On Wed, 2018-01-03 at 18:13 -0700, stan wrote: > On Wed, 03 Jan 2018 15:02:11 -0800 > Adam Williamson <adamwill@xxxxxxxxxxxxxxxxx> wrote: > > > * We know that the fix can lead to reduced performance in some cases > > (this affects synthetic benchmarks rather more than real-world > > performance). The kernel team thinks the fix is sufficiently important > > that it should go out despite the performance impact. Accordingly, > > please do not file negative karma for this reason. If the update > > somehow results in such a significant performance impact that the > > system becomes unusable, though, please report that. > > From my reading about the problem on the web, the fix always has a > degrading effect on performance, since the page table can no longer be > kept in the program memory space, so has to be reloaded every time a > system call is made. Sorry, imprecise language. I didn't mean "in some cases" in the sense that some systems would not be subject to slowdowns at all. I meant that the performance impact is only noticeable with some workloads. > > > * The fix is currently applied only to x86_64 kernels. No fix is yet > > present for any other architecture, but of course all architectures > > are rebuilt for the update. > > Again, from my reading on the web this only affects Intel CPUs of the > last decade. This is certainly not correct. Both the Google researchers and Red Hat's security team have stated that many other CPUs and CPU families are affected. ARM has already released a statement acknowledging that several of their CPUs, including ones very widely used in smartphones etc., are affected. The initial reporting that only Intel CPUs were affected was entirely wrong. -- Adam Williamson Fedora QA Community Monkey IRC: adamw | Twitter: AdamW_Fedora | XMPP: adamw AT happyassassin . net http://www.happyassassin.net _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx
