[dm-devel] [PATCH] block: flush queued bios when the process blocks

Jens Axboe axboe at kernel.dk
Tue May 27 15:08:41 UTC 2014

On 2014-05-27 09:03, Mikulas Patocka wrote:
> The block layer uses per-process bio list to avoid recursion in
> generic_make_request. When generic_make_request is called recursively, the
> bio is added to current->bio_list and the function returns immediatelly.
> The top-level instance of generic_make_requests takes bios from
> current->bio_list and processes them.

This really begs the question of why we just don't use the per-process 
plugs for this. We already have scheduler hooks in place to flush those 
at the appropriate time. Why are we reinventing something for 
essentially the same thing?

Jens Axboe

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