Re: [announce] Intel announces the PowerTOP utility for Linux

Jan Engelhardt
2007-05-12T11:01:25Z

On May 11 2007 16:07, Arjan van de Ven wrote:
>
> A typical Linux distribution has many components that wake the processor up
> frequently for no good reason. In our testing with PowerTOP, we have seen many
> cases where with some simple fixes, the battery life of typical laptops was
> increased by one hour or more!
>
> We are providing fixes for several of the issues we identified, and we
> encourage the Linux community to help us in this quest to get the maximum
> battery life out of your (hopefully Intel based) laptops. Try the PowerTOP
> tool, join the mailing list or the IRC channel and provide feedback, problem
> reports or fixes!

Yeah, hal happily wakes up every two seconds. So much for
the effectivity of NO_HZ.

# ps afx | grep hal
...
3003 ? S 0:00 \_ hald-addon-storage: polling /dev/hdb
...
# strace -p 3003
Process 3003 attached - interrupt to quit
restart_syscall(<... resuming interrupted call ...>) = 0
open("/dev/hdb", O_RDONLY|O_NONBLOCK|O_EXCL|O_LARGEFILE) = 4
ioctl(4, CDROM_DRIVE_STATUS, 0x7fffffff) = 1
close(4) = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGCHLD, NULL, {SIG_DFL}, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
nanosleep({2, 0}, {2, 0}) = 0
open("/dev/hdb", O_RDONLY|O_NONBLOCK|O_EXCL|O_LARGEFILE) = 4
ioctl(4, CDROM_DRIVE_STATUS, 0x7fffffff) = 1
close(4) = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGCHLD, NULL, {SIG_DFL}, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
nanosleep({2, 0}, {2, 0}) = 0
open("/dev/hdb", O_RDONLY|O_NONBLOCK|O_EXCL|O_LARGEFILE) = 4
ioctl(4, CDROM_DRIVE_STATUS, 0x7fffffff) = 1
close(4) = 0
rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0
rt_sigaction(SIGCHLD, NULL, {SIG_DFL}, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
nanosleep({2, 0}, <unfinished ...>

Jan
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