Kazu Yamamoto
Hi,
Andreas - want me to go ahead and get you some hardware to test Ben's patch in the mean time? This way we'll at least not leave it hanging until the last moment...
I will also try this with two 20-core machines connected 10G on Monday.
I measured the performace of GHC head, 7.8.3 and 7.8.3 + Ben's patch set.
Server: witty 8080 -r -a -s +RTS -N<n> *1 Measurement tool: weighttp -n 100000 -c 1000 -k -t 19 http://192.168.0.1:8080/ Measurement env: two 20 core (w/o HT) machines directly connected 10G
Here is result (req/s):
-N<n> 1 2 4 8 16 --------------------------------------------------------- head 92,855 155,957 306,813 498,613 527,034 7.8.3 86,494 160,321 310,675 494,020 510,751 7.8.3+ben 37,608 69,376 131,686 237,783 333,946
head and 7.8.3 has almost the same performance. But I saw significant performance regression in Ben's patch set.
Hmm, uh oh. Thanks for testing this. I'll try to reproduce this on my end. It looks like it shouldn't be so hard as even the single-threaded performance regresses drastically. Just to confirm, you are using the latest revision of D347? Cheers, - Ben