/*
* writes a page to the current active page. if there is no active page,
* allocate one and then move.
*/
static double ssd_move_page(int lpn, int from_blk, int plane_num, int elem_num, ssd_t *s)
{
double cost = 0;
ssd_element_metadata *metadata = &s->elements[elem_num].metadata;
switch(s->params.copy_back) {
case SSD_COPY_BACK_DISABLE:
if (ssd_last_page_in_block(metadata->active_page, s)) {
_ssd_alloc_active_block(-1, elem_num, s);
}
break;
case SSD_COPY_BACK_ENABLE:
ASSERT(metadata->plane_meta[plane_num].active_page == metadata->active_page);
if (ssd_last_page_in_block(metadata->active_page, s)) {
_ssd_alloc_active_block(plane_num, elem_num, s);
}
break;
default:
fprintf(stderr, "Error: invalid copy back policy %d\n",
s->params.copy_back);
exit(1);
}
cost += _ssd_write_page_osr(s, metadata, lpn);
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;
}
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;
int offset;
int tmp_block;
int apn;
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_blockno(blkno, s);
apn = blkno/s->params.page_size;
offset = (apn/s->params.nelements)%s->params.pages_per_block;
// check lbn table
if(metadata->lba_table[lbn] == -1 ) {
metadata->lba_table[lbn] = metadata->active_block;
cost += _ssd_write_page_osr(s, metadata, lbn, offset, power_stat);
_ssd_alloc_active_block(-1, elem_num, s);
}
else { //if already mapped, check log block
tmp_block = metadata->lba_table[lbn];
if(metadata->block_usage[tmp_block].page[offset] == -1)
cost += _ssd_write_page_osr(s, metadata, lbn, offset, power_stat);
else {
if (metadata->block_usage[tmp_block].log_index == -1) {
metadata->block_usage[tmp_block].log_index = _ssd_alloc_log_block(-1, elem_num, s, tmp_block);
cost += _ssd_write_log_block_osr(s, metadata, lbn, offset, power_stat);
}
else {
if(_last_page_in_log_block(metadata, s, tmp_block)){
ssd_invoke_logblock_cleaning(s, elem_num, lbn);
metadata->block_usage[tmp_block].log_index = _ssd_alloc_log_block(-1, elem_num, s, tmp_block);
}
cost += _ssd_write_log_block_osr(s, metadata, lbn, offset, power_stat);
}
}
}
// issue the write to the current active page
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;
}
static double ssd_issue_overlapped_ios(ssd_req **reqs, int total, int elem_num, ssd_t *s)
{
double max_cost = 0;
double parunit_op_cost[SSD_MAX_PARUNITS_PER_ELEM];
double parunit_tot_cost[SSD_MAX_PARUNITS_PER_ELEM];
ssd_element_metadata *metadata;
ssd_power_element_stat *power_stat;
int lbn;
int offset;
int i;
int read_cycle = 0;
listnode **parunits;
// all the requests must be of the same type
for (i = 1; i < total; i ++) {
ASSERT(reqs[i]->is_read == reqs[0]->is_read);
}
// is this a set of read requests?
if (reqs[0]->is_read) {
read_cycle = 1;
}
memset(parunit_tot_cost, 0, sizeof(double)*SSD_MAX_PARUNITS_PER_ELEM);
// find the planes to which the reqs are to be issued
metadata = &(s->elements[elem_num].metadata);
power_stat = &(s->elements[elem_num].power_stat);
parunits = ssd_pick_parunits(reqs, total, elem_num, metadata, s);
// repeat until we've served all the requests
while (1) {
double max_op_cost = 0;
double read_xfer_cost = 0.0;
double write_xfer_cost = 0.0;
int active_parunits = 0;
int op_count = 0;
// do we still have any request to service?
for (i = 0; i < SSD_PARUNITS_PER_ELEM(s); i ++) {
if (ll_get_size(parunits[i]) > 0) {
active_parunits ++;
}
}
// no more requests -- get out
if (active_parunits == 0) {
break;
}
// clear this arrays for storing costs
memset(parunit_op_cost, 0, sizeof(double)*SSD_MAX_PARUNITS_PER_ELEM);
// begin a round of serving. we serve one request per
// parallel unit. if an unit has more than one request
// in the list, they have to be serialized.
