Re: [PATCH 0/7] blk-mq: fix queue quiescing

Jens Axboe
2017-05-25T17:31:30Z

On 05/25/2017 11:24 AM, Bart Van Assche wrote:
> On Thu, 2017-05-25 at 17:09 +0800, Ming Lei wrote:
>> Another big issue is that 'srcu_struct' is very big, which shouldn't
>> be embedded into hctx, since we only have one real user of
>> BLK_MQ_F_BLOCKING.
>>
>> So I will fix that too.
>
> Hello Ming,
>
> Is something like the (untested) patch below perhaps what you had in mind?
>
> Subject: [PATCH] blk-mq: Reduce blk_mq_hw_ctx size
>
> Since the srcu structure is rather large (184 bytes on an x86-64
> system), only allocate it if needed.

On my normal laptop setup, it's actually 408 bytes (!!).

--
Jens Axboe