On 1/13/2018 8:07 AM, Van De Ven, Arjan wrote: >>> 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 <[email protected]> >> >> Conditionally-Acked-by: David Woodhouse <[email protected]> > > > 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?
That should work on AMD. Thanks, Tom > >
