Messages in this thread | | | Date | Mon, 26 Jan 2009 15:01:24 -0800 | From | Mike Travis <> | Subject | Re: [PATCH 2/3] work_on_cpu: Use our own workqueue. |
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Ingo Molnar wrote: > * Oleg Nesterov <oleg@redhat.com> wrote: > >> But "[PATCH 1/3] work_on_cpu: dont try to get_online_cpus() in >> work_on_cpu." removes get_online_cpus/put_online_cpus, this means the >> work can run on the wrong CPU anyway. Or work_on_cpu() can hang forever >> if CPU has already gone away before queue_work_on(). >> >> Confused. > > The idea was to require work_on_cpu() users to be CPU hotplug-safe. But > ... Rusty pointed it out in the past that this might be fragile, and we > could put back the get_online_cpus()/put_online_cpus() calls. > > Rusty, what do you think? > > Ingo
I believe that is the intention, in that the caller should insure that the cpu does not go offline. But also as Rusty stated, the previous usages of set_cpus_allowed did not always insure this, so it's at least not a regression.
I'll put it on my todo list to check the references in tip/cpus4096 to see where they stand on the get_online_cpus() issue.
Thanks, Mike
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