On Mon, Dec 08, 2014 at 02:19:31PM +0100, Cyril Hrubis wrote: > Hi! > > > It tests timer precision for getrusage timers. If the timers are > > > incremting by larger values than expected, something is wrong in kernel. > > > The precision depends on CONFIG_HZ settings which is represented by the > > > BIAS_MAX. > > Where does the 1000 come from? If on a slow system, we need to increase > > the "factor_nr", right? > > The factor is set to 1 and it shouldn't needed to change that. > > > > > And looks like with this patch applied, it works well on powerpc: > > > > > > Can you please share the output of the testcase on ppc and ppc64? What > > > is the expected timer granularity there? > > > > > Looks like the granularity is 10000us: > > > > getrusage04 0 TINFO : Expected timers granularity is 10000 us > > getrusage04 0 TINFO : Using 1 as multiply factor for max [us]time > > increment (1000+10000us)! > > getrusage04 0 TINFO : utime: 56us; stime: 1192us > > getrusage04 0 TINFO : utime: 56us; stime: 2009us > > getrusage04 0 TINFO : utime: 56us; stime: 4233us > > getrusage04 0 TINFO : utime: 1227us; stime: 5243us > > getrusage04 0 TINFO : utime: 1227us; stime: 8541us > > getrusage04 0 TINFO : utime: 2072us; stime: 8741us > > getrusage04 0 TINFO : utime: 2602us; stime: 11169us > > getrusage04 0 TINFO : utime: 2743us; stime: 11747us > > getrusage04 0 TINFO : utime: 2948us; stime: 12790us > > getrusage04 0 TINFO : utime: 2948us; stime: 18118us > > getrusage04 0 TINFO : utime: 2948us; stime: 18596us > > getrusage04 0 TINFO : utime: 4458us; stime: 20030us > > getrusage04 0 TINFO : utime: 4458us; stime: 20244us > > getrusage04 0 TINFO : utime: 4458us; stime: 23432us > > getrusage04 0 TINFO : utime: 5412us; stime: 24650us > > getrusage04 0 TINFO : utime: 5412us; stime: 27273us > > getrusage04 0 TINFO : utime: 6125us; stime: 27909us > > getrusage04 0 TINFO : utime: 6125us; stime: 27911us > > getrusage04 0 TINFO : utime: 6125us; stime: 28111us > > getrusage04 0 TINFO : utime: 6235us; stime: 28513us > > getrusage04 0 TINFO : utime: 6235us; stime: 28750us > > getrusage04 1 TPASS : Test Passed > > Hmm, this looks like the granularity of the timer is much smaller than > 10000us and it varies greatly between measurements. Is this CONFIG_NO_HZ > system?
Yes, looks like it is: % grep CONFIG_NO_HZ /boot/config-2.6.32-504.el6.ppc64 CONFIG_NO_HZ=y ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=164703151&iu=/4140/ostg.clktrk _______________________________________________ Ltp-list mailing list Ltp-list@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ltp-list
