investigated this myself littlebit: Indeed the top only knows about currently configured cpu frequency so if power management has set it to 245Mhz on nexusone then com.android.wallpaper app can easily show 20..30% cpu usage but at 499mhz the cpu usage is ~12%...
Found a nice solution to this: to get cpu usage % that is not affected by power management decisions one can install setCPU app (http://forum.xda-developers.com/showthread.php?t=505419) This allows you to modify min & max possible cpu frequency. When setting min freq == max freq I can compare cpu usage % between different experiments without having to worry about what frequency power management decides to use during experiment. Br, Lauri On Apr 1, 4:54 pm, Lauri Ehrenpreis <[email protected]> wrote: > Hi! > > The easiest way to get some idea about cpu usage on android seems to > be the top utility (adb shell top) > However it seems to me that due to power management the cpu frequency > is changing all the time (i can see this when doing cat /proc/cpuinfo > - the BogoMIPS value is changing drastically). So the question is that > how does top calculate the cpu usage percent? Is it aware of max > possible cpu frequency and calculates based on that or it calculates > based on current cpu frequency? > > Consider these 2 cases: > 1) BogoMIPS shows 100 while top says my process takes 50% of the cpu > 2) BocoMIPS shows 600 while top says my process takes 50% of the cpu > Does this mean that in first case my process was eating 50 BogoMIPS > and in second case 300 (top is not aware of max possible cpu freq)? or > in both cases my process took same amount of cpu (top is aware of max > freq)? > > Br, > Lauri -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en To unsubscribe, reply using "remove me" as the subject.
