[Cluster-devel] [GFS2 PATCH 0/5] GFS2: Bitmap search optimizations

[Steven Whitehouse]

Hi,

This looks very good. I'll queue it just as soon as the merge window is
over so that we don't have issues around -next,

Steve.

On Wed, 2013-09-11 at 13:43 -0500, Bob Peterson wrote:
> This set of 5 patches increases the speed of GFS2's bitmap search
> algorithms. To test the performance, I added instrumentation to
> function gfs2_inplace_reserve to report the amount of time spent
> there. With the "stock" gfs2, I got 64586490 microseconds while
> running postmark with 100000 transactions and 100000 files.
> With the patched gfs2, I got 49441435, which is nearly 24% faster.
> Without the 5 GFS2 patches, postmark gave this result:
> 852.13 megabytes written (970.61 kilobytes per second)
> With the 5 patches GFS2, I got:
> 852.13 megabytes written (979.32 kilobytes per second)
> So overall, postmark performance was only 1% faster.
> Using straight dd copying 1MB files, I got 10% faster. Obviously
> mileage will vary: my hardware isn't the fastest.
> 
> The patches are as follows:
> 
> [PATCH 1/5] GFS2: optimize rbm_from_block wrt bi_start
> [PATCH 2/5] GFS2: introduce bi_blocks for optimization
> [PATCH 3/5] GFS2: Introduce rbm field bii
> [PATCH 4/5] GFS2: new function gfs2_rbm_incr
> [PATCH 5/5] GFS2: Do not reset flags on active reservations
> 
> Regards,
> 
> Bob Peterson
> Red Hat File Systems
>