Commit ba48a33e authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim

f2fs: in prior to issue big discard

Keep issuing big size discard in prior instead of the one with random
size, so that we expect that it will help to:
- be quick to recycle unused large space in flash storage device.
- give a chance for
  a) wait to merge small piece discards into bigger one, or
  b) avoid issuing discards while they have being reallocated by SSR.
Signed-off-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 46f84c2c
......@@ -188,6 +188,11 @@ struct discard_entry {
unsigned char discard_map[SIT_VBLOCK_MAP_SIZE]; /* segment discard bitmap */
};
/* max discard pend list number */
#define MAX_PLIST_NUM 512
#define plist_idx(blk_num) ((blk_num) >= MAX_PLIST_NUM ? \
(MAX_PLIST_NUM - 1) : (blk_num - 1))
enum {
D_PREP,
D_SUBMIT,
......@@ -221,7 +226,7 @@ struct discard_cmd {
struct discard_cmd_control {
struct task_struct *f2fs_issue_discard; /* discard thread */
struct list_head entry_list; /* 4KB discard entry list */
struct list_head pend_list; /* store pending entries */
struct list_head pend_list[MAX_PLIST_NUM];/* store pending entries */
struct list_head wait_list; /* store on-flushing entries */
wait_queue_head_t discard_wait_queue; /* waiting queue for wake-up */
struct mutex cmd_lock;
......
......@@ -677,9 +677,13 @@ static struct discard_cmd *__create_discard_cmd(struct f2fs_sb_info *sbi,
block_t start, block_t len)
{
struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
struct list_head *pend_list = &(dcc->pend_list);
struct list_head *pend_list;
struct discard_cmd *dc;
f2fs_bug_on(sbi, !len);
pend_list = &dcc->pend_list[plist_idx(len)];
dc = f2fs_kmem_cache_alloc(discard_cmd_slab, GFP_NOFS);
INIT_LIST_HEAD(&dc->list);
dc->bdev = bdev;
......@@ -806,9 +810,16 @@ static struct discard_cmd *__insert_discard_tree(struct f2fs_sb_info *sbi,
return dc;
}
static void __relocate_discard_cmd(struct discard_cmd_control *dcc,
struct discard_cmd *dc)
{
list_move_tail(&dc->list, &dcc->pend_list[plist_idx(dc->len)]);
}
static void __punch_discard_cmd(struct f2fs_sb_info *sbi,
struct discard_cmd *dc, block_t blkaddr)
{
struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
struct discard_info di = dc->di;
bool modified = false;
......@@ -819,6 +830,7 @@ static void __punch_discard_cmd(struct f2fs_sb_info *sbi,
if (blkaddr > di.lstart) {
dc->len = blkaddr - dc->lstart;
__relocate_discard_cmd(dcc, dc);
modified = true;
}
......@@ -832,6 +844,7 @@ static void __punch_discard_cmd(struct f2fs_sb_info *sbi,
dc->lstart++;
dc->len--;
dc->start++;
__relocate_discard_cmd(dcc, dc);
}
}
}
......@@ -890,6 +903,7 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi,
prev_dc->bdev == bdev &&
__is_discard_back_mergeable(&di, &prev_dc->di)) {
prev_dc->di.len += di.len;
__relocate_discard_cmd(dcc, prev_dc);
di = prev_dc->di;
tdc = prev_dc;
merged = true;
......@@ -901,6 +915,7 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi,
next_dc->di.lstart = di.lstart;
next_dc->di.len += di.len;
next_dc->di.start = di.start;
__relocate_discard_cmd(dcc, next_dc);
if (tdc)
__remove_discard_cmd(sbi, tdc);
......@@ -961,16 +976,20 @@ void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
void f2fs_wait_discard_bios(struct f2fs_sb_info *sbi)
{
struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
struct list_head *pend_list = &(dcc->pend_list);
struct list_head *pend_list;
struct list_head *wait_list = &(dcc->wait_list);
struct discard_cmd *dc, *tmp;
struct blk_plug plug;
int i;
mutex_lock(&dcc->cmd_lock);
blk_start_plug(&plug);
list_for_each_entry_safe(dc, tmp, pend_list, list)
__submit_discard_cmd(sbi, dc);
for (i = 0; i < MAX_PLIST_NUM; i++) {
pend_list = &dcc->pend_list[i];
list_for_each_entry_safe(dc, tmp, pend_list, list)
__submit_discard_cmd(sbi, dc);
}
blk_finish_plug(&plug);
list_for_each_entry_safe(dc, tmp, wait_list, list) {
......@@ -986,26 +1005,30 @@ static int issue_discard_thread(void *data)
struct f2fs_sb_info *sbi = data;
struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
wait_queue_head_t *q = &dcc->discard_wait_queue;
struct list_head *pend_list = &dcc->pend_list;
struct list_head *pend_list;
struct list_head *wait_list = &dcc->wait_list;
struct discard_cmd *dc, *tmp;
struct blk_plug plug;
int iter = 0;
int iter = 0, i;
repeat:
if (kthread_should_stop())
return 0;
mutex_lock(&dcc->cmd_lock);
blk_start_plug(&plug);
list_for_each_entry_safe(dc, tmp, pend_list, list) {
f2fs_bug_on(sbi, dc->state != D_PREP);
for (i = MAX_PLIST_NUM - 1; i >= 0; i--) {
pend_list = &dcc->pend_list[i];
list_for_each_entry_safe(dc, tmp, pend_list, list) {
f2fs_bug_on(sbi, dc->state != D_PREP);
if (is_idle(sbi))
__submit_discard_cmd(sbi, dc);
if (is_idle(sbi))
__submit_discard_cmd(sbi, dc);
if (iter++ > DISCARD_ISSUE_RATE)
break;
if (iter++ > DISCARD_ISSUE_RATE)
goto next_step;
}
}
next_step:
blk_finish_plug(&plug);
list_for_each_entry_safe(dc, tmp, wait_list, list) {
......@@ -1020,7 +1043,7 @@ static int issue_discard_thread(void *data)
congestion_wait(BLK_RW_SYNC, HZ/50);
wait_event_interruptible(*q, kthread_should_stop() ||
!list_empty(pend_list) || !list_empty(wait_list));
atomic_read(&dcc->discard_cmd_cnt));
goto repeat;
}
......@@ -1300,7 +1323,7 @@ static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
{
dev_t dev = sbi->sb->s_bdev->bd_dev;
struct discard_cmd_control *dcc;
int err = 0;
int err = 0, i;
if (SM_I(sbi)->dcc_info) {
dcc = SM_I(sbi)->dcc_info;
......@@ -1312,7 +1335,8 @@ static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
return -ENOMEM;
INIT_LIST_HEAD(&dcc->entry_list);
INIT_LIST_HEAD(&dcc->pend_list);
for (i = 0; i < MAX_PLIST_NUM; i++)
INIT_LIST_HEAD(&dcc->pend_list[i]);
INIT_LIST_HEAD(&dcc->wait_list);
mutex_init(&dcc->cmd_lock);
atomic_set(&dcc->issued_discard, 0);
......
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