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SubjectRe: [PATCH 3/3] context_tracking,x86: remove extraneous irq disable & enable from context tracking on syscall entry

* Frederic Weisbecker <fweisbec@gmail.com> wrote:

> > > We cannot take the lock_trace(task) from irq context, and we
> > > probably do not need to anyway, since we do not care about a
> > > precise stack trace for the task.
> >
> > So one worry with this and similar approaches of statistically
> > detecting user mode would be the fact that on the way out to
> > user-space we don't really destroy the previous call trace - we
> > just pop off the stack (non-destructively), restore RIPs and are
> > gone.
> >
> > We'll need that percpu flag I suspect.
>
> Note we have the context tracking state which tells where the
> current task is: user/system/guest.

Yes, but that overhead is what I'm suggesting we get rid of, I thought
Rik was trying to find a mechanism that would be independent of that?

Thanks,

Ingo


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