On Thursday 26 April 2007 22:07, Ingo Molnar wrote: > * Michael Gerdau <[EMAIL PROTECTED]> wrote: > > Hi list, > > > > find below a test comparing > > 2.6.21-rc7 (mainline) > > 2.6.21-rc7-sd046 > > 2.6.21-rc7-cfs-v6-rc2(*) (X @ nice 0) > > 2.6.21-rc7-cfs-v6-rc2(*) (X @ nice -10) > > running on a dualcore x86_64. > > thanks for the testing!
Very interesting indeed but fairly complicated as well. > as a summary: i think your numbers demonstrate it nicely that the > shorter 'timeslice length' that both CFS and SD utilizes does not have a > measurable negative impact on your workload. To measure the total impact > of 'timeslicing' you might want to try the exact same workload with a > much higher 'timeslice length' of say 400 msecs, via: > > echo 400000000 > /proc/sys/kernel/sched_granularity_ns # on CFS > echo 400 > /proc/sys/kernel/rr_interval # on SD I thought that the effective "timeslice" on CFS was double the sched_granularity_ns so wouldn't this make the effective timeslice double that of what you're setting SD to? Anyway the difference between 400 and 800ms timeslices is unlikely to be significant so I don't mind. -- -ck - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
