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f2fs: detect congestion of flush command issues

If flush commands do not incur any congestion, we don't need to throw that to
dispatching queue which causes unnecessary latency.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
hifive-unleashed-5.1
Jaegeuk Kim 2016-05-23 12:04:56 -07:00
parent 6d94c74ab8
commit 0a87f664d1
2 changed files with 7 additions and 1 deletions

View File

@ -603,6 +603,7 @@ struct flush_cmd {
struct flush_cmd_control {
struct task_struct *f2fs_issue_flush; /* flush thread */
wait_queue_head_t flush_wait_queue; /* waiting queue for wake-up */
atomic_t submit_flush; /* # of issued flushes */
struct llist_head issue_list; /* list for command issue */
struct llist_node *dispatch_list; /* list for command dispatch */
};

View File

@ -433,24 +433,28 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi)
if (test_opt(sbi, NOBARRIER))
return 0;
if (!test_opt(sbi, FLUSH_MERGE)) {
if (!test_opt(sbi, FLUSH_MERGE) || !atomic_read(&fcc->submit_flush)) {
struct bio *bio = f2fs_bio_alloc(0);
int ret;
atomic_inc(&fcc->submit_flush);
bio->bi_bdev = sbi->sb->s_bdev;
ret = submit_bio_wait(WRITE_FLUSH, bio);
atomic_dec(&fcc->submit_flush);
bio_put(bio);
return ret;
}
init_completion(&cmd.wait);
atomic_inc(&fcc->submit_flush);
llist_add(&cmd.llnode, &fcc->issue_list);
if (!fcc->dispatch_list)
wake_up(&fcc->flush_wait_queue);
wait_for_completion(&cmd.wait);
atomic_dec(&fcc->submit_flush);
return cmd.ret;
}
@ -464,6 +468,7 @@ int create_flush_cmd_control(struct f2fs_sb_info *sbi)
fcc = kzalloc(sizeof(struct flush_cmd_control), GFP_KERNEL);
if (!fcc)
return -ENOMEM;
atomic_set(&fcc->submit_flush, 0);
init_waitqueue_head(&fcc->flush_wait_queue);
init_llist_head(&fcc->issue_list);
SM_I(sbi)->cmd_control_info = fcc;