The "isolcpus=" boot parameter support was always built-in before we moved the related code under CONFIG_CPU_ISOLATION. Having it disabled by default is very confusing for people accustomed to use this parameter.
So enable it by dafault to keep the previous behaviour but keep it optable for those who want to tinify their kernels. Signed-off-by: Frederic Weisbecker <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Chris Metcalf <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Luiz Capitulino <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Wanpeng Li <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: John Stultz <[email protected]> --- init/Kconfig | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/init/Kconfig b/init/Kconfig index 2934249..690a381 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -461,10 +461,14 @@ endmenu # "CPU/Task time and stats accounting" config CPU_ISOLATION bool "CPU isolation" + default y help Make sure that CPUs running critical tasks are not disturbed by any source of "noise" such as unbound workqueues, timers, kthreads... - Unbound jobs get offloaded to housekeeping CPUs. + Unbound jobs get offloaded to housekeeping CPUs. This is driven by + the "isolcpus=" boot parameter. + + Say Y if unsure. source "kernel/rcu/Kconfig" -- 2.7.4
