CLEANING_POLICY_GREEDY_WEAR_AWARE:
cost = ssd_clean_blocks_greedy(-1, elem_num, s);
break;
default:
fprintf(stderr, "Error: invalid cleaning policy %d\n",
s->params.cleaning_policy);
exit(1);
}
return cost;
}
static double ssd_write_one_active_page(int blkno, int count, int elem_num, ssd_t *s)
{
double cost = 0;
int cleaning_invoked = 0;
ssd_element_metadata *metadata;
ssd_power_element_stat *power_stat;
int lbn;
metadata = &(s->elements[elem_num].metadata);
power_stat = &(s->elements[elem_num].power_stat);
// get the logical page number corresponding to this blkno
lbn = ssd_logical_pageno(blkno, s);
// see if there are any free pages left inside the active block.
// as per the osr design, the last page is used as a summary page.
// so if the active_page is already pointing to the summary page,
// then we need to find another free block to act as active block.
if (ssd_last_page_in_block(metadata->active_block, s)) {
// do we need to create more free blocks for future writes?
if (ssd_start_cleaning(-1, elem_num, s)) {
printf ("We should not clean here ...\n");
ASSERT(0);
// if we're cleaning in the background, this should
// not get executed
if (s->params.cleaning_in_background) {
exit(1);
}
cleaning_invoked = 1;
cost += ssd_clean_element_no_copyback(elem_num, s);
}
// if we had invoked the cleaning, we must again check if we
// need an active block before allocating one. this check is
// needed because the above cleaning procedure might have
// allocated new active blocks during the process of cleaning,
// which might still have free pages for writing.
if (!cleaning_invoked ||
ssd_last_page_in_block(metadata->active_block, s)) {
_ssd_alloc_active_block(-1, elem_num, s);
}
}
// issue the write to the current active page
cost += _ssd_write_page_osr(s, metadata, lbn, power_stat, blkno);
cost += ssd_data_transfer_cost(s, count);
ssd_power_flash_calculate(SSD_POWER_FLASH_BUS_DATA_TRANSFER, ssd_data_transfer_cost(s,s->params.page_size), power_stat, s);
return cost;
}
int ssd_start_cleaning_parunit(int parunit_num, int elem_num, ssd_t *s)
{
int i;
int start;
start = s->elements[elem_num].metadata.parunits[parunit_num].plane_to_clean;
i = start;
do {
ASSERT(parunit_num == s->elements[elem_num].metadata.plane_meta[i].parunit_num);
if (ssd_start_cleaning(i, elem_num, s)) {
s->elements[elem_num].metadata.parunits[parunit_num].plane_to_clean = \
ssd_next_plane_in_parunit(i, parunit_num, elem_num, s);
return i;
}
i = ssd_next_plane_in_parunit(i, parunit_num, elem_num, s);
} while (i != start);
return -1;
}
