On Wed, Feb 14, 2018 at 11:43:42AM +0100, Pavel Machek wrote: > We have just found out that majority of 64-bit machines are broken in > rather fundamental ways (Spectre) and Intel does not even look > interested in fixing that (because it would make them look bad on > benchmarks). > > Even when the Spectre bug is mitigated... this looks like can of worms > that can not be closed. > > OTOH -- we do know that there are non-broken machines out there, > unfortunately they are mostly 32-bit :-). Removing support for > majority of working machines may not be good idea... > > [And I really hope future CPUs get at least option to treat cache miss > as a side-effect -- thus disalowed during speculation -- and probably > option to turn off speculation altogether. AFAICT, it should "only" > result in 50% slowdown -- or that was result in some riscv > presentation.] Or, future CPU designs introduce shadow caches and shadow TLBs which only speculation loads and sees and which become real only if and whend the resultant speculative calculations become real. Joe -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
