Messages in this thread | | | Date | Mon, 8 Dec 2003 15:54:49 -0800 (PST) | From | markw@osdl ... | Subject | hyperthreading performance with dbt-2 on 2.6.0-test11 |
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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.
For the test with no hyperthreading (http://developer.osdl.org/markw/dbt2-pgsql/258/):
8199701 poll_idle 141374.1552 159442 schedule 93.5144 133488 __copy_from_user_ll 1059.4286 128589 __copy_to_user_ll 1071.5750 73209 DAC960_LP_InterruptHandler 367.8844 51885 __make_request 36.0062 35614 try_to_wake_up 55.6469
For the test with hyperthreading (http://developer.osdl.org/markw/dbt2-pgsql/253/):
20893773 poll_idle 360237.4655 351988 schedule 206.4446 155826 __copy_from_user_ll 1038.8400 152346 __copy_to_user_ll 1269.5500 90983 DAC960_LP_InterruptHandler 457.2010 86936 try_to_wake_up 135.8375 70122 __make_request 48.6620
For the test with hyperthreading and Ingo's patch (http://developer.osdl.org/markw/dbt2-pgsql/260/):
20544823 poll_idle 354221.0862 520575 schedule 231.6756 159609 __copy_from_user_ll 1266.7381 153279 __copy_to_user_ll 1277.3250 139321 try_to_wake_up 221.4960 92447 DAC960_LP_InterruptHandler 464.5578 72162 __make_request 50.0777
-- Mark Wong - - markw@osdl.org Open Source Development Lab Inc - A non-profit corporation 12725 SW Millikan Way - Suite 400 - Beaverton, OR 97005 (503) 626-2455 x 32 (office) (503) 626-2436 (fax) http://developer.osdl.org/markw/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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