On Tue, Nov 23, 2021 at 09:18:13AM -0700, Jens Axboe wrote:
> This is essentially never used, yet it's about 1/3rd of the total
> queue size. Allocate it when needed, and don't embed it in the queue.
>
> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
> ---
> block/blk-mq.c | 20 ++++++++++++++++++--
> block/blk-stat.c | 6 ------
> block/blk-sysfs.c | 1 +
> include/linux/blkdev.h | 9 +++++++--
> 4 files changed, 26 insertions(+), 10 deletions(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 20a6445f6a01..cb41c441aa8f 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -4577,9 +4577,25 @@ EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues);
> /* Enable polling stats and return whether they were already enabled. */
> static bool blk_poll_stats_enable(struct request_queue *q)
> {
> - if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) ||
> - blk_queue_flag_test_and_set(QUEUE_FLAG_POLL_STATS, q))
> + struct blk_rq_stat *poll_stat;
> +
> + if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags))
> return true;
Can't we replace the checks for QUEUE_FLAG_POLL_STATS with checks for
q->poll_stat now?
