Re: Privilege Levels Below User

John Savard wrote:

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.)

That is why you don't update the cache until the causing instruction retires.

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.

Change your thought from victim cache to pipeline buffer pre cache.

John Savard