max_cost = 0;
for (i = 0; i < SSD_PARUNITS_PER_ELEM(s); i ++) {
int size;
size = ll_get_size(parunits[i]);
if (size > 0) {
int apn;
// this parallel unit has a request to serve
ssd_req *r;
listnode *n = ll_get_nth_node(parunits[i], 0);
op_count ++;
ASSERT(op_count <= active_parunits);
// get the request
r = (ssd_req *)n->data;
lbn = ssd_logical_blockno(r->blk, s);
apn = r->blk/s->params.page_size;
offset = (apn/s->params.nelements)%(s->params.pages_per_block-1);
parunit_op_cost[i] = 0;
if (r->is_read) {
int block = metadata->lba_table[lbn];
if(block == -1){
parunit_op_cost[i] = s->params.page_read_latency;
//Micky
ssd_power_flash_calculate(SSD_POWER_FLASH_READ, s->params.page_read_latency, power_stat, s);
}else if(metadata->block_usage[block].log_index == -1){
parunit_op_cost[i] = s->params.page_read_latency;
//Micky
ssd_power_flash_calculate(SSD_POWER_FLASH_READ, s->params.page_read_latency, power_stat, s);
}else{
parunit_op_cost[i] = s->params.page_read_latency;
//Micky
ssd_power_flash_calculate(SSD_POWER_FLASH_READ, s->params.page_read_latency, power_stat, s);
parunit_op_cost[i] += s->params.page_read_latency;
ssd_power_flash_calculate(SSD_POWER_FLASH_READ, s->params.page_read_latency, power_stat, s);
s->spare_read++;
}
//tiel xfer cost
read_xfer_cost += ssd_data_transfer_cost(s,r->count);
} else { //for write
int plane_num = r->plane_num;
// issue the write to the current active page.
// we need to transfer the data across the serial pins for write.
metadata->active_block = metadata->plane_meta[plane_num].active_block;
// check lbn table
if(metadata->lba_table[lbn] == -1 ) {
metadata->lba_table[lbn] = metadata->active_block;
parunit_op_cost[i] = _ssd_write_page_osr(s, metadata, lbn, offset, power_stat);
_ssd_alloc_active_block(plane_num, elem_num, s);
}
else { //if already mapped, check log block
int tmp_block = metadata->lba_table[lbn];
if(metadata->block_usage[tmp_block].page[offset] == -1) {
parunit_op_cost[i] = _ssd_write_page_osr(s, metadata, lbn, offset, power_stat);
}
else {
if (metadata->block_usage[tmp_block].log_index == -1) {
metadata->block_usage[tmp_block].log_index = _ssd_alloc_log_block(plane_num, elem_num, s, tmp_block);
parunit_op_cost[i] = _ssd_write_log_block_osr(s, metadata, lbn, offset, power_stat);
}
else {
if(_last_page_in_log_block(metadata, s, tmp_block)){
int new_block;
parunit_op_cost[i] += ssd_invoke_logblock_cleaning(elem_num, s, lbn);
new_block = metadata->lba_table[lbn];
if(metadata->block_usage[new_block].log_index == -1){
metadata->block_usage[new_block].log_index = _ssd_alloc_log_block(plane_num, elem_num, s, tmp_block);
}
}else{
parunit_op_cost[i] += _ssd_write_log_block_osr(s, metadata, lbn, offset, power_stat);
}
}
}
}
write_xfer_cost += ssd_data_transfer_cost(s,r->count);
}
ASSERT(r->count <= s->params.page_size);
// calc the cost: the access time should be something like this
// for read
if (read_cycle) {
if (SSD_PARUNITS_PER_ELEM(s) > 4) {
printf("modify acc time here ...\n");
ASSERT(0);
}
if (op_count == 1) {
r->acctime = parunit_op_cost[i] + read_xfer_cost;
r->schtime = parunit_tot_cost[i] + r->acctime;
} else {
r->acctime = ssd_data_transfer_cost(s,r->count);
r->schtime = parunit_tot_cost[i] + read_xfer_cost + parunit_op_cost[i];
}
} else {
// for write
r->acctime = parunit_op_cost[i];
r->schtime = parunit_tot_cost[i] + write_xfer_cost + r->acctime;
}
// find the maximum cost for this round of operations
if (max_cost < r->schtime) {
max_cost = r->schtime;
}
// release the node from the linked list
ll_release_node(parunits[i], n);
}
}
ssd_power_flash_calculate(SSD_POWER_FLASH_BUS_DATA_TRANSFER, read_xfer_cost, power_stat, s);
ssd_power_flash_calculate(SSD_POWER_FLASH_BUS_DATA_TRANSFER, write_xfer_cost, power_stat, s);
// we can start the next round of operations only after all
// the operations in the first round are over because we're
// limited by the one set of pins to all the parunits
for (i = 0; i < SSD_PARUNITS_PER_ELEM(s); i ++) {
parunit_tot_cost[i] = max_cost;
}
}
for (i = 0; i < SSD_PARUNITS_PER_ELEM(s); i ++) {
ll_release(parunits[i]);
}
free(parunits);
power_stat->acc_time += max_cost;
return max_cost;
}
static double ssd_issue_overlapped_ios(ssd_req **reqs, int total, int elem_num, ssd_t *s)
{
double max_cost = 0;
double parunit_op_cost[SSD_MAX_PARUNITS_PER_ELEM];
double parunit_tot_cost[SSD_MAX_PARUNITS_PER_ELEM];
ssd_element_metadata *metadata;
int lpn;
int i;
int read_cycle = 0;
listnode **parunits;
// all the requests must be of the same type
for (i = 1; i < total; i ++) {
ASSERT(reqs[i]->is_read == reqs[0]->is_read);
}
// is this a set of read requests?
