On Mon, Nov 13, 2023 at 12:36:04PM -0500, H. Peter Anvin wrote: > A resource cannot be consumed after the value has been written; this > is the only necessary level of serialization, equivalent to, say, RAX. Lemme see if I understand this correctly using this context as an example: after this MSR_IA32_FRED_RSP0 write, any FRED events determined to be delivered to level 0 will use this new task stack ptr? And since the new task is not running yet and the old one isn't running either, we're fine here. So the "serialization point" I was talking about above is bollocks. Close? :) > A serializing instruction stops the entire pipeline until everything > has retired and any stores have become globally visible. Right, we don't need that here. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette