Messages in this thread | | | Subject | Re: [PATCH 4/4] nohz: Set isolcpus when nohz_full is set | From | Mike Galbraith <> | Date | Mon, 18 May 2015 16:22:11 +0200 |
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On Mon, 2015-05-18 at 10:07 -0400, Rik van Riel wrote: > On 05/17/2015 11:29 PM, Mike Galbraith wrote: > > On Sun, 2015-05-17 at 22:17 -0400, Rik van Riel wrote: > >> On 05/17/2015 01:30 AM, Mike Galbraith wrote: > >> > >>> Given that kernel initiated association to isolcpus, a user turning > >>> NO_HZ_FULL_ALL on had better not have much generic load to manage. If > >>> he/she does not have CPUSETS enabled, or should Rik's patch rendering > >>> isolcpus immutable be merged, > >> > >> My patch does not aim to make isolcpus immutable, it aims to make > >> isolcpus resistent to system management tools (like libvirt) > >> automatically undoing isolcpus the instant a cpuset with the default > >> cpus (inherited from the root group) is created. > > > > Aim or not, if cpusets is the sole modifier, it'll render isolcpus > > immutable, no? Cpusets could grow an override to the override I > > suppose, to regain control of the resource it thinks it manages. > > The other way would be to make /sys/devices/system/cpu/isolcpus > (which Greg KH promised he would queue up for 4.2) writable.
Anything is better than override the override. That's easy, but the changelog would have to be farmed out to a talented used car salesman.
-Mike
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