Messages in this thread | | | From | Gaurav Poothia <> | Date | Thu, 21 Jul 2016 12:03:47 -0700 | Subject | Question about group scheduler cpu shares |
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Hi, The cgroup "cpu" subsystem's weight calculation using "cpu shares" is fairly clear when all tasks are attached to the leaf cgroups in "cpu" subsystem. For example in this cgroup hierarchy with tasks A.B,C and D and associated cpu shares:
ROOT | + -Group1(3072) | | | +- A(2048) | | | +- B(1024) | +- Group2(2048) | +-C(1024) | +-D(1024)
Group 1 and Group 2 split the CPU 60% to 40% respectively A and B split Group1's 60% share 2/3rd to 1/3rd so absolute share of CPU will be 40% and 20% respectively C and D split Group2's 40% share evenly so absolute shares or 20% each So far so good. But in this example all tasks are associated with leaf cgroups.
Say I add a task E to Group1's task list (note that is an interior aka non-leaf node) How does the CPU split change between A, B and E. AFAICT there is no cgroup cpu subsystem knob to weight tasks on an interior node against the tasks in that node's children
Thanks in advance! Gaurav
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