Hello,

there are patches that enable clock event on ixp4xx platform. This should
enable high resolution timers... Option for hrtimers in menuconfig is 
also enabled.

I tested it on nanosleep test program (included in attachments) and obtained
this results:

requested: 899000 us, got: 899159 us, diff: -159 us
requested: 897000 us, got: 897209 us, diff: -209 us
requested: 895000 us, got: 899803 us, diff: -4803 us
requested: 893000 us, got: 899425 us, diff: -6425 us
requested: 891000 us, got: 899806 us, diff: -8806 us
requested: 889000 us, got: 890142 us, diff: -1142 us
requested: 887000 us, got: 889873 us, diff: -2873 us
requested: 885000 us, got: 888096 us, diff: -3096 us
requested: 883000 us, got: 883323 us, diff: -323 us
requested: 881000 us, got: 883395 us, diff: -2395 us
requested: 879000 us, got: 883026 us, diff: -4026 us
requested: 877000 us, got: 877838 us, diff: -838 us
requested: 875000 us, got: 876975 us, diff: -1975 us
requested: 873000 us, got: 873585 us, diff: -585 us
requested: 871000 us, got: 871699 us, diff: -699 us
requested: 869000 us, got: 869747 us, diff: -747 us
requested: 867000 us, got: 869771 us, diff: -2771 us
requested: 865000 us, got: 869777 us, diff: -4777 us
requested: 863000 us, got: 869774 us, diff: -6774 us
requested: 861000 us, got: 869744 us, diff: -8744 us
requested: 859000 us, got: 861180 us, diff: -2180 us
requested: 857000 us, got: 857108 us, diff: -108 us
requested: 855000 us, got: 860986 us, diff: -5986 us
requested: 853000 us, got: 858383 us, diff: -5383 us
requested: 851000 us, got: 855234 us, diff: -4234 us
requested: 849000 us, got: 850261 us, diff: -1261 us
requested: 847000 us, got: 848729 us, diff: -1729 us
requested: 845000 us, got: 845926 us, diff: -926 us
requested: 843000 us, got: 844059 us, diff: -1059 us
requested: 841000 us, got: 841498 us, diff: -498 us
requested: 839000 us, got: 839758 us, diff: -758 us
requested: 837000 us, got: 839748 us, diff: -2748 us
requested: 835000 us, got: 839727 us, diff: -4727 us
requested: 833000 us, got: 834417 us, diff: -1417 us
requested: 831000 us, got: 834710 us, diff: -3710 us
requested: 829000 us, got: 834696 us, diff: -5696 us
requested: 827000 us, got: 830714 us, diff: -3714 us
requested: 825000 us, got: 830543 us, diff: -5543 us
requested: 823000 us, got: 830812 us, diff: -7812 us
requested: 821000 us, got: 828395 us, diff: -7395 us
requested: 819000 us, got: 819855 us, diff: -855 us
requested: 817000 us, got: 818855 us, diff: -1855 us
requested: 815000 us, got: 817711 us, diff: -2711 us
requested: 813000 us, got: 813312 us, diff: -312 us
requested: 811000 us, got: 811901 us, diff: -901 us
requested: 809000 us, got: 809804 us, diff: -804 us
requested: 807000 us, got: 809790 us, diff: -2790 us
requested: 805000 us, got: 809798 us, diff: -4798 us
requested: 803000 us, got: 809243 us, diff: -6243 us
requested: 801000 us, got: 801482 us, diff: -482 us
requested: 799000 us, got: 799772 us, diff: -772 us
requested: 797000 us, got: 801161 us, diff: -4161 us
requested: 795000 us, got: 798107 us, diff: -3107 us
requested: 793000 us, got: 795470 us, diff: -2470 us
requested: 791000 us, got: 793550 us, diff: -2550 us
requested: 789000 us, got: 789249 us, diff: -249 us
requested: 787000 us, got: 789163 us, diff: -2163 us
requested: 785000 us, got: 785329 us, diff: -329 us
requested: 783000 us, got: 783539 us, diff: -539 us
requested: 781000 us, got: 781949 us, diff: -949 us
requested: 779000 us, got: 779836 us, diff: -836 us
requested: 777000 us, got: 779785 us, diff: -2785 us
requested: 775000 us, got: 779804 us, diff: -4804 us
requested: 773000 us, got: 779805 us, diff: -6805 us
requested: 771000 us, got: 779811 us, diff: -8811 us
requested: 769000 us, got: 769796 us, diff: -796 us
requested: 767000 us, got: 769803 us, diff: -2803 us
requested: 765000 us, got: 769030 us, diff: -4030 us
requested: 763000 us, got: 771035 us, diff: -8035 us
requested: 761000 us, got: 761268 us, diff: -268 us
requested: 759000 us, got: 759746 us, diff: -746 us
requested: 757000 us, got: 757719 us, diff: -719 us
requested: 755000 us, got: 757442 us, diff: -2442 us
requested: 753000 us, got: 754198 us, diff: -1198 us
requested: 751000 us, got: 751350 us, diff: -350 us
requested: 749000 us, got: 749765 us, diff: -765 us
requested: 747000 us, got: 749758 us, diff: -2758 us

Results are far better than on standart kernel, but...

My question is: are these numbers expected? I hoped that with
hrtimers get better numbers, something about hundrets of us, instead
of thoushands...

The CONFIG_HIGH_RES_RESOLUTION is 100000 but
numbers were roughly the same with the default 1000. Numbers are
the same also when nanosleep and kernel threads are boosted to use
rt round-robin priority...

The system is running only this program.

Patch is against 2.6.17-rt7.

Feedback and comments are highly appreciated.

Signed-off-by: Milan Svoboda <msvoboda@ra.rockwell.com>
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