From: Sahitya Tummala <stummala@xxxxxxxxxxxxxx> [ Upstream commit 56659ce838456c6f2315ce8a4bd686ac4b23e9d1 ] The discard thread should issue upto dpolicy->max_requests at once and wait for all those discard requests at once it reaches dpolicy->max_requests. It should then sleep for dpolicy->min_interval timeout before issuing the next batch of discard requests. But in the current code of is_idle(), it checks for dcc_info->queued_discard and aborts issuing the discard batch of max_requests. This dcc_info->queued_discard will be true always once one discard command is issued. It is thus resulting into this type of discard request pattern - - Issue discard request#1 - is_idle() returns false, discard thread waits for request#1 and then sleeps for min_interval 50ms. - Issue discard request#2 - is_idle() returns false, discard thread waits for request#2 and then sleeps for min_interval 50ms. - and so on for all other discard requests, assuming f2fs is idle w.r.t other conditions. With this fix, the pattern will look like this - - Issue discard request#1 - Issue discard request#2 and so on upto max_requests of 8 - Issue discard request#8 - wait for min_interval 50ms. Signed-off-by: Sahitya Tummala <stummala@xxxxxxxxxxxxxx> Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/f2fs/f2fs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 9e6721e15b24..cbdc2f88a98c 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -2204,7 +2204,7 @@ static inline bool is_idle(struct f2fs_sb_info *sbi, int type) get_pages(sbi, F2FS_DIO_WRITE)) return false; - if (SM_I(sbi) && SM_I(sbi)->dcc_info && + if (type != DISCARD_TIME && SM_I(sbi) && SM_I(sbi)->dcc_info && atomic_read(&SM_I(sbi)->dcc_info->queued_discard)) return false; -- 2.20.1
