Re: [patch]btrfs: finish read pages in the order they are submitted

[Jens Axboe <jens.axboe@oracle.com>]

On Mon, Feb 08 2010, Jens Axboe wrote:
> Cache stats (millions)
> 
> Kernel          References              Misses
> ----------------------------------------------
> baseline        3547                    2387
> patched         3822                    2351
> 
> These numbers are very stable, the above were also averaged over 3 runs,
> but variability was very low.

Update on this. I setup the storage system for more stable runs and
repeated the above test. It runs a bit faster as well, completes the
workload at 2.5GB/sec average.

Cache stats (millions)

Kernel          References              Misses
----------------------------------------------
baseline        3384                    2318
baseline        3417                    2313
baseline        3382                    2323
baseline avg    3394                    2318

patched         3518                    2258
patched         3428                    2201
patched         3536                    2274
patched avg     3494                    2244

So for those runs, ~3% more references and ~3 less misses. Even with the
variability here, that looks like a win in my book.

-- 
Jens Axboe