On Thu, Nov 30, 2017 at 7:40 AM, Peter Zijlstra <pet...@infradead.org> wrote: > On Mon, Nov 27, 2017 at 09:16:19PM -0800, Andy Lutomirski wrote: >> We've gotten away with having a single >> function for both this long because we've never had PCID on and >> nonglobal kernel mappings around. So we're busted starting with >> "x86/mm/kaiser: Disable global pages by default with KAISER", which >> means that we have a potential corruption issue affecting anyone who >> tries to bisect the series. >> >> Then we need to make the kernel variant do something sane (presumably >> just call __flush_tlb_all if we have PCID && !PGE). > > (We don't support PCID && !PGE) > > __flush_tlb_all() if PCID, because it needs to flush the thing from all > kernel ASIDs, which this patch -- however nasty -- achieves best. > >
Brain fart there. What I meant was: the old code was wrong if PCID was on and the page being flushed wasn't GLOBAL. Which is what KAISER dies.
