2020-10-20 07:57:41

by Richard Weinberger

[permalink] [raw]
Subject: [PATCH] um: Call pgtable_pmd_page_dtor() in __pmd_free_tlb()

Commit b2b29d6d0119 ("mm: account PMD tables like PTE tables") uncovered
a bug in uml, we forgot to call the destructor.
While we are here, give x a sane name.

Reported-by: Anton Ivanov <[email protected]>
Co-developed-by: Matthew Wilcox <[email protected]>
Signed-off-by: Richard Weinberger <[email protected]>
---
arch/um/include/asm/pgalloc.h | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/um/include/asm/pgalloc.h b/arch/um/include/asm/pgalloc.h
index 5393e13e07e0..2bbf28cf3aa9 100644
--- a/arch/um/include/asm/pgalloc.h
+++ b/arch/um/include/asm/pgalloc.h
@@ -33,7 +33,13 @@ do { \
} while (0)

#ifdef CONFIG_3_LEVEL_PGTABLES
-#define __pmd_free_tlb(tlb,x, address) tlb_remove_page((tlb),virt_to_page(x))
+
+#define __pmd_free_tlb(tlb, pmd, address) \
+do { \
+ pgtable_pmd_page_dtor(virt_to_page(pmd)); \
+ tlb_remove_page((tlb),virt_to_page(pmd)); \
+} while (0) \
+
#endif

#endif
--
2.26.2


2020-10-20 09:04:32

by Matthew Wilcox

[permalink] [raw]
Subject: Re: [PATCH] um: Call pgtable_pmd_page_dtor() in __pmd_free_tlb()

On Mon, Oct 19, 2020 at 11:10:49PM +0200, Richard Weinberger wrote:
> Commit b2b29d6d0119 ("mm: account PMD tables like PTE tables") uncovered
> a bug in uml, we forgot to call the destructor.
> While we are here, give x a sane name.
>
> Reported-by: Anton Ivanov <[email protected]>
> Co-developed-by: Matthew Wilcox <[email protected]>

Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>

> Signed-off-by: Richard Weinberger <[email protected]>

And as a bonus, $ grep PageTables /proc/meminfo
PageTables: 128720 kB

gets more accurate!

2020-10-23 16:32:40

by Christopher Obbard

[permalink] [raw]
Subject: Re: [PATCH] um: Call pgtable_pmd_page_dtor() in __pmd_free_tlb()

On Mon, Oct 19, 2020 at 11:10:49PM +0200, Richard Weinberger wrote:
> Commit b2b29d6d0119 ("mm: account PMD tables like PTE tables") uncovered
> a bug in uml, we forgot to call the destructor.
> While we are here, give x a sane name.
>
> Reported-by: Anton Ivanov <[email protected]>
> Co-developed-by: Matthew Wilcox <[email protected]>
> Signed-off-by: Richard Weinberger <[email protected]>

Tested-by: Christopher Obbard <[email protected]>