if (reqs[0]->is_read) {
read_cycle = 1;
}
memset(parunit_tot_cost, 0, sizeof(double)*SSD_MAX_PARUNITS_PER_ELEM);
// find the planes to which the reqs are to be issued
metadata = &(s->elements[elem_num].metadata);
parunits = ssd_pick_parunits(reqs, total, elem_num, metadata, s);
// repeat until we've served all the requests
while (1) {
//double tot_xfer_cost = 0;
double max_op_cost = 0;
int active_parunits = 0;
int op_count = 0;
// do we still have any request to service?
for (i = 0; i < SSD_PARUNITS_PER_ELEM(s); i ++) {
if (ll_get_size(parunits[i]) > 0) {
active_parunits ++;
}
}
// no more requests -- get out
if (active_parunits == 0) {
break;
}
// clear this arrays for storing costs
memset(parunit_op_cost, 0, sizeof(double)*SSD_MAX_PARUNITS_PER_ELEM);
// begin a round of serving. we serve one request per
// parallel unit. if an unit has more than one request
// in the list, they have to be serialized.
max_cost = 0;
for (i = 0; i < SSD_PARUNITS_PER_ELEM(s); i ++) {
int size;
size = ll_get_size(parunits[i]);
if (size > 0) {
// this parallel unit has a request to serve
ssd_req *r;
listnode *n = ll_get_nth_node(parunits[i], 0);
op_count ++;
ASSERT(op_count <= active_parunits);
// get the request
r = (ssd_req *)n->data;
lpn = ssd_logical_pageno(r->blk, s);
if (r->is_read) {
parunit_op_cost[i] = s->params.page_read_latency;
} else {
int plane_num = r->plane_num;
// if this is the last page on the block, allocate a new block
if (ssd_last_page_in_block(metadata->plane_meta[plane_num].active_page, s)) {
_ssd_alloc_active_block(plane_num, elem_num, s);
}
// issue the write to the current active page.
// we need to transfer the data across the serial pins for write.
