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.
Transparent huge pages (also new in 2.6.38) have caused about 5% degradation in memory bandwidth (measured by STREAM benchmarks and other kernels, independent of the use of software prefetch) on my machines. This is somewhat strange because huge pages should help this benchmark.
[+] [-] jerf|15 years ago|reply
[+] [-] vimes656|15 years ago|reply
[+] [-] lloeki|15 years ago|reply
[+] [-] moondowner|15 years ago|reply
[1] http://kernelnewbies.org/Linux_2_6_38
[+] [-] jedbrown|15 years ago|reply
[+] [-] tagx|15 years ago|reply