Re: [PATCH v2 0/8] zram: switch to crypto api

[Sergey Senozhatsky]

On (05/31/16 12:07), Andrew Morton wrote:
> > test-fio-zram-842
> >      197.907655282 seconds time elapsed
> >      201.623142884 seconds time elapsed
> >      226.854291345 seconds time elapsed
> > test-fio-zram-DEFLATE
> >      253.259516155 seconds time elapsed
> >      258.148563401 seconds time elapsed
> >      290.251909365 seconds time elapsed
> > test-fio-zram-LZ4
> >       27.022598717 seconds time elapsed
> >       29.580522717 seconds time elapsed
> >       33.293463430 seconds time elapsed
> > test-fio-zram-LZ4HC
> >       56.393954615 seconds time elapsed
> >       74.904659747 seconds time elapsed
> >      101.940998564 seconds time elapsed
> > test-fio-zram-LZO
> >       28.155948075 seconds time elapsed
> >       30.390036330 seconds time elapsed
> >       34.455773159 seconds time elapsed
> 
> I'm having trouble understanding the benchmark results.  What is being
> compared to what and which was faster and how much?

Hello,

'benchmarking' was probably a bit too strong word to use here. basically,
I performed fio test with the increasing number of parallel jobs (max to 3)
on a 3G zram device, using `static' data and the following crypto comp
algorithms:
	842, deflate, lz4, lz4hc, lzo

the output was:
 - test running time (which can tell us what algorithms performs faster)
and
 - zram mm_stat (which tells the compressed memory size, max used memory, etc).

it's just for information. for example, LZ4HC has twice the running time
of LZO, but the compressed memory size is: 23592960 vs 34603008 bytes.

	-ss