On Wed, Jun 07, 2017 at 08:03:25PM +0300, Kirill A. Shutemov wrote: > On Wed, Jun 07, 2017 at 10:46:20AM -0400, [email protected] wrote: > > From: Jérôme Glisse <[email protected]> > > > > With commit af2cf278ef4f we no longer free pud so that we do not > > have synchronize all pgd on hotremove/vfree. But the new 5 level > > page table patchset reverted that for 4 level page table. > > > > This patch restore af2cf278ef4f and disable free_pud() if we are > > in the 4 level page table case thus avoiding BUG_ON() after hot- > > remove. > > > > af2cf278ef4f x86/mm/hotplug: Don't remove PGD entries in remove_pagetable() > > > > Changed since v1: > > - make free_pud() conditional on the number of page table > > level > > - improved commit message > > > > Signed-off-by: Jérôme Glisse <[email protected]> > > Cc: Andy Lutomirski <[email protected]> > > Cc: Ingo Molnar <[email protected]> > > Cc: Kirill A. Shutemov <[email protected]> > > Cc: Logan Gunthorpe <[email protected]> > > > thus we now trigger a BUG_ON() l128 in sync_global_pgds() > > > > > > This patch remove free_pud() like in af2cf278ef4f > > --- > > arch/x86/mm/init_64.c | 11 +++++++++++ > > 1 file changed, 11 insertions(+) > > > > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > > index 95651dc..61028bc 100644 > > --- a/arch/x86/mm/init_64.c > > +++ b/arch/x86/mm/init_64.c > > @@ -771,6 +771,16 @@ static void __meminit free_pmd_table(pmd_t *pmd_start, > > pud_t *pud) > > spin_unlock(&init_mm.page_table_lock); > > } > > > > +/* > > + * For 4 levels page table we do not want to free puds but for 5 levels > > + * we should free them. This code also need to change to adapt for boot > > + * time switching between 4 and 5 level. > > + */ > > +#if CONFIG_PGTABLE_LEVELS == 4 > > +static inline void free_pud_table(pud_t *pud_start, p4d_t *p4d) > > +{ > > +} > > Just "if (CONFIG_PGTABLE_LEVELS > 4)" before calling free_pud_table(), but > okay -- I'll rework it anyway for boot-time switching.
Err. "if (CONFIG_PGTABLE_LEVELS == 4)" obviously. -- Kirill A. Shutemov
