Messages in this thread | | | Subject | Re: [RFC][PATCH 4/5] printk: Have wake_up_klogd() use __this_cpu_write() | From | Peter Zijlstra <> | Date | Tue, 20 Sep 2011 16:55:53 +0200 |
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On Tue, 2011-09-20 at 09:54 -0500, Christoph Lameter wrote: > On Mon, 19 Sep 2011, Steven Rostedt wrote: > > > Note, just because something is always in a location that preemption is > > disabled, does not mean it should use the __this_cpu*() variants. > > Why not? If preemption is disabled then the process cannot be migrated to > another processor. And thus doing the address calculations and operations > on variables step by step is okay. > > > Because if things change, it may become a problem later on. > > What things may change? Someone calls the function with preemption > enabled?
Yes, also, for !x86 you get a redundant preempt_disable/enable pair.
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