Re: Privilege Levels Below User

On Tue, 11 Jun 2024 08:54:16 +0300, Niklas Holsti
<niklas.holsti@tidorum.invalid> wrote:

Not always. If the mistakenly speculated cache-fetch /evicted/ some
other data from the (finite-sized) cache, and the evicted data are
needed later on the /true/ execution path, the mistakenly speculated
fetch has a /negative/ effect on performance. (This kind of "timing
anomaly" is very bothersome in static WCET analysis.)

Ouch. Another argument for having a victim cache. And a benefit of
doing it in what is apparently Mitch Alsup's way - holding off cache
updates until instruction retirement.

John Savard