Re: 4.4-final: 28 bioset threads on small notebook

[Kent Overstreet]

On Sun, Feb 21, 2016 at 05:40:59PM +0800, Ming Lei wrote:
> On Sun, Feb 21, 2016 at 2:43 PM, Ming Lin-SSI <ming.l@xxxxxxxxxxxxxxx> wrote:
> >>-----Original Message-----
> >
> > So it's almost already "per request_queue"
> 
> Yes, that is because of the following line:
> 
> q->bio_split = bioset_create(BIO_POOL_SIZE, 0);
> 
> in blk_alloc_queue_node().
> 
> Looks like this bio_set doesn't need to be per-request_queue, and
> now it is only used for fast-cloning bio for splitting, and one global
> split bio_set should be enough.

It does have to be per request queue for stacking block devices (which includes
loopback).