Bug 5423 - performance issue with our libjpeg
Summary: performance issue with our libjpeg
Alias: None
Product: ThinLinc
Classification: Unclassified
Component: Build system (show other bugs)
Version: pre-1.0
Hardware: PC Unknown
: P2 Normal
Target Milestone: 4.4.0
Assignee: Pierre Ossman
Keywords: hean01_tester, relnotes
Depends on:
Reported: 2015-02-05 14:28 CET by Pierre Ossman
Modified: 2015-05-06 14:32 CEST (History)
2 users (show)

See Also:
Acceptance Criteria:


Description Pierre Ossman cendio 2015-02-05 14:28:23 CET
Whilst investigating bug 5242 I discovered that there is a performance issue with our libjpeg compared to Fedora 21's.

Decoding the file googleearth-rgb-24.rfb takes 1.45 seconds with a static build, and 1.04 with a dynamic build (i.e. using Fedora's libraries). gprof on the static build shows that almost all the time is spent inside libjpeg, so I doubt it's one of the other libraries that affects things.
Comment 1 Pierre Ossman cendio 2015-02-05 16:35:05 CET
Apparently we weren't building libjpeg with -O2 which is the cause of the performance difference. Should be easy enough to fix.

I'll be upgrading to 1.4.0 at the same time though as I already tested that to see if it was the version difference that caused problems.
Comment 2 Pierre Ossman cendio 2015-02-05 17:31:37 CET
Fixed by doing bug 4929. Upgrade in r29941 (by accident).
Comment 3 Henrik Andersson cendio 2015-05-06 11:27:33 CEST
I have tried to record a rfb stream using rfbproxy etc. but I have no idea how to continue doing a test as described.

Can the someone write down steps to produce a rfb file and how to decode/playback and measure the performance.
Comment 4 Pierre Ossman cendio 2015-05-06 11:30:55 CEST
Testing during normal usage is sufficient. We don't ship the raw test tools.
Comment 5 Henrik Andersson cendio 2015-05-06 14:32:14 CEST
Verified that building of libjpeg package is using -O2 flag and that the upgrade to 1.4.0 didn't introduced any artifacts or other problems.

I just averaged cpu usage from top with following result:

fc21 - 14.6%
tl build 4746 - 14.6%
tl 4.3.0 - 18.0% 

Which indicates a performance increase. Closing.

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