Re: [tbench regression fixes]: digging out smelly deadmen.

Evgeniy Polyakov
2008-10-10T08:09:28Z

Hi Peter.

I've enabled kernel hacking option and scheduler debugging and turned
off hrticks and performance jumped to 382 MB/s:

vanilla 27: 347.222
no TSO/GSO: 357.331
no hrticks: 382.983

I use tsc clocksource, also available acpi_pm and jiffies,
with acpi_pm performance is even lower (I stopped test after it dropped
below 340 MB/s mark), jiffies do not work at all, looks like sockets
stuck in time_wait state when this clock source is used, although that
may be some different issue.

So I think hrticks are guilty, but still not as good as .25 tree without
mentioned changes (455 MB/s) and .24 (475 MB/s).

--
Evgeniy Polyakov