Messages in this thread | | | Date | Thu, 5 Jun 2014 19:39:55 +0300 | Subject | Re: [PATCH 9/9] perf/x86: add syfs entry to disable HT bug workaround | From | Maria Dimakopoulou <> |
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On Thu, Jun 5, 2014 at 6:17 PM, Borislav Petkov <bp@alien8.de> wrote: > On Thu, Jun 05, 2014 at 05:45:24PM +0300, Maria Dimakopoulou wrote: >> The issue is that the outcoming leaked counts are not compensated >> by the incoming leaked counts of the sibling thread. With the workaround, >> corrupting events are always scheduled with an empty sibling counter. >> This means that their leaked counts are lost. So it is expected to see >> lower counts with the workaround. Note that this is not a side-effect of >> the workaround; leaked counts are expected to be lost with nothing >> measured on the sibling counter in general. >> >> In a second series we intend to re-integrate the counts for counting mode >> events. The workaround makes this easier because it guarantees >> that the sibling counter is unused, thus its counts are purely leaked >> counts and they can be safely re-integrated. > > IIUC, sounds to me like reintegrating the leaked counts from the unused > counter should be part of the workaround too, not a second series... >
This series aims to avoid corruption of non-corrupting events. Re-integration of the counts is not related to this. This is why we chose to fix this other problem on a second series to keep things clean and concepts separated.
> -- > Regards/Gruss, > Boris. > > Sent from a fat crate under my desk. Formatting is fine. > --
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