On Fri, 2018-04-27 at 08:28 +0200, Ingo Molnar wrote: > * Kani, Toshi <toshi.kani@xxxxxxx> wrote: > > > On Thu, 2018-04-26 at 17:14 +0200, Joerg Roedel wrote: > > > From: Joerg Roedel <jroedel@xxxxxxx> > > > > > > This reverts commit 28ee90fe6048fa7b7ceaeb8831c0e4e454a4cf89. > > > > > > This commit is broken for x86, as it unmaps the PTE and PMD > > > pages and immediatly frees them without doing a TLB flush. > > > > > > Further this lacks synchronization with other page-tables in > > > the system when the PMD pages are not shared between > > > mm_structs. > > > > > > On x86-32 with PAE and PTI patches on-top this patch > > > triggers the BUG_ON in vmalloc_sync_one() because the kernel > > > and the process page-table were not synchronized. > > > > > > Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> > > > > I do not agree with the comments and this revert. Let's discuss further > > on the original thread. > > The original patch is totally broken (it's based on a misunderstanding), so unless > you have a fix the revert is justified. I am working on a fix on top of this patch. Thanks, -Toshi