Re: [PATCH v2] loop: Limit the number of requests in the bio list

[Lukáš Czerner]

On Thu, 8 Nov 2012, Jeff Moyer wrote:

> Date: Thu, 08 Nov 2012 16:53:01 -0500
> From: Jeff Moyer <jmoyer@xxxxxxxxxx>
> To: Lukas Czerner <lczerner@xxxxxxxxxx>
> Cc: axboe@xxxxxxxxx, dchinner@xxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v2] loop: Limit the number of requests in the bio list
> 
> Lukas Czerner <lczerner@xxxxxxxxxx> writes:
> 
> > +	if (lo->lo_bio_count >= lo->lo_queue->nr_requests) {
> > +		unsigned int nr;
> > +		spin_unlock_irq(&lo->lo_lock);
> > +		nr = lo->lo_queue->nr_requests - (lo->lo_queue->nr_requests/8);
> > +		wait_event_interruptible(lo->lo_req_wait,
> > +					 lo->lo_bio_count < nr);
> > +		spin_lock_irq(&lo->lo_lock);
> > +	}
> 
> So, blk_queue_make_request already initialized q->nr_congestion_on and
> q->nr_congestion_off.  Is there a reason you didn't simply use
> queue_congestion_on_threshold and queue_congestion_off_threshold?

The reason is that I did not knew about those :) Thanks for pointing
it out I'll take a look at it.

Thanks!
-Lukas

> 
> Cheers,
> Jeff
> 
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