Messages in this thread | | | Subject | Re: [PATCH] [CPU-HOTPLUG] convert cpucontrol to be a rwsem | From | Rusty Russell <> | Date | Tue, 02 Nov 2004 10:48:23 +1100 |
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On Mon, 2004-11-01 at 13:04 -0500, Lee Revell wrote: > On Mon, 2004-11-01 at 07:00 -0700, Zwane Mwaikambo wrote: > > Agreed it makes a lot more sense, i think there could be some places where > > we use preempt_disable to protect against cpu offline which could > > converted, but that can come later. > > > > You know I picked up Robert Love's book the other day and was surprised > to read we are not supposed to be using preempt_disable, there is a > per_cpu interface for exactly this kind of thing. Which is currently > recommended?
get_cpu() both ensures that this CPU won't go down, and ensures we won't get scheduled off it. It returns the current processor ID, as well. put_cpu() puts the CPU back.
In my experience it's usually clearer than preempt_disable().
Cheers, Rusty. -- A bad analogy is like a leaky screwdriver -- Richard Braakman
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