* Linus Torvalds <[email protected]> wrote:
> On Tue, May 7, 2019 at 6:26 AM Borislav Petkov <[email protected]> wrote: > > > > This branch contains work started by Rik van Riel and brought to > > fruition by Sebastian Andrzej Siewior with the main goal to optimize > > when to load FPU registers: only when returning to userspace and not > > on every context switch (while the task remains in the kernel). > > I love this and we should have done it long ago, but I also worry that > every time we've messed with the FP state, we've had interesting bugs. > Which is obviously why we didn't do this long ago. > > Has this gone through lots of testing, particularly with things like FP > signal handling and old machines that don't necessarily have anything > but the most basic FP state (ie Pentium class etc)? > > I've pulled it, but I'd still like to feel safer about it > after-the-fact ;) Most of the x86/fpu commits except the final one are several weeks old, but I have to admit that our old-systems testing is hit and miss, and FPU bugs do tend to have an additional 'bug report latency' multipier of a factor of 3 or so ... I've been running all this (modulo the final commit) on my primary desktop and other systems as well, FWIIW. Thanks, Ingo
