> > The RSB filling macro is applicable to AMD, and, if software is unable to > > verify that lfence is serializing on AMD (possible when running under a > > hypervisor), the generic retpoline support will be used and, so, is also > > applicable to AMD. Change the use of pause to lfence. > > > > Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com> > > Conditionally-Acked-by: David Woodhouse <d...@amazon.co.uk>
pause is technically the "save me power" instruction how about a compromise where we do a double: pause lfence jmp <up> as sequence... that way if the branch recovery is fast, we get the performance of pause, but if it takes a while, on AMD you get the behavior of lfence?