metadata->active_page = metadata->plane_meta[plane_num].active_page;
//printf("elem %d plane %d ", elem_num, plane_num);
parunit_op_cost[i] = _ssd_write_page_osr(s, metadata, lpn);
}
ASSERT(r->count <= s->params.page_size);
// calc the cost: the access time should be something like this
// for read
if (read_cycle) {
if (SSD_PARUNITS_PER_ELEM(s) > 4) {
printf("modify acc time here ...\n");
ASSERT(0);
}
if (op_count == 1) {
r->acctime = parunit_op_cost[i] + ssd_data_transfer_cost(s,s->params.page_size);
r->schtime = parunit_tot_cost[i] + (op_count-1)*ssd_data_transfer_cost(s,s->params.page_size) + r->acctime;
} else {
r->acctime = ssd_data_transfer_cost(s,s->params.page_size);
r->schtime = parunit_tot_cost[i] + op_count*ssd_data_transfer_cost(s,s->params.page_size) + parunit_op_cost[i];
}
} else {
// for write
r->acctime = parunit_op_cost[i] + ssd_data_transfer_cost(s,s->params.page_size);
r->schtime = parunit_tot_cost[i] + (op_count-1)*ssd_data_transfer_cost(s,s->params.page_size) + r->acctime;
}
// find the maximum cost for this round of operations
if (max_cost < r->schtime) {
max_cost = r->schtime;
}
// release the node from the linked list
ll_release_node(parunits[i], n);
}
}
// we can start the next round of operations only after all
// the operations in the first round are over because we're
// limited by the one set of pins to all the parunits
for (i = 0; i < SSD_PARUNITS_PER_ELEM(s); i ++) {
parunit_tot_cost[i] = max_cost;
}
}
for (i = 0; i < SSD_PARUNITS_PER_ELEM(s); i ++) {
ll_release(parunits[i]);
}
free(parunits);
return max_cost;
}
double ssd_fullmerge(ssd_t *s, ssd_element_metadata *metadata, ssd_power_element_stat *power_stat, int lbn, int elem_num)
{
int prev_block = metadata->lba_table[lbn];
int log_index = metadata->block_usage[prev_block].log_index;
int log_block = metadata->log_data[log_index].bsn;
int num_valid = 0;
int num_valid_d = metadata->block_usage[prev_block].num_valid;
int num_valid_u = metadata->block_usage[log_block].num_valid;
int prev_plane_num = metadata->block_usage[prev_block].plane_num;
int log_plane_num = metadata->block_usage[log_block].plane_num;
int plane_num;
int active_block;
int i;
double cost = 0.0;
double r_cost, w_cost, xfer_cost;
//set active_block
metadata->active_block = metadata->plane_meta[prev_plane_num].active_block;
active_block = metadata->active_block;
_ssd_alloc_active_block(prev_plane_num, elem_num, s);
plane_num = metadata->block_usage[active_block].plane_num;
metadata->plane_meta[prev_plane_num].clean_in_block = prev_block;
metadata->plane_meta[prev_plane_num].clean_in_progress = 1;
metadata->plane_meta[log_plane_num].clean_in_block = prev_block;
metadata->plane_meta[log_plane_num].clean_in_progress = 1;
//page state copy & init page state
for( i = 0 ; i < s->params.pages_per_block ; i++) {
if((metadata->block_usage[prev_block].page[i] == 1) || (metadata->log_data[log_index].page[i] != -1)){
metadata->block_usage[active_block].page[i] = 1;
}
metadata->block_usage[prev_block].page[i] = -1;
metadata->log_data[log_index].page[i] = -1;
metadata->block_usage[log_block].page[i] = -1;
}
metadata->lba_table[lbn] = active_block;
//update stat
//update log_table
metadata->block_usage[prev_block].log_index = -1;
metadata->log_data[log_index].bsn = -1;
metadata->log_data[log_index].data_block = -1;
metadata->log_pos = log_index;
metadata->num_log--;
//update block usage
metadata->block_usage[prev_block].num_valid = 0;
metadata->block_usage[log_block].num_valid = 0;
//update plane data
metadata->plane_meta[prev_plane_num].valid_pages -= num_valid_d;
metadata->plane_meta[log_plane_num].valid_pages -= num_valid_u;
num_valid += num_valid_d;
num_valid += num_valid_u;
if(num_valid > s->params.pages_per_block) {
fprintf(outputfile3, "Error number of pages : valid_page %d, Real_page %d\n", num_valid, s->params.pages_per_block);
fprintf(outputfile3, "Error elem_num %d, lbn %d, original block %d, log block %d\n", elem_num, lbn, prev_block, log_block);
exit(-1);
}
metadata->block_usage[active_block].num_valid = num_valid;
metadata->plane_meta[plane_num].valid_pages += num_valid;
//data tranfer cost
//read
