what happens to processes whose process affinity is set to a disabled processor?
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I'm running Centos7 on an hyper-threaded Ivy Bridge machine with 40 cores and 80 threads.
The following for loop shows me the processor affinity for all processes with pids 10 and then rerun the for loop. The result is as follows:
pid 1's current affinity list: 0-9
pid 2's current affinity list: 0-9
pid 4's current affinity list: 0
pid 6's current affinity list: 0
pid 7's current affinity list: 0
pid 8's current affinity list: 0-9
pid 9's current affinity list: 0-9
pid 10's current affinity list: 0-9
pid 11's current affinity list: 0
pid 12's current affinity list: 1
pid 13's current affinity list: 1
pid 14's current affinity list: 1
pid 16's current affinity list: 1
pid 18's current affinity list: 2
pid 19's current affinity list: 2
pid 20's current affinity list: 2
pid 22's current affinity list: 2
pid 24's current affinity list: 3
pid 25's current affinity list: 3
pid 26's current affinity list: 3
pid 28's current affinity list: 3
pid 30's current affinity list: 4
pid 31's current affinity list: 4
pid 32's current affinity list: 4
pid 34's current affinity list: 4
pid 36's current affinity list: 5
pid 37's current affinity list: 5
pid 38's current affinity list: 5
pid 40's current affinity list: 5
pid 41's current affinity list: 6
pid 42's current affinity list: 6
pid 43's current affinity list: 6
pid 45's current affinity list: 6
pid 46's current affinity list: 7
pid 47's current affinity list: 7
pid 48's current affinity list: 7
pid 50's current affinity list: 7
pid 51's current affinity list: 8
pid 52's current affinity list: 8
pid 53's current affinity list: 8
pid 54's current affinity list: 8
pid 55's current affinity list: 8
pid 56's current affinity list: 9
pid 57's current affinity list: 9
pid 58's current affinity list: 9
pid 60's current affinity list: 9
pid 61's current affinity list:
pid 62's current affinity list:
pid 63's current affinity list:
pid 65's current affinity list:
pid 66's current affinity list:
pid 67's current affinity list:
pid 68's current affinity list:
pid 70's current affinity list:
pid 71's current affinity list:
pid 72's current affinity list:
pid 73's current affinity list:
pid 74's current affinity list:
pid 75's current affinity list:
pid 76's current affinity list:
pid 77's current affinity list:
pid 78's current affinity list:
pid 80's current affinity list:
The affinity for process with pid = 1, now shows up as 0-9 instead of 0-79. This is what I expected. However processes with pids between 66 and 80 are shown to have no affinity list. Does that mean their affinity lists are 0-9, or something else? The system seems to work just fine so these processes without affinity must be doing their jobs.
There are of course many other processes with original affinities set to processors which have been disabled. Rather than showing almost 1000 lines of output, I've just shown the results for the first 80 processes.
Asked by Richard Gostanian
(345 rep)
Sep 4, 2020, 03:25 PM