Re: [PATCH-next v3] lib: parser: optimize match_NUMER apis to use local array

From: Tejun Heo
Date: Thu Jan 19 2023 - 21:00:19 EST


On Fri, Jan 20, 2023 at 10:13:04AM +0800, Li Lingfeng wrote:
> Memory will be allocated to store substring_t in match_strdup(), which means
> the caller of match_strdup() may need to be scheduled out to wait for reclaiming
> memory.
>
> Using local array to store substring_t to remove the restriction.
>
> Link: https://lore.kernel.org/all/20221104023938.2346986-5-yukuai1@xxxxxxxxxxxxxxx/
> Signed-off-by: Li Lingfeng <lilingfeng3@xxxxxxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

This fixes a sleep-while-atomic splat in blk-iocost, so it'd be a good idea to add:

Fixes: 2c0647988433 ("blk-iocost: don't release 'ioc->lock' while updating params").

The mm tree likely is the best fit but given the splat the block tree can
work too. Andrew, Jens, what do you think?

Thanks.

--
tejun