| From | Alexander Shishkin <> | Subject | Re: [PATCH v5 11/20] x86: perf: Intel PT and LBR/BTS are mutually exclusive | Date | Fri, 24 Oct 2014 10:47:16 +0300 |
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Peter Zijlstra <peterz@infradead.org> writes:
> On Mon, Oct 13, 2014 at 04:45:39PM +0300, Alexander Shishkin wrote: >> Intel PT cannot be used at the same time as LBR or BTS and will cause a >> general protection fault if they are used together. In order to avoid >> fixing up GPs in the fast path, instead we use flags to indicate that >> that one of these is in use so that the other avoids MSR access altogether. >> > > Yeah, don't like this. Like I've said many times before we should simply > disallow creating PT events when there are LBR events and vice versa.
Ok, I must have misunderstood you before. This makes things a bit easier.
Regards, -- Alex
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