Messages in this thread | | | Date | Fri, 14 Feb 2020 14:40:08 -0500 | From | Peter Xu <> | Subject | Re: [PATCH] sched/isolation: Allow "isolcpus=" to skip unknown sub-parameters |
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On Tue, Feb 04, 2020 at 11:16:39AM -0500, Peter Xu wrote: > The "isolcpus=" parameter allows sub-parameters to exist before the > cpulist is specified, and if it sees unknown sub-parameters the whole > parameter will be ignored. This design is incompatible with itself > when we add more sub-parameters to "isolcpus=", because the old > kernels will not recognize the new "isolcpus=" sub-parameters, then it > will invalidate the whole parameter so the CPU isolation will not > really take effect if we start to use the new sub-parameters while > later we reboot into an old kernel. Instead we will see this when > booting the old kernel: > > isolcpus: Error, unknown flag > > The better and compatible way is to allow "isolcpus=" to skip unknown > sub-parameters, so that even if we add new sub-parameters to it the > old kernel will still be able to behave as usual even if with the new > sub-parameter is specified. > > Ideally this patch should be there when we introduce the first > sub-parameter for "isolcpus=", so it's already a bit late. However > late is better than nothing.
Ping - Hi, Thomas, do you have any further comment on this patch?
Thanks,
-- Peter Xu
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