Messages in this thread | | | Date | Fri, 28 Oct 2016 13:27:08 +0200 | From | Pavel Machek <> | Subject | Re: rowhammer protection [was Re: Getting interrupt every million cache misses] |
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Hi!
> > I agree this needs to be tunable (and with the other suggestions). But > > this is actually not the most important tunable: the detection > > threshold (rh_attr.sample_period) should be way more important. > > So being totally ignorant of the detail of how rowhammer abuses the DDR > thing, would it make sense to trigger more often and delay shorter? Or > is there some minimal delay required for things to settle or > something.
We can trigger more often and delay shorter, but it will mean that protection will trigger with more false positives. I guess I'll play with constants too see how big the effect is.
BTW...
[ 6267.180092] INFO: NMI handler (perf_event_nmi_handler) took too long to run: 63.501 msecs
but I'm doing mdelay(64). .5 msec is not big difference, but...
Best regards, Pavel
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