According to this article http://kerneltrap.org/node/11773 it says ' each level of nice adds or substracts 10% of CPU utilization, "*the '10% effect' is relative and cumulative: from _any_ nice level, if you go up 1 level, it's -10% CPU usage, if you go down 1 level it's +10% CPU usage.*" '
Is this applicable to Android kernel? since I haven't calculated the CPU usage will it give a different result when changing the nice values? can any body give some ideas?? On Wed, Jun 27, 2012 at 1:09 PM, Kanishka Ariyapala <[email protected]>wrote: > Looked in to the clock_gettime() it is not going to work as it has to be > called inside the process, also it gives the total time taken for a > function to complete. This will include the time other processes was using > the CPU as well ryt? > > Yes my goal was to make a process consume more processor by lowering the > nice value. Thank you for the link it explained it nicely. However I did a > calculation using only utime(process time spent in user space) it didn't > show any significant increase after lowering nice and worse when the > application is in the background( by pressing the home button) utime > difference is zero. Don't know if kernel space time is increased, but seems > very unlikely. > > These are the results, > pid: 263 > dutime: 8 7786 7778 > priority: 10 > nice: -10 > > pid: 263 > dutime: 8 7794 7786 > priority: 15 > nice: -5 > > pid: 263 > dutime: 7 7801 7794 > priority: 15 > nice: -5 > > pid: 263 > dutime: 4 7805 7801 > priority: 15 > nice: -5 > > pid: 263 > dutime: 9 7814 7805 > priority: 15 > nice: -5 > > pid: 263 > dutime: 8 7822 7814 > priority: 5 > nice: -15 > > dutime is the difference of utimes in 5 second intervals. > > when it's pushed in to the background, > > pid: 263 > dutime: 9 8264 8255 > priority: 5 > nice: -15 > > pid: 263 > dutime: 0 8264 8264 > priority: 5 > nice: -15 > > pid: 263 > dutime: 0 8264 8264 > priority: 5 > nice: -15 > > the difference in utime is zero.. > > So this brings up a new question, How can I make a process consume MORE > processor time? > > Any ideas? > > > On Wed, Jun 27, 2012 at 2:34 AM, Alexander Ray <[email protected]> wrote: > >> I don't quite understand what you're trying to do here. Is the goal to >> make a process consume more processor? If you run a process at a higher >> priority, it isn't guaranteed to take more cpu time. For example, a >> heavily i/o bound process could just be woken up a bit faster after >> blocking, but still consume the same processor time. >> >> As far as calculating cpu usage of a process, this stackoverflow >> question<http://stackoverflow.com/questions/1420426/calculating-cpu-usage-of-a-process-in-linux> >> answers >> it better than I could. >> >> Might be able to give a better answer if you explained a bit more about >> your use case. >> >> ~Alex >> >> >> On Wed, Jun 27, 2012 at 1:32 AM, Kanishka Ariyapala < >> [email protected]> wrote: >> >>> I looked in to the /proc/<pid>/stat and it gives some use full >>> information about the process. There are many time variables and what >>> should I use to calculate the CPU time? >>> >>> Also is there a way to measure if the CPU time slice has increased or >>> the frequency of getting the CPU has in creased after a renice? >>> >>> here is an output of /proc/<pid>/stat, >>> >>> # ./procstat 1142 >>> pid: 1142 >>> tcomm: (com.test.noise3) >>> state: S >>> ppid: 37 >>> pgid: 37 >>> sid: 0 >>> tty_nr: 0 >>> tty_pgrp: -1 >>> flags: 4194624 >>> min_flt: 6040 >>> cmin_flt: 0 >>> maj_flt: 0 >>> cmaj_flt: 0 >>> utime: 11.590000 >>> stime: 7.790000 >>> cutime: 0.000000 >>> cstime: 0.000000 >>> priority: 20 >>> nice: 0 >>> num_threads: 8 >>> it_real_value: 0.000000 >>> start_time: 06.25 15:24 (2698.61s) >>> vsize: 137080832 >>> rss: 5090 >>> rsslim: 4294967295 >>> start_code: 32768 >>> end_code: 36524 >>> start_stack: 3199794400 >>> esp: 3199793352 >>> eip: 2949704456 >>> pending: 0000000000000000 >>> blocked: 0000000000001204 >>> sigign: 0000000000000000 >>> sigcatch: 00000000000094e8 >>> wchan: 4294967295 >>> zero1: 0 >>> zero2: 0 >>> exit_signal: 0000000000000011 >>> cpu: 0 >>> rt_priority: 0 >>> policy: 0 >>> # >>> >>> can any body give some ideas? >>> >>> >>> On Tue, Jun 26, 2012 at 8:20 AM, kanishka <[email protected]> wrote: >>> >>>> Hi all, >>>> >>>> I want to measure if there is any increase in CPU usage by a process >>>> after issuing the renice command. top gives CPU usage as a percentage, is >>>> there a way to measure the time a process spent on the CPU in mili/nano >>>> seconds? >>>> >>>> What are the other possible ways of achieving this? >>>> >>>> Kanishka >>>> >>>> -- >>>> unsubscribe: [email protected] >>>> website: http://groups.google.com/group/android-kernel >>> >>> >>> -- >>> unsubscribe: [email protected] >>> website: http://groups.google.com/group/android-kernel >>> >> >> -- >> unsubscribe: [email protected] >> website: http://groups.google.com/group/android-kernel >> > > -- unsubscribe: [email protected] website: http://groups.google.com/group/android-kernel
