I'm not that old, but I've been closely following these trends since the late 1990s, and it seems to me like we are descending into madness now. We are wiping out years of single-core performance gains--which have been hard to come by over the last decade to begin with--through all of these mitigations. It seems to me like maybe the mental model is broken. If untrusted code is running on the same core/package/what have you, your security has already been breached.
> This flushing does address CVE-2020-0550 for snoop-assisted L1 data sampling but the main emphasis seems to be on the "yet to be discovered vulnerabilities."<p>I am unsure if this is just idle speculation (heh) that there may be issues in this area or there are issues that have been disclosed to vendors but not the public yet?
Last week Microsoft also rereleased the Intel microcode updates package [1][2]. I kinda expect to see a new CPU flaw in the next few days.<p>[1]<a href="https://support.microsoft.com/en-us/help/4497165/kb4497165-intel-microcode-updates" rel="nofollow">https://support.microsoft.com/en-us/help/4497165/kb4497165-i...</a><p>[2]<a href="https://www.windowslatest.com/2020/05/21/windows-10-kb4497165-update-released/" rel="nofollow">https://www.windowslatest.com/2020/05/21/windows-10-kb449716...</a>
So with more cores and associated L1 cache, context switching would be potentially less I would of thought, small but maybe measurable.<p>Interestingly enough: <a href="https://www.theregister.co.uk/2020/05/24/linus_torvalds_adopts_amd_threadripper/" rel="nofollow">https://www.theregister.co.uk/2020/05/24/linus_torvalds_adop...</a>
Maybe time to redo the ring model with multi core cpu's now the norm.<p>Why one or two CPU cores couldn't be dedicated to the OS aspect and locked out of user-space of any form, certainly would be something worth exploring.