Stefan Lambrev wrote:
Hi,
Dag-Erling Smørgrav wrote:
Stefan Lambrev <[EMAIL PROTECTED]> writes:
I tested all different combination. The performance change is almost
invisible (100-200KB/s), and can't be compared with the performance
boost that TSC gain over ACPI-fast timecounter. Unfortunately TSC
doesn't play nice with power saving modes.
This will vary greatly from machine to machine, depending on the exact
hardware and the ACPI BIOS.
More modern machines have an HPET timer which is supposedly faster than
ACPI yet more reliable than TSC.
DES
I do not have HEPT on the servers that I test, but simple test on my
laptop shows
that hping can generate with ACPI-fast ~4MB/s traffic, 5MB/s with HPET
and 8MB/s with TSC. I didn't check dummy time counter.
Also I noticed that there is a kern.timecounter.tc.XXX.quality (read only).
Can this be used to reduce quality and speed up performance?
No, they are meaningless values only used to rank the time counters and
choose one at boot.
You should use hwpmc to verify where the application is really spending
time, since gettimeofday doesn't seem to account for it all.
Kris
_______________________________________________
freebsd-hackers@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-hackers
To unsubscribe, send any mail to "[EMAIL PROTECTED]"
