lkml.org 
[lkml]   [2016]   [Oct]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: rowhammer protection [was Re: Getting interrupt every million cache misses]
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

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2016-10-28 13:27    [W:0.142 / U:0.604 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site