Messages in this thread | | | Date | Mon, 21 Apr 2008 13:42:39 -0400 | From | Mathieu Desnoyers <> | Subject | Re: [RFC PATCH] x86 NMI-safe INT3 and Page Fault (v5) |
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* H. Peter Anvin (hpa@zytor.com) wrote: > Pavel Machek wrote: >>> There is also the page fault case. I think putting this test in >>> ret_from_exception would be both safe (it is executed for any >>> exception return) and fast (exceptions are rare). >> Eh? I thought that page fault is one of the hottest paths in kernel >> (along with syscall and packet receive/send)... >> Pavel >
On x86_64, we can pinpoint only the page faults returning to the kernel, which are rare and only caused by vmalloc accesses. Ideally we could do the same on x86_32.
> Yeah, and the concept of handling page faults inside an NMI handler is pure > fantasy. > > -hpa >
-- 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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