Messages in this thread | | | Date | Tue, 9 Apr 2013 14:35:23 +0000 | From | Christoph Lameter <> | Subject | Re: [PATCH 4/4] nohz: New option to force all CPUs in full dynticks range |
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On Tue, 9 Apr 2013, Paul Gortmaker wrote:
> > 2. Avoid the setting of cpus entirely? If full nohz mode is desired > > then pick one cpu (f.e. the first one or the one that is used for xtime > > updates) and then make all other cpus nohz. Set the affinity mask for the > > rcuoXXX threads to that cpu. > > I can imagine people with multi socket systems wanting to have > a system partitioned with one "normal" core per physical socket, > for timekeeping, RCU threads, etc, but #2 would prevent that.
That is a good point. The kernel needs to run per node threads for I/O and reclaim which could have their home there. Just had some bad experience with latency introduced by the block layer redirecting I/O to the first processor of a node. Maybe we can adopt that convention and relocate kernel processing as much as possible to the first processor of a node?
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