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* [PATCH] mm/migrate: fix NR_ISOLATED corruption on 64-bit
@ 2021-07-28  4:25 Aneesh Kumar K.V
  2021-07-28  8:19 ` David Hildenbrand
  2021-07-28 23:44 ` Yang Shi
  0 siblings, 2 replies; 3+ messages in thread
From: Aneesh Kumar K.V @ 2021-07-28  4:25 UTC (permalink / raw)
  To: linux-mm; +Cc: akpm, Aneesh Kumar K.V, Yang Shi, Michael Ellerman

Similar to commit 2da9f6305f30 ("mm/vmscan: fix NR_ISOLATED_FILE corruption on 64-bit")
avoid using unsigned int for nr_pages. With unsigned int type the large
unsigned int converts to a large positive signed long.

Symptoms include CMA allocations hanging forever
due to alloc_contig_range->...->isolate_migratepages_block waiting
forever in "while (unlikely(too_many_isolated(pgdat)))".

Fixes: c5fc5c3ae0c8 ("mm: migrate: account THP NUMA migration counters correctly")
Cc: Yang Shi <shy828301@gmail.com>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 mm/migrate.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 34a9ad3e0a4f..7e240437e7d9 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2068,7 +2068,7 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
 	LIST_HEAD(migratepages);
 	new_page_t *new;
 	bool compound;
-	unsigned int nr_pages = thp_nr_pages(page);
+	int nr_pages = thp_nr_pages(page);
 
 	/*
 	 * PTE mapped THP or HugeTLB page can't reach here so the page could
-- 
2.31.1



^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] mm/migrate: fix NR_ISOLATED corruption on 64-bit
  2021-07-28  4:25 [PATCH] mm/migrate: fix NR_ISOLATED corruption on 64-bit Aneesh Kumar K.V
@ 2021-07-28  8:19 ` David Hildenbrand
  2021-07-28 23:44 ` Yang Shi
  1 sibling, 0 replies; 3+ messages in thread
From: David Hildenbrand @ 2021-07-28  8:19 UTC (permalink / raw)
  To: Aneesh Kumar K.V, linux-mm
  Cc: akpm, Yang Shi, Michael Ellerman, Nicholas Piggin

On 28.07.21 06:25, Aneesh Kumar K.V wrote:
> Similar to commit 2da9f6305f30 ("mm/vmscan: fix NR_ISOLATED_FILE corruption on 64-bit")
> avoid using unsigned int for nr_pages. With unsigned int type the large
> unsigned int converts to a large positive signed long.
> 
> Symptoms include CMA allocations hanging forever
> due to alloc_contig_range->...->isolate_migratepages_block waiting
> forever in "while (unlikely(too_many_isolated(pgdat)))".
> 
> Fixes: c5fc5c3ae0c8 ("mm: migrate: account THP NUMA migration counters correctly")
> Cc: Yang Shi <shy828301@gmail.com>
> Reported-by: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> ---
>   mm/migrate.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 34a9ad3e0a4f..7e240437e7d9 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -2068,7 +2068,7 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
>   	LIST_HEAD(migratepages);
>   	new_page_t *new;
>   	bool compound;
> -	unsigned int nr_pages = thp_nr_pages(page);
> +	int nr_pages = thp_nr_pages(page);
>   
>   	/*
>   	 * PTE mapped THP or HugeTLB page can't reach here so the page could
> 


Already posted:

https://lkml.kernel.org/r/20210722054840.501423-1-npiggin@gmail.com

but this patch description is a lot better.


-- 
Thanks,

David / dhildenb



^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] mm/migrate: fix NR_ISOLATED corruption on 64-bit
  2021-07-28  4:25 [PATCH] mm/migrate: fix NR_ISOLATED corruption on 64-bit Aneesh Kumar K.V
  2021-07-28  8:19 ` David Hildenbrand
@ 2021-07-28 23:44 ` Yang Shi
  1 sibling, 0 replies; 3+ messages in thread
From: Yang Shi @ 2021-07-28 23:44 UTC (permalink / raw)
  To: Aneesh Kumar K.V; +Cc: Linux MM, Andrew Morton, Michael Ellerman

On Tue, Jul 27, 2021 at 9:25 PM Aneesh Kumar K.V
<aneesh.kumar@linux.ibm.com> wrote:
>
> Similar to commit 2da9f6305f30 ("mm/vmscan: fix NR_ISOLATED_FILE corruption on 64-bit")
> avoid using unsigned int for nr_pages. With unsigned int type the large
> unsigned int converts to a large positive signed long.
>
> Symptoms include CMA allocations hanging forever
> due to alloc_contig_range->...->isolate_migratepages_block waiting
> forever in "while (unlikely(too_many_isolated(pgdat)))".
>
> Fixes: c5fc5c3ae0c8 ("mm: migrate: account THP NUMA migration counters correctly")
> Cc: Yang Shi <shy828301@gmail.com>
> Reported-by: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>

It seems Andrew picked this one. Either one is fine to me.
Reviewed-by: Yang Shi <shy828301@gmail.com>

> ---
>  mm/migrate.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 34a9ad3e0a4f..7e240437e7d9 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -2068,7 +2068,7 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
>         LIST_HEAD(migratepages);
>         new_page_t *new;
>         bool compound;
> -       unsigned int nr_pages = thp_nr_pages(page);
> +       int nr_pages = thp_nr_pages(page);
>
>         /*
>          * PTE mapped THP or HugeTLB page can't reach here so the page could
> --
> 2.31.1
>


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-07-28 23:44 UTC | newest]

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2021-07-28  4:25 [PATCH] mm/migrate: fix NR_ISOLATED corruption on 64-bit Aneesh Kumar K.V
2021-07-28  8:19 ` David Hildenbrand
2021-07-28 23:44 ` Yang Shi

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