Hello,
I found negative numbers sometimes appear in /proc/latency_stats
(vanilla kernel 2.6.29-rc3, on x86 cpu, configuration attached)

[corrado@localhost ~]$ while sleep 1; do grep -- - /proc/latency_stats
>> neg_stats; done
^Z
[1]+  Stopped                 sleep 1
[corrado@localhost ~]$ cat neg_stats
1 -486373534 -486373534 sys_rt_sigsuspend sysenter_do_call
1 -486373534 -486373534 sys_rt_sigsuspend sysenter_do_call
1 -486373534 -486373534 sys_rt_sigsuspend sysenter_do_call


I suspect this can be the cause for
https://bugs.launchpad.net/ubuntu/+source/latencytop/+bug/297776 , as
I saw it happening on my machine during a kernel recompilation.

Corrado