percpu_ida: add an API to return free tags
Add an API to return free tags, blk-mq-tag will use it. Note, this just returns a snapshot of free tags number. blk-mq-tag has two usages of it. One is for info output for diagnosis. The other is to quickly check if there are free tags for request dispatch checking. Neither requires very precise. Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: NShaohua Li <shli@fusionio.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
Showing
想要评论请 注册 或 登录