| Subject | Re: [PATCH 12/35] autonuma: CPU follow memory algorithm | From | Peter Zijlstra <> | Date | Tue, 29 May 2012 15:10:04 +0200 |
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On Fri, 2012-05-25 at 19:02 +0200, Andrea Arcangeli wrote: > + * This function is responsible for deciding which is the best CPU > + * each process should be running on according to the NUMA > + * affinity. To do that it evaluates all CPUs and checks if there's > + * any remote CPU where the current process has more NUMA affinity > + * than with the current CPU, and where the process running on the > + * remote CPU has less NUMA affinity than the current process to run > + * on the remote CPU. Ideally this should be expanded to take all > + * runnable processes into account but this is a good > + * approximation. When we compare the NUMA affinity between the > + * current and remote CPU we use the per-thread information if the > + * remote CPU runs a thread of the same process that the current task > + * belongs to, or the per-process information if the remote CPU runs > a > + * different process than the current one. If the remote CPU runs the > + * idle task we require both the per-thread and per-process > + * information to have more affinity with the remote CPU than with > the > + * current CPU for a migration to happen.
This doesn't explain anything in the dense code that follows.
What statistics, how are they used, with what goal etc..
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