On Thu, Dec 8, 2016 at 8:21 AM, Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> wrote: > This basically restores slightly modified version of original > sync_global_pgds() which we had before foldedl p4d was introduced. > > The only modification is protection against 'address' overflow. > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > --- > arch/x86/mm/init_64.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 47 insertions(+) > > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index a991f5c4c2c4..d637893ac8c2 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -92,6 +92,52 @@ __setup("noexec32=", nonx32_setup); > * When memory was added/removed make sure all the processes MM have > * suitable PGD entries in the local PGD level page. > */ > +#ifdef CONFIG_X86_5LEVEL > +void sync_global_pgds(unsigned long start, unsigned long end, int removed) > +{ > + unsigned long address; > + > + for (address = start; address <= end && address >= start; > + address += PGDIR_SIZE) { > + const pgd_t *pgd_ref = pgd_offset_k(address); > + struct page *page; > + > + /* > + * When it is called after memory hot remove, pgd_none() > + * returns true. In this case (removed == 1), we must clear > + * the PGD entries in the local PGD level page. > + */ > + if (pgd_none(*pgd_ref) && !removed) > + continue; This isn't quite specific to your patch, but can we assert that, if removed=1, then we're not operating on the vmalloc range? Because if we do, this will be racy is nasty ways. -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html