On Tue, Apr 06, 2021 at 09:57:03PM +0200, Oscar Salvador wrote:
> On Tue, Apr 06, 2021 at 11:39:47AM -0700, Randy Dunlap wrote:
>
> > > Looks like that compound "if" is too much for gcc 7.5.0 to handle:
> > >
> > > } else if (IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP) &&
> > > vmemmap_pmd_is_unused(addr, next)) {
> > > free_hugepage_table(pmd_page(*pmd),
> > > altmap);
> > > spin_lock(&init_mm.page_table_lock);
> > > pmd_clear(pmd);
> > > spin_unlock(&init_mm.page_table_lock);
> > > }
> > >
> > >
> >
> > This is what I am using for now:
>
> Hi Randy
>
> Yeah, that is what v4 was using [1].
> We decided to get rid of the ifdef for costimetic reasons but it seems
> it does not do the trick.
>
> I will ask Andrew to squash that on top.
This is pretty ugly. What I was doing was this:
+++ b/arch/x86/mm/init_64.c
@@ -862,6 +862,9 @@ static bool __meminit vmemmap_pmd_is_unused(unsigned long addr, unsigned long en
return !memchr_inv((void *)start, PAGE_UNUSED, PMD_SIZE);
}
+#else
+static inline bool vmemmap_pmd_is_unused(unsigned long addr, unsigned long end)
+{ return false; }
#endif
static void __meminit __vmemmap_use_sub_pmd(unsigned long start)
@@ -924,6 +927,9 @@ static void __meminit vmemmap_use_new_sub_pmd(unsigned long start, unsigned long
if (!IS_ALIGNED(end, PMD_SIZE))
unused_pmd_start = end;
}
+#else
+static inline bool vmemmap_pmd_is_unused(unsigned long addr, unsigned long end)
+{ return false; }
#endif
/*
(whitespace damaged, but ...)
