[dm-devel] Re: [PATCH 18/18] io-controller: Debug hierarchical IO scheduling

[Vivek Goyal <vgoyal redhat com>]

On Wed, May 06, 2009 at 05:40:43PM -0400, IKEDA, Munehiro wrote:
> Hi Vivek,
> 
> Patching and compilation error occurred on the 18/18 patch.
> I know this is a patch for debug but report them in case.
> 
> 
> Vivek Goyal wrote:
> > @@ -2203,6 +2241,25 @@ EXPORT_SYMBOL(elv_get_slice_idle);
> >  void elv_ioq_served(struct io_queue *ioq, bfq_service_t served)
> >  {
> >  	entity_served(&ioq->entity, served, ioq->nr_sectors);
> 
> Patch failed due to this line.  I guess this should be
> 
> 	entity_served(&ioq->entity, served);
> 
> 
> > +
> > +#ifdef CONFIG_DEBUG_GROUP_IOSCHED
> > +		{
> > +			struct elv_fq_data *efqd = ioq->efqd;
> > +			char path[128];
> > +			struct io_group *iog = ioq_to_io_group(ioq);
> > +			io_group_path(iog, path, sizeof(path));
> > +			elv_log_ioq(efqd, ioq, "ioq served: QSt=0x%lx QSs=0x%lx"
> > +				" QTt=0x%lx QTs=0x%lx grp=%s GTt=0x%lx "
> > +				" GTs=0x%lx rq_queued=%d",
> > +				served, ioq->nr_sectors,
> > +				ioq->entity.total_service,
> > +				ioq->entity.total_sector_service,
> > +				path,
> > +				iog->entity.total_service,
> > +				iog->entity.total_sector_service,
> > +				ioq->nr_queued);
> > +		}
> > +#endif
> >  }
> 
> Because
>   io_entity::total_service
> and
>   io_entity::total_sector_service
> are not defined, compilation failed if CONFIG_DEBUG_GROUP_IOSCHED=y
> here. (and everywhere referencing entity.total_service or  entity.total_sector_service)
> They need to be defined like:
> 
> diff --git a/block/elevator-fq.h b/block/elevator-fq.h
> index 1ea4ff3..6d0a735 100644
> --- a/block/elevator-fq.h
> +++ b/block/elevator-fq.h
> @@ -147,6 +147,10 @@ struct io_entity {
>         unsigned short ioprio_class, new_ioprio_class;
>  
>         int ioprio_changed;
> +
> +#ifdef CONFIG_DEBUG_GROUP_IOSCHED
> +       unsigned long total_service, total_sector_service;
> +#endif
>  };
>  
>  /*
> 
> Unfortunately I couldn't figure out where and how the members
> should be calculated, sorry.

Hi Ikeda,

I think there is some issue with applying the patch. I think you have
forgotten to apply following patch and that's why seeing all the issues.

"io-controller: Export disk time used and nr sectors dipatched through
cgroups"

This patch changes elv_ioq_served() at the same time introduced additional
field of total_sector_service etc.

Thanks
Vivek