On Wed, Feb 25, 2015 at 11:38:07AM -0500, r...@redhat.com wrote: > From: Rik van Riel <r...@redhat.com> > > Ensure that cpus specified with the isolcpus= boot commandline > option stay outside of the load balancing in the kernel scheduler. > > Operations like load balancing can introduce unwanted latencies, > which is exactly what the isolcpus= commandline is there to prevent. > > Previously, simply creating a new cpuset, without even touching the > cpuset.cpus field inside the new cpuset, would undo the effects of > isolcpus=, by creating a scheduler domain spanning the whole system, > and setting up load balancing inside that domain. The cpuset root > cpuset.cpus file is read-only, so there was not even a way to undo > that effect. > > This does not impact the majority of cpusets users, since isolcpus= > is a fairly specialized feature used for realtime purposes. > > Cc: Peter Zijlstra <pet...@infradead.org> > Cc: Clark Williams <willi...@redhat.com> > Cc: Li Zefan <lize...@huawei.com> > Cc: Ingo Molnar <mi...@redhat.com> > Cc: Luiz Capitulino <lcapitul...@redhat.com> > Cc: Mike Galbraith <umgwanakikb...@gmail.com> > Cc: cgro...@vger.kernel.org > Signed-off-by: Rik van Riel <r...@redhat.com> > Tested-by: David Rientjes <rient...@google.com>
Might I asked you to update Documentation/cgroups/cpusets.txt with this knowledge? While it does mentions isolcpus it does not clarify the interaction between it and cpusets. Other than that, Acked-by: Peter Zijlstra (Intel) <pet...@infradead.org> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
