2019-05-07 18:40:51

by David Hildenbrand

Subject: [PATCH v2 1/8] mm/memory_hotplug: Simplify and fix check_hotplug_memory_range()

By converting start and size to page granularity, we actually ignore
unaligned parts within a page instead of properly bailing out with an
error.

Cc: Andrew Morton <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: Qian Cai <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Arun KS <[email protected]>
Cc: Mathieu Malaterre <[email protected]>
Signed-off-by: David Hildenbrand <[email protected]>
---
mm/memory_hotplug.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 328878b6799d..202febe88b58 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1050,16 +1050,11 @@ int try_online_node(int nid)

static int check_hotplug_memory_range(u64 start, u64 size)
{
- unsigned long block_sz = memory_block_size_bytes();
- u64 block_nr_pages = block_sz >> PAGE_SHIFT;
- u64 nr_pages = size >> PAGE_SHIFT;
- u64 start_pfn = PFN_DOWN(start);
-
/* memory range must be block size aligned */
- if (!nr_pages || !IS_ALIGNED(start_pfn, block_nr_pages) ||
- !IS_ALIGNED(nr_pages, block_nr_pages)) {
+ if (!size || !IS_ALIGNED(start, memory_block_size_bytes()) ||
+ !IS_ALIGNED(size, memory_block_size_bytes())) {
pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx",
- block_sz, start, size);
+ memory_block_size_bytes(), start, size);
return -EINVAL;
}

--
2.20.1

2019-05-07 20:40:09

by Dan Williams

Subject: Re: [PATCH v2 1/8] mm/memory_hotplug: Simplify and fix check_hotplug_memory_range()

On Tue, May 7, 2019 at 11:38 AM David Hildenbrand <[email protected]> wrote:
>
> By converting start and size to page granularity, we actually ignore
> unaligned parts within a page instead of properly bailing out with an
> error.
>
> Cc: Andrew Morton <[email protected]>
> Cc: Oscar Salvador <[email protected]>
> Cc: Michal Hocko <[email protected]>
> Cc: David Hildenbrand <[email protected]>
> Cc: Pavel Tatashin <[email protected]>
> Cc: Qian Cai <[email protected]>
> Cc: Wei Yang <[email protected]>
> Cc: Arun KS <[email protected]>
> Cc: Mathieu Malaterre <[email protected]>
> Signed-off-by: David Hildenbrand <[email protected]>

Reviewed-by: Dan Williams <[email protected]>

2019-05-09 12:24:43

by Wei Yang

Subject: Re: [PATCH v2 1/8] mm/memory_hotplug: Simplify and fix check_hotplug_memory_range()

On Tue, May 07, 2019 at 08:37:57PM +0200, David Hildenbrand wrote:
>By converting start and size to page granularity, we actually ignore
>unaligned parts within a page instead of properly bailing out with an
>error.
>
>Cc: Andrew Morton <[email protected]>
>Cc: Oscar Salvador <[email protected]>
>Cc: Michal Hocko <[email protected]>
>Cc: David Hildenbrand <[email protected]>
>Cc: Pavel Tatashin <[email protected]>
>Cc: Qian Cai <[email protected]>
>Cc: Wei Yang <[email protected]>
>Cc: Arun KS <[email protected]>
>Cc: Mathieu Malaterre <[email protected]>
>Signed-off-by: David Hildenbrand <[email protected]>

Reviewed-by: Wei Yang <[email protected]>


--
Wei Yang
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