Jung-uk Kim <j...@freebsd.org> wrote: > On Wednesday 15 June 2011 06:19 pm, Jung-uk Kim wrote: > > On Wednesday 15 June 2011 04:39 pm, Jung-uk Kim wrote: > > > On Wednesday 15 June 2011 03:27 pm, Ian FREISLICH wrote: > > > > > > The problem I noticed first is that it takes unusually long > > > > > > until a key press is repeated. With the default eventtimer > > > > > > (HPET) it seems to take about 4s, which can be slightly > > > > > > improved by switching to i8254. > > > > > > > > > > > > The "error beep" seems to take longer than usual, too, > > > > > > and the system "feels sluggish" in general. > > > > > > > > > > > > An effect that is easier to measure is that the system is > > > > > > unable to properly keep the time. Again the problem is less > > > > > > severe when using i8254 instead of HPET: > > > > > > > > > > [SNIP] > > > > > > > > > > First of all, please do not mix timecounter issues with > > > > > eventtimer. They are not directly related. > > > > > > > > > > Can you please show me verbose boot messages *without* your > > > > > patch? Does "sysctl kern.timecounter.hardware=HPET" help > > > > > *without* touching eventtimers? > > > > > > > > I have the same issue with my system (Atom N270). The effect > > > > that I see is about 29 wall clock seconds are recorded as 1 > > > > system second. > > > > > > Can please you send me output from the following? > > > > > > sh -c 'count=10; while [ $count -gt 0 ]; do count=$((count - > > > 1));\ sysctl kern.timecounter; sleep 1; done' > > > > The OP sent me some data. The following is cooked data from what I > > got: > > > > TSC Delta Elapsed Time > > ---------------+---------------+------------ > > 2245026970 > > 2249708604 4681634 0.3003693189 > > 2255874998 6166394 0.3956301509 > > 2260656402 4781404 0.3067704701 > > 2261993048 1336646 0.0857579744 > > 2264175164 2182116 0.1400025497 > > 2266445706 2270542 0.1456758803 > > 2266987003 541297 0.0347291162 > > 2267645095 658092 0.0422225757 > > 2268274965 629870 0.0404118782 > > 2268979787 704822 0.0452207294 > > 2270482069 1502282 0.0963850274 > > 2271140877 658808 0.0422685136 > > > > HPET Delta Elapsed Time > > ---------------+---------------+------------ > > 1322734365 > > 1337156221 14421856 1.0072408644 > > 1351548130 14391909 1.0051493276 > > 1365949265 14401135 1.0057936833 > > 1380376349 14427084 1.0076059946 > > 1394823985 14447636 1.0090413726 > > 1409273964 14449979 1.0092050107 > > 1423719753 14445789 1.0089123757 > > 1438167064 14447311 1.0090186742 > > 1452613630 14446566 1.0089666424 > > 1467062977 14449347 1.0091608710 > > 1481522037 14459060 1.0098392393 > > 1495969404 14447367 1.0090225853 > > > > As you can see, HPET increases normally (within errors from > > sleep(3) accuracy, syscall overhead, etc.) but TSC-low is totally > > erratic (and too low). I don't know how this can happen, though. > > :-( > > > > I need some time to figure it out. > > Can you please test the attached patch? Theoretically, it should not > make a difference but I'd like to see if it does, just in case.
As you suspected, it doesn't seem to make a difference:
fk@r500 ~/test/freebsd/timeissues $awk '/low.counter/ { o=c; c=$2; d=o?c-o:"-";
print c " " d }' kern.timecounter2
3065017784 -
3066228257 1210473
3074551564 8323307
3081121276 6569712
3084706794 3585518
3087211252 2504458
3090413096 3201844
3100133126 9720030
3104014847 3881721
3105442070 1427223
fk@r500 ~/test/freebsd/timeissues $awk '/HPET.counter/ { o=c; c=$2;
d=o?c-o:"-"; print c " " d }' kern.timecounter2
3544564602 -
3559020869 14456267
3573467329 14446460
3587889861 14422532
3602318403 14428542
3616764316 14445913
3631211075 14446759
3645625298 14414223
3660038347 14413049
3674482395 14444048
The unfiltered data is attached.
Fabian
kern.timecounter2
Description: Binary data
signature.asc
Description: PGP signature
