Re: [PATCH -next V5] blk-mq: fix tag_get wait task can't be awakened

From: Jens Axboe
Date: Thu Jan 13 2022 - 14:52:40 EST


On Thu, 13 Jan 2022 10:55:36 +0800, Laibin Qiu wrote:
> In case of shared tags, there might be more than one hctx which
> allocates from the same tags, and each hctx is limited to allocate at
> most:
> hctx_max_depth = max((bt->sb.depth + users - 1) / users, 4U);
>
> tag idle detection is lazy, and may be delayed for 30sec, so there
> could be just one real active hctx(queue) but all others are actually
> idle and still accounted as active because of the lazy idle detection.
> Then if wake_batch is > hctx_max_depth, driver tag allocation may wait
> forever on this real active hctx.
>
> [...]

Applied, thanks!

[1/1] blk-mq: fix tag_get wait task can't be awakened
commit: 180dccb0dba4f5e84a4a70c1be1d34cbb6528b32

Best regards,
--
Jens Axboe