I'm sorry but generic Linux is beyond the scope of this group. I suggest doing a web search for the specific topics you're interested in. However, here are a few links to help you get started: http://en.wikipedia.org/wiki/Completely_Fair_Scheduler http://www.ibm.com/developerworks/linux/library/l-completely-fair-scheduler/ http://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt http://lxr.linux.no/linux+v3.3/kernel/sched/fair.c
On Monday, March 19, 2012 10:22:20 AM UTC-7, Deborah wrote: > > Glenn thanks for your reply! I'm really confused. Could you explain > how the CFS work? > Does it divide the CPU time into epochs? > In a single epoch, has every process a specified time quantum that is > computed at the beginning of each epoch? > If yes, is 'virtual runtime' set to zero in each epoch or is it an > approximated average? > Help please!!! :( > > > On Mar 19, 4:21 pm, Glenn Kasten <gkas...@android.com> wrote: > > Threads voluntarily assign themselves a nice priority within the > permitted > > range, and activity manager assigns threads of an app process to an > > appropriate cpuctl cgroup. > > > > > > > > > > > > > > > > On Friday, March 16, 2012 6:38:57 AM UTC-7, Deborah wrote: > > > > > I am trying to get a better understanding on ANDROID CFS. I have some > > > doubt on scheduler's behavior. > > > The difference between Android scheduler and Linux scheduler > > > Scheduler > > > — 5 files — The Android kernel also contains slight changes to the > > > CPU > > > process scheduler and time-keeping algorithms. We don’t know the > > > history of these changes, and the impact was not evident based on a > > > cursory examination. > > > Do you know which are this files? > > > If I understand, Process.THREAD_PRIORITY_DEFAULT or > > > Process.THREAD_PRIORITY_BACKGROUND are 'nice' value. How does Android > > > convert 'nice' value in 'timeslice'? > > > What is the initial value of 'virtual runtime' in Android and how to > > > calculate? > > > In Android, is 'cgroups' use to define scheduling classes? The > > > following application states: (i) Foreground process - Critical > > > priority; (ii) Visible process and Service process - High priority; > > > (iii) Background process and Empty process - Low priority; are three > > > scheduling classes ? > > > Thanks in advance, > > > Deborah > > > > On Friday, March 16, 2012 6:38:57 AM UTC-7, Deborah wrote: > > > > > I am trying to get a better understanding on ANDROID CFS. I have some > > > doubt on scheduler's behavior. > > > The difference between Android scheduler and Linux scheduler > > > Scheduler > > > — 5 files — The Android kernel also contains slight changes to the > > > CPU > > > process scheduler and time-keeping algorithms. We don’t know the > > > history of these changes, and the impact was not evident based on a > > > cursory examination. > > > Do you know which are this files? > > > If I understand, Process.THREAD_PRIORITY_DEFAULT or > > > Process.THREAD_PRIORITY_BACKGROUND are 'nice' value. How does Android > > > convert 'nice' value in 'timeslice'? > > > What is the initial value of 'virtual runtime' in Android and how to > > > calculate? > > > In Android, is 'cgroups' use to define scheduling classes? The > > > following application states: (i) Foreground process - Critical > > > priority; (ii) Visible process and Service process - High priority; > > > (iii) Background process and Empty process - Low priority; are three > > > scheduling classes ? > > > Thanks in advance, > > > Deborah -- unsubscribe: android-kernel+unsubscr...@googlegroups.com website: http://groups.google.com/group/android-kernel
