It isn't just me then, huh? I tried to bisect my way to a precise patch but it's really hard when you have ~15 steps, it's hard to tell if it "works" or not in anything less than an hour, and if you're wrong once you're guaranteed not to find the correct one. And the results I got almost make me think it's actually more than one patch combining together such that it has actually gotten gradually worse over time, which makes it even harder to finger.

I installed/upgraded ArchLinux (which is at 2.6.38 now) on a bunch of laptops lately and noticed a raise in power usage (in the range of 10%), with mostly some high kworker activity (100+ wakeup/s when idle, that's 80% of overall wakeups) in powertop. But the worst contender has been s2ram power usage: the laptops go to sleep yet leaving them sleeping overnight pumps 40% out of the battery (should be 2~4%, tops). Unfortunately I can't downgrade easily as .38 introduced proper support for core components of those laptops.

.38 introduced lot's of new stuff [1], so regressions can occur I guess. But I know that it'll get fixed. By the time this news got to HN there's probably someone working on it.

[1] http://kernelnewbies.org/Linux_2_6_38

It will be interesting to see how this plays out when Ubuntu 11.04 which uses 2.6.38 is released.