On Tue, Sep 12, 2023 at 10:26:06AM +0200, Peter Zijlstra wrote: > > How expensive would be always having PREEMPT_COUNT=y? > > Effectively I think that is true today. At the very least Debian and > SuSE (I can't find a RHEL .config in a hurry but I would think they too) > ship with PREEMPT_DYNAMIC=y. $ grep PREEMPT uek-rpm/ol9/config-x86_64 # CONFIG_PREEMPT_NONE is not set CONFIG_PREEMPT_VOLUNTARY=y # CONFIG_PREEMPT is not set CONFIG_HAVE_PREEMPT_DYNAMIC=y CONFIG_PREEMPT_NOTIFIERS=y CONFIG_DRM_I915_PREEMPT_TIMEOUT=640 # CONFIG_PREEMPTIRQ_DELAY_TEST is not set $ grep PREEMPT uek-rpm/ol9/config-aarch64 # CONFIG_PREEMPT_NONE is not set CONFIG_PREEMPT_VOLUNTARY=y # CONFIG_PREEMPT is not set CONFIG_PREEMPT_NOTIFIERS=y # CONFIG_PREEMPTIRQ_DELAY_TEST is not set
