I tested for a regression using the patched kernel with the nohz=off command line option...
On Mon, Jan 13, 2014 at 10:15:18AM -0800, John Stultz wrote: > On 01/13/2014 09:51 AM, Richard Cochran wrote: > > > > - Linux 3.12.7-nohz-plain-20140106 nohz-plain.log > > - Linux 3.12.7-nohz-plain-20140106 NOHZ=OFF periodic-plain.log > > - Linux 3.12.7-nohz-fix-20140106-00001-gd753140 nohz-fix.log Regression check: - Linux homeboy 3.12.7-nohz-fix-20140106-00001-gd753140 NOHZ=OFF nohz-fix-periodic.log > > The performance in the log files as reflected in the clock offset is > > summarized in this table. The values are in nanoseconds. > > > > | | periodic-plain | nohz-fix | nohz-plain | > > |---------+----------------+---------------+---------------| > > | minimum | -1.599000e+03 | -1.051000e+03 | -5.373700e+04 | > > | maximum | +1.311000e+03 | +1.048000e+03 | +6.389500e+04 | > > | mean | +9.880240e-02 | -7.747305e+01 | +1.597904e+01 | > > | stddev | +4.610021e+02 | +3.960978e+02 | +1.491263e+04 | Comparing the nohz=off case with and without the patch, the three hour test looks like this. | | periodic-plain | nohz-fix-periodic | |---------+----------------+-------------------+ | minimum | -1.599000e+03 | -1.427000e+03 | | maximum | +1.311000e+03 | +1.279000e+03 | | mean | +9.880240e-02 | -2.710778e+01 | | stddev | +4.610021e+02 | +3.974372e+02 | > > http://linuxptp.sourceforge.net/nohz-fix/current_nohz.png > > http://linuxptp.sourceforge.net/nohz-fix/periodic_vs_fix.png I also made a third graph showing before and after the patch. http://linuxptp.sourceforge.net/nohz-fix/nohz_regression.png > If you do get a chance to look again, I'd also be interested if running > with nohz=off w/ the fix doesn't show any regression compared to the > unmodified nohz=off case. Looks like there is no regression. Thanks, Richard -- 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/
