On Tue, Jun 16, 2009 at 02:09:38PM -0400, Gregory Haskins wrote: > > What do you mean by copy_to_user(other->mm) here? If you are going to > > switch > > to another mm, then I think current->mm must be valid (I think it's not > > enough > > that you can sleep). So preemptible() might not be enough. > > > > I dont currently use switch_mm, if that is what you mean. I save the > task_struct into the appropriate context so current->mm doesn't matter > to me. I never use it. All I need (afaik) is to acquire the proper > mutex first. I am not an MM expert, so perhaps I have this wrong but it > does appear to work properly even from kthread context. > > -Greg > >
I think I saw get_user_pages + memcpy in your patch. Yes, that works without switching contexts but it's slower than copy to user if you are in the right context, and AFAIK it's slower than get_user_pages_fast. -- MST -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
