Re: [RFC PATCH] x86 NMI-safe INT3 and Page Fault (v5)

From: Mathieu Desnoyers
Date: Sat Apr 19 2008 - 17:05:43 EST


* Andi Kleen (andi@xxxxxxxxxxxxxx) wrote:
> Mathieu Desnoyers wrote:
> > * Andi Kleen (andi@xxxxxxxxxxxxxx) wrote:
> >> Mathieu Desnoyers <compudj@xxxxxxxxxxxxxxxxxx> writes:
> >>> It allows placing immediate values (and therefore optimized trace_marks) in NMI
> >>> code
> >> Only if all your trace_mark infrastructure is lock less.
> >>
> >> -Andi
> >>
> >
> > It uses RCU-style updates and has been designed to be lockless from the
> > ground up.
>
> Wrong. If it causes vmalloc faults it is not lockless.
>
> -Andi
>

Could you point me where vmalloc_fault accesses a data structure for
which updates are protected by disabling interrupts ? I am curious.

Mathieu


--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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