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    nohz: Select VIRT_CPU_ACCOUNTING_GEN from full dynticks config · c58b0df1
    Frederic Weisbecker 提交于
    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: NIngo Molnar <mingo@kernel.org>
    Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
    Cc: Christoph Lameter <cl@linux.com>
    Cc: Hakan Akkan <hakanakkan@gmail.com>
    Cc: Ingo Molnar <mingo@kernel.org>
    Cc: Kevin Hilman <khilman@linaro.org>
    Cc: Li Zhong <zhong@linux.vnet.ibm.com>
    Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
    Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Steven Rostedt <rostedt@goodmis.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    c58b0df1
Kconfig 4.2 KB