From: Frederic Weisbecker Date: Fri, 26 Apr 2013 13:16:31 +0000 (+0200) Subject: nohz: Select VIRT_CPU_ACCOUNTING_GEN from full dynticks config X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=c58b0df12a6b5c497637db0676effd00e1fbab13;p=linux-beck.git nohz: Select VIRT_CPU_ACCOUNTING_GEN from full dynticks config Turn the full dynticks passive dependency on VIRT_CPU_ACCOUNTING_GEN to an active one. The full dynticks Kconfig is currently hidden behind the full dynticks cputime accounting, which is an awkward and counter-intuitive layout: the user first has to select the dynticks cputime accounting in order to make the full dynticks feature to be visible. We definetly want it the other way around. The usual way to perform this kind of active dependency is use "select" on the depended target. Now we can't use the Kconfig "select" instruction when the target is a "choice". So this patch inspires on how the RCU subsystem Kconfig interact with its dependencies on SMP and PREEMPT: we make sure that cputime accounting can't propose another option than VIRT_CPU_ACCOUNTING_GEN when NO_HZ_FULL is selected by using the right "depends on" instruction for each cputime accounting choices. v2: Keep full dynticks cputime accounting available even without full dynticks, as per Paul McKenney's suggestion. Reported-by: Ingo Molnar Signed-off-by: Frederic Weisbecker Cc: Christoph Lameter Cc: Hakan Akkan Cc: Ingo Molnar Cc: Kevin Hilman Cc: Li Zhong Cc: Paul E. McKenney Cc: Paul Gortmaker Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner --- diff --git a/init/Kconfig b/init/Kconfig index edc8132584f1..8f97a7407714 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -306,7 +306,7 @@ choice # Kind of a stub config for the pure tick based cputime accounting config TICK_CPU_ACCOUNTING bool "Simple tick based cputime accounting" - depends on !S390 + depends on !S390 && !NO_HZ_FULL help This is the basic tick based cputime accounting that maintains statistics about user, system and idle time spent on per jiffies @@ -316,7 +316,7 @@ config TICK_CPU_ACCOUNTING config VIRT_CPU_ACCOUNTING_NATIVE bool "Deterministic task and CPU time accounting" - depends on HAVE_VIRT_CPU_ACCOUNTING + depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL select VIRT_CPU_ACCOUNTING help Select this option to enable more accurate task and CPU time @@ -346,7 +346,7 @@ config VIRT_CPU_ACCOUNTING_GEN config IRQ_TIME_ACCOUNTING bool "Fine granularity task level IRQ time accounting" - depends on HAVE_IRQ_TIME_ACCOUNTING + depends on HAVE_IRQ_TIME_ACCOUNTING && !NO_HZ_FULL help Select this option to enable fine granularity task irq time accounting. This is done by reading a timestamp on each diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index 1ea2bba4a686..a2ddd650cb92 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -104,11 +104,13 @@ config NO_HZ_FULL depends on SMP # RCU_USER_QS dependency depends on HAVE_CONTEXT_TRACKING - depends on VIRT_CPU_ACCOUNTING_GEN + # VIRT_CPU_ACCOUNTING_GEN dependency + depends on 64BIT select NO_HZ_COMMON select RCU_USER_QS select RCU_NOCB_CPU select RCU_NOCB_CPU_ALL + select VIRT_CPU_ACCOUNTING_GEN select CONTEXT_TRACKING_FORCE select IRQ_WORK help