Messages in this thread | | | From | Logan Gunthorpe <> | Date | Wed, 7 Jun 2017 10:14:58 -0600 | Subject | Re: [PATCH] x86/mm/hotplug: fix BUG_ON() after hotremove by not freeing pud v2 |
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This patch still fixes my bug.
Tested-by: Logan Gunthorpe <logang@deltatee.com>
Thanks,
Logan
On 07/06/17 08:46 AM, jglisse@redhat.com wrote: > From: Jérôme Glisse <jglisse@redhat.com> > > 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 <jglisse@redhat.com> > Cc: Andy Lutomirski <luto@kernel.org> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Cc: Logan Gunthorpe <logang@deltatee.com> >> 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) > +{ > +} > +#else /* CONFIG_PGTABLE_LEVELS == 4 */ > static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d) > { > pud_t *pud; > @@ -788,6 +798,7 @@ static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d) > p4d_clear(p4d); > spin_unlock(&init_mm.page_table_lock); > } > +#endif /* CONFIG_PGTABLE_LEVELS == 4 */ > > static void __meminit > remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end, >
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