Re: MMC quirks relating to performance/lifetime.

Arnd Bergmann
2011-02-22T16:49:22Z

On Tuesday 22 February 2011, Andrei Warkentin wrote:
> On Sun, Feb 20, 2011 at 9:23 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> > The description of the test case is probably suboptimal. What this does
> > is 32 KB accesses, with 32 KB alignment in the pre and post case, but 16 KB
> > alignment in the "on" case. The idea here is that it should never do
> > any access with less than "--blocksize" aligment.
> >
>
> Now I feel slightly confused :(.
>
> -b 16384 implies blocksize = 16384, maxalign is 8mb due to count 32,
>
> ret = time_rw_interval(dev, count, pre, blocksize,
> align - blocksize, maxalign,
> do_write); //
> <----------------- read 16k at align - 16k with 8mb intervals?
> returnif(ret);
>
> ret = time_rw_interval(dev, count, on, blocksize,
> align - blocksize / 2, maxalign,
> do_write); //
> <----------------- read 16k at align - 8k with 8mb intervals?
> returnif(ret);
>
> ret = time_rw_interval(dev, count, post, blocksize,
> align, maxalign, do_write); //
> <-------- read 16k at align with 8mb intervals?
> returnif(ret);
>
> I hope I'm not missing something obvious...

No, you are absolutely right. I think I changed this once and no longer
remembered what the final version did.

Arnd