On Wed, Feb 25, 2015 at 11:38:07AM -0500, riel@xxxxxxxxxx wrote: > From: Rik van Riel <riel@xxxxxxxxxx> > > 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 <peterz@xxxxxxxxxxxxx> > Cc: Clark Williams <williams@xxxxxxxxxx> > Cc: Li Zefan <lizefan@xxxxxxxxxx> > Cc: Ingo Molnar <mingo@xxxxxxxxxx> > Cc: Luiz Capitulino <lcapitulino@xxxxxxxxxx> > Cc: Mike Galbraith <umgwanakikbuti@xxxxxxxxx> > Cc: cgroups@xxxxxxxxxxxxxxx > Signed-off-by: Rik van Riel <riel@xxxxxxxxxx> > Tested-by: David Rientjes <rientjes@xxxxxxxxxx> 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) <peterz@xxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
