On Sat, 2018-04-28 at 11:02 +0200, joro@xxxxxxxxxx wrote: > On Fri, Apr 27, 2018 at 02:31:51PM +0000, Kani, Toshi wrote: > > So, we can add the step 2 on top of this patch. > > 1. Clear pud/pmd entry. > > 2. System wide TLB flush <-- TO BE ADDED BY NEW PATCH > > 3. Free its underlining pmd/pte page. > > This still lacks the page-table synchronization and will thus not fix > the BUG_ON being triggered. The BUG_ON issue is specific to PAE that it syncs at the pmd level. x86/64 does not have this issue since it syncs at the pgd or p4d level. > > We do not need to revert this patch. We can make the above change I > > mentioned. > > Please note that we are not in the merge window anymore and that any fix > needs to be simple and obviously correct. Understood. Changing the x86/32 sync point is risky. So, I am going to revert the free page handling for PAE. Thanks, -Toshi