r_cost = s->params.page_read_latency * num_valid;
cost += r_cost;
ssd_power_flash_calculate(SSD_POWER_FLASH_READ, r_cost, power_stat, s);
//write
w_cost = s->params.page_write_latency * num_valid;
cost += w_cost;
ssd_power_flash_calculate(SSD_POWER_FLASH_WRITE, w_cost, power_stat, s);
//transfer cost
for( i = 0 ; i < num_valid ; i++) {
double xfer_cost;
xfer_cost = ssd_crossover_cost(s, metadata, power_stat, prev_block, active_block);
cost += xfer_cost;
s->elements[elem_num].stat.tot_xfer_cost += xfer_cost;
}
//erase two block(D)
cost += s->params.block_erase_latency;
ssd_power_flash_calculate(SSD_POWER_FLASH_ERASE, s->params.block_erase_latency, power_stat, s);
ssd_update_free_block_status(prev_block, prev_plane_num, metadata, s);
ssd_update_block_lifetime(simtime+cost, prev_block, metadata);
metadata->plane_meta[prev_plane_num].num_cleans++;
metadata->plane_meta[prev_plane_num].clean_in_block = 0;
metadata->plane_meta[prev_plane_num].clean_in_progress = -1;
//erase two block(U)
cost += s->params.block_erase_latency;
ssd_power_flash_calculate(SSD_POWER_FLASH_ERASE, s->params.block_erase_latency, power_stat, s);
ssd_update_free_block_status(log_block, log_plane_num, metadata, s);
ssd_update_block_lifetime(simtime+cost, log_block, metadata);
metadata->plane_meta[log_plane_num].num_cleans++;
metadata->plane_meta[log_plane_num].clean_in_block = 0;
metadata->plane_meta[log_plane_num].clean_in_progress = -1;
//erase stat update
s->elements[elem_num].stat.pages_moved += num_valid;
s->elements[elem_num].stat.num_clean += 2;
s->elements[elem_num].stat.num_fullmerge++;
return cost;
}
double ssd_replacement(ssd_t *s, int elem_num, int lbn)
{
ssd_element_metadata *metadata;
ssd_power_element_stat *power_stat;
int block;
int log_index;
int prev_log_block;
int prev_plane_num;
int log_block;
int plane_num;
int num_valid;
double cost = 0.0;
double r_cost, w_cost, xfer_cost;
int i,j;
metadata = &(s->elements[elem_num].metadata);
power_stat = &(s->elements[elem_num].power_stat);
block = metadata->lba_table[lbn];
log_index = metadata->block_usage[block].log_index;
prev_log_block = metadata->log_data[log_index].bsn;
prev_plane_num = metadata->block_usage[prev_log_block].plane_num;
num_valid = metadata->block_usage[prev_log_block].num_valid;
//alloc new logblock and erase old logblock
log_block = metadata->plane_meta[prev_plane_num].active_block;
_ssd_alloc_active_block(prev_plane_num, elem_num, s);
plane_num = metadata->block_usage[log_block].plane_num;
metadata->log_data[log_index].bsn = log_block;
//move page old to new
j = 0;
for( i = 0 ; i < s->params.pages_per_block ; i++) {
if( metadata->log_data[log_index].page[i] != -1) {
metadata->log_data[log_index].page[i] = j;
metadata->block_usage[log_block].page[j] = 1;
metadata->block_usage[log_block].num_valid++;
j++;
}
metadata->block_usage[prev_log_block].page[i] = -1;
}
metadata->block_usage[prev_log_block].num_valid = 0;
//plane metadata update
metadata->plane_meta[prev_plane_num].valid_pages -= metadata->block_usage[log_block].num_valid;
metadata->plane_meta[plane_num].valid_pages += metadata->block_usage[log_block].num_valid;
//cost
//read
r_cost = s->params.page_read_latency * num_valid;
cost += r_cost;
ssd_power_flash_calculate(SSD_POWER_FLASH_READ, r_cost, power_stat, s);
//write
w_cost = s->params.page_write_latency * num_valid;
cost += w_cost;
ssd_power_flash_calculate(SSD_POWER_FLASH_WRITE, w_cost, power_stat, s);
//transfer cost
for( i = 0 ; i < num_valid ; i++) {
double xfer_cost;
xfer_cost = ssd_crossover_cost(s, metadata, power_stat, prev_log_block, log_block);
cost += xfer_cost;
s->elements[elem_num].stat.tot_xfer_cost += xfer_cost;
}
//erase U block
cost += s->params.block_erase_latency;
ssd_power_flash_calculate(SSD_POWER_FLASH_ERASE, s->params.block_erase_latency, power_stat, s);
ssd_update_free_block_status(prev_log_block, prev_plane_num, metadata, s);
ssd_update_block_lifetime(simtime+cost, prev_log_block, metadata);
s->elements[elem_num].stat.pages_moved += num_valid;
s->elements[elem_num].stat.num_clean ++;
s->elements[elem_num].stat.num_replacement++;
metadata->plane_meta[prev_plane_num].num_cleans++;
return cost;
}
