> > On Thu, 2016-01-14 at 12:07 -0500, Frediano Ziglio wrote: > > > > > > On Thu, Jan 14, 2016 at 10:27:02AM -0500, Frediano Ziglio wrote: > > > > Had a small discussion with Pavel. > > > > We agree that original code is quite complicated and is hard to > > > > understand > > > > the final compression format used. > > > > > > > > So we would like to have some public discussion about the topic. > > > > > > > > I personally agree we should have a single code deciding the > > > > compression > > > > to use. > > > > > > I definitely agree here. For one, having different compression being > > > used depending on whether the qxl driver is used or not is unexpected > > > (eg if you set image compression to glz, lz will still be used during > > > initial bootup, and then will 'switch' to glz later on. I haven't looked > > > at the code, so there might be good reasons for that). > > > > > > > > > > > This is the list of actual compressions: > > > > - AUTO_GLZ; > > > > - AUTO_LZ; > > > > - QUIC; > > > > - GLZ; > > > > - LZ; > > > > - LZ4. > > > > A client can also decide to disable compression. > > > > > > > > The AUTO_XXX looks like they should use QUIC as a fallback if XXX is > > > > not > > > > possible or if an image with high graduality is detected. > > > > > > (side question, do we have numbers on compression ratio and cpu usage > > > for quic/lz/glz/lz4?) > > > > > > > Brief and raw of a Windows replay capture > > > > Images MB before MB after Ratio CPU time > > LZ4 193 24.21 2.43 10.04% 0.04 > > QUIC 204 23.11 1.66 7.18% 0.44 > > GLZ 190 20.05 1.2 5.99% 0.14 > > LZ 202 20.42 2.04 9.99% 0.15 > > > > So why use Quic ? > > Interesting data. Indeed, QUIC seems to be the worst choice. from this data, > it > seems that you'd want GLZ if you were optimizing for network bandwidth, and > LZ4 > if you're optimizing for CPU usage. Might be nice to see data for a slightly > larger sample as well. > > Out of curiosity, did you write a little utility for doing this benchmark, or > did you just modify the code in-place?? Having a little benchmark utility > that > you could run on different replay captures might be a useful thing to have in > the repository... > > Jonathon > > No code modification at all. Compile with COMPRESS_STAT enabled, run replay utility with SPICE_DEBUG_LEVEL=3 set at the end you see a similar table (I added just ratio with LibreOffice calc). Oh... you just need to use -C replay option with - 4 quic - 5 glz - 6 lz - 7 lz4 (not sure about 5/6, maybe swapped). I think would be really helpful to collect different replay captures of normal day job. Frediano _______________________________________________ Spice-devel mailing list Spice-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/spice-devel