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Opened 5 years ago

Closed 5 years ago

#181 closed task (worksforme)

to yield or not to yield

Reported by: Antoine Martin Owned by: Antoine Martin
Priority: trivial Milestone: 0.8
Component: core Version: trunk
Keywords: Cc:

Description

r1365 introduced the XPRA_YIELD environment variable to toggle thread yielding in both network threads (protocol.py) and encoding thread (server_source.py).

Which means we now have graphs comparing with/without yield (also split between each type of yield) here:
https://www.xpra.org/stats/YIELD-vs-NOYIELD/

Notes:

  • each page has two sets of graphs: there is no download limit in the top half and (128-KB/s-down, 32-KB/s-up, 100ms-latency) in the bottom half
  • gtkperf is problematic throughout.. (beware when looking at specific graphs: in some cases it performed very badly, which means other measures like latency will actually look good!)
  • deluxe and polytopes benefit a lot from yielding with download limits
  • the client latency has some conflicting results, 'eruption' is much worse with yielding but most other tests are either unchanged or much improved ('polytopes', 'rss-glx*')
  • the number of packets sent is the same or higher when yielding
  • we manage to send more pixels/s, although it seems that in a number of cases only one type of yielding is beneficial and having both negates the gains (and in a few cases, actually perform worse!)
  • apart from 'polytopes' and 'eruption', when it comes to regions/s, the yielding in the network code is the big winner

And so, the conclusion is... to leave it as it is for now and run more tests once a few other performance/latency issues are resolved.

Change History (2)

comment:1 Changed 5 years ago by Antoine Martin

Milestone: 0.60.8
Status: newaccepted

Review with 0.7 release:

  • we have more threads on the client with the new decoding thread, maybe we need to yield more?
  • latency is now much better - maybe this will have more/less of an impact?

comment:2 Changed 5 years ago by Antoine Martin

Resolution: worksforme
Status: acceptedclosed

We may revisit things later, but this seems to work ok for now.

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