Hello, I have some data with hyperthreading I wanted to share.
I've seen about a 15% performance decrease in performance on a 4-way
Xeon system when I enable hyperthreading for my DBT-2 workload. I also
gave Ingo's test11-C1 patch that someone pointed me to a try and only
saw a 12% decrease. Has anyone found this to be common with any specific
workloads?
I'm not really sure what to look for, but I do see some changes in the
readprofile data, which I've copied in part below. It appears that the
count of schedule, __make_request, and try_to_wake_up are the only
functions at the top of the profile that are significantly different.
The links I have posted also have pointers to oprofile data as well as
annotated assembly source output, if that interests anyone. If I can
provide any other details, let me know.
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w26p21.gz
Description: Unix tar archive