Messages in this thread | | | Date | Sat, 19 Apr 2008 17:23:11 -0400 | From | Mathieu Desnoyers <> | Subject | Re: [RFC PATCH] x86 NMI-safe INT3 and Page Fault (v5) |
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* Andi Kleen (andi@firstfloor.org) wrote: > Mathieu Desnoyers <compudj@krystal.dyndns.org> writes: > > > > It uses RCU-style updates and has been designed to be lockless from the > > ground up. > > RCU is not necessarily NMI safe. In most cases RCU needs writer locks > which you cannot do with NMIs. > > -Andi >
RCU-style updates are done outside of NMIs, in sleepable context. That's just required when the probes connected on markers must be registered/unregistered.
The NMI context is the RCU read side. It only have to get the probe function pointers to call along with the private data pointers.
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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