On 04/28/2017 08:41 AM, Christoph Hellwig wrote: > On Fri, Apr 28, 2017 at 08:31:49AM -0600, Jens Axboe wrote: >> Instead of bypassing the scheduler for insertion of reserved requests, >> we ensure that the request is marked as RQF_RESERVED so they driver >> knows where it came from. >> >> Usually we just use the tag to know if it's reserved or not, >> but that only works when the request has a driver tag assigned. >> Using RQF_RESERVED can be done independently of whether or not >> scheduling is used. > > Do we really need a flag for this? If anyone cares if a request > is internal it can just check ->tag / ->internal_tag is smaller > than ->nr_reserved_tags using a little helper. > > I'd really like to keep the number of flags down as much as possible.
Ming had the same comment. Once we enter ->queue_rq() and later we don't need the flag, since ->tag has been assigned and the regular helper works fine. We can kill it. I forgot about this in the previous reply, but it was meant to pass the fact that this was a reserved request to get_driver_tag(), but it doesn't need that, since we already use the regular helper against ->internal_tag. I'll drop this patch. -- Jens Axboe
