Re: [PATCH] UBI: Add volume read and write statistics

[Richard Weinberger <richard@nod.at>]

Per,

Am Dienstag, 17. Juli 2018, 14:08:51 CEST schrieb Per Förlin:
> > To: Per Förlin
> > Cc: linux-mtd@lists.infradead.org; Artem Bityutskiy; Per Förlin
> > Subject: Re: [PATCH] UBI: Add volume read and write statistics
> > 
> > Am Dienstag, 17. Juli 2018, 12:30:19 CEST schrieb Per Forlin:
> > > Simple read and write statistics.
> > > * Bytes read
> > > * Bytes written
> > > * Number of reads
> > > * Number of writes
> > >
> > > This is useful to find out how the storage is being utilized.
> > > For block devices this already exists via /proc/diskstats.
> > > The intention of this patch is to add similar stats
> > > for UBI as well.
> > 
> > Why on UBI level and not MTD?
> In my case I wanted to evaluate the performance per volume. I have one MTD
> device with several UBI volumes. It would be sufficient to have it on
> an MTD level to see the overall storage usage.
> This would still be very helpful for me.
> 
> Having it on an MTD level is of course more general.
> I wouldn't mind changing the patch to add the stats in mtdcore
> for mtd_read() and mtd_write()
> 
> In case of MTD block devices the stats will be somewhat redundant with
> /proc/diskstats.
> 
> Do you think I should update the patch to add MTD stats instead?

While having a cup of coffee I thought more about this.
Actually both, MTD and UBI makes sense.
The most important issue is that you integrate it with the existing diskstats.
So instead of having our own interface feeding MTD/UBI stats into diskstats
would be nice. Did you look into that? I'm not sure how much work this would be.
That way users can use existing tools such as iostat...

Thanks,
//richard