Messages in this thread | | | Subject | Re: [RFC PATCH 5/5] refresh VM committed space after a task migration | From | Dave Hansen <> | Date | Tue, 10 Jun 2008 10:41:28 -0700 |
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On Tue, 2008-06-10 at 01:33 +0200, Andrea Righi wrote: > + preempt_disable(); > + committed = atomic_long_read(&p->vm_committed_space); > + atomic_long_sub(committed, &old_mem->vmacct.vm_committed_space); > + atomic_long_add(committed, &mem->vmacct.vm_committed_space); > + preempt_enable(); > out: > mmput(mm); > }
Why bother with the preempt stuff here? What does the actually protect against? I assume that you're trying to keep other tasks that might run on this CPU from seeing weird, inconsistent numbers in here. Is there some other looks that keeps *other* cpus from seeing this?
In any case, I think it needs a big, fat comment.
-- Dave
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