Not that it so far appears to be a problem, but where kapm-idled used
to wait a tad after activity and then apparently gobble up all the
extra CPU cycles (in 2.4.10-ac1) I now notice that xosview is showing
CPU usage when things are quiet as hopping up and down, and top is
reporting kapm-idled CPU usage as in the mid to high 50 percent range.
Under 2.4.10-ac1 top used to put kapm-idled in the very high 90
percent range.
Does this mean my laptop will get less battery life?
Thanks,
-kb, the Kent with too wimpy a battery as it is.
P.S. I am on a Sony Viao PCG-Z505LE.
> extra CPU cycles (in 2.4.10-ac1) I now notice that xosview is showing
> CPU usage when things are quiet as hopping up and down, and top is
> reporting kapm-idled CPU usage as in the mid to high 50 percent range.
>
> Under 2.4.10-ac1 top used to put kapm-idled in the very high 90
> percent range.
>
> Does this mean my laptop will get less battery life?
Is your laptop logging messages in the process ? (dmesg)
One thing I changed in -ac was to do sane things when the apm idle request
comes back with "no" from the BIOS
Alan
"Alan Cox wrote:"
> One thing I changed in -ac was to do sane things when the apm idle request
> comes back with "no" from the BIOS
HURRAY!!!!
Peter
On Fri, Oct 12, 2001 at 03:21:57PM +0100, Alan Cox wrote:
> Is your laptop logging messages in the process ? (dmesg)
No. I don't see any ongoing logging from apm. Looking at dmesg I see
boot stuff about battery minutes having swapped bytes, some version
and flag printk's, but no current logging.
In /var/spool/messages I also see mention of the times I have
suspended and awakened my laptop, but no other ongoing loggin there
either.
> One thing I changed in -ac was to do sane things when the apm idle request
> comes back with "no" from the BIOS
I had noticed that comment, which made me think it might be of
specific interest.
Thanks,
-kb
> I am having almost the same problem in 2.4.12-ac1:
>
> gallir@linux:~$ uname -a
> Linux linux 2.4.12-ac1 #2 Fri Oct 12 19:01:03 CEST 2001 i686 unknown
>
> kapm-idled consumes a 14% of CPU (in a P3 1GHz)
>
> PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND
> 3 root 17 0 0 0 0 RW 14.3 0.0 1:17 kapm-idled
>
> The same happens with vanilla Linus tree (tested up to 2.4.11). In a P2,
> CPU consuption was more than 85%.
>
> The CPU's temperature, while the system idle, is more than 4 degrees (C)
> higher than the same conditions with the kapm-idled disabled.
I've been reading throught the APM spec and code a bit further. The more
I read the more I wonder quite how our idle code is meant to work and what
kind of beer was overconsumed during its writing.
There are two glaring issues I can see right now
#1 The BIOS might sleep for a tick, but it is also is allowed to slow
the cpu and return straight back to us.
If it returns back to us we spin in a tight loop at the lower clock
speed calling the APM bios. Not ideal.
Just fixed that in my tree for the next -ac
#2 We test system_idle() nr_running==1, but we spent all our time
pretending we aren't running. Im not 100% sure the test is safe
yet
Alan