On Thu, Mar 13, 2025 at 05:07:59PM +0200, Mike Rapoport wrote:
>Hi Wei,
>
>On Wed, Mar 12, 2025 at 01:07:27PM +0000, Wei Yang wrote:
>> Commit 61167ad5fecd ("mm: pass nid to reserve_bootmem_region()") introduce
>> a way to set nid to all reserved region.
>>
>> But there is a corner case it will leave some region with invalid nid.
>> When memblock_set_node() doubles the array of memblock.reserved, it may
>> lead to a new reserved region before current position. The new region
>> will be left with an invalid node id.
>>
>> Repeat the process when detecting it.
>>
>> Fixes: 61167ad5fecd ("mm: pass nid to reserve_bootmem_region()")
>> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
>> CC: Mike Rapoport <rppt@xxxxxxxxxx>
>> CC: Yajun Deng <yajun.deng@xxxxxxxxx>
>> CC: <stable@xxxxxxxxxxxxxxx>
>> ---
>> mm/memblock.c | 12 ++++++++++++
>> 1 file changed, 12 insertions(+)
>>
>> diff --git a/mm/memblock.c b/mm/memblock.c
>> index 85442f1b7f14..302dd7bc622d 100644
>> --- a/mm/memblock.c
>> +++ b/mm/memblock.c
>> @@ -2184,7 +2184,10 @@ static void __init memmap_init_reserved_pages(void)
>> * set nid on all reserved pages and also treat struct
>> * pages for the NOMAP regions as PageReserved
>> */
>> +repeat:
>> for_each_mem_region(region) {
>> + unsigned long max = memblock.reserved.max;
>> +
>> nid = memblock_get_region_node(region);
>> start = region->base;
>> end = start + region->size;
>> @@ -2193,6 +2196,15 @@ static void __init memmap_init_reserved_pages(void)
>> reserve_bootmem_region(start, end, nid);
>>
>> memblock_set_node(start, region->size, &memblock.reserved, nid);
>> +
>> + /*
>> + * 'max' is changed means memblock.reserved has been doubled
>> + * its array, which may result a new reserved region before
>> + * current 'start'. Now we should repeat the procedure to set
>> + * its node id.
>> + */
>> + if (max != memblock.reserved.max)
>> + goto repeat;
>
>This check can be moved outside the loop, can't it?
>
We can. You mean something like this?
diff --git a/mm/memblock.c b/mm/memblock.c
index 85442f1b7f14..67fd1695cce4 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -2179,11 +2179,14 @@ static void __init memmap_init_reserved_pages(void)
struct memblock_region *region;
phys_addr_t start, end;
int nid;
+ unsigned long max;
/*
* set nid on all reserved pages and also treat struct
* pages for the NOMAP regions as PageReserved
*/
+repeat:
+ max = memblock.reserved.max;
for_each_mem_region(region) {
nid = memblock_get_region_node(region);
start = region->base;
@@ -2194,6 +2197,13 @@ static void __init memmap_init_reserved_pages(void)
memblock_set_node(start, region->size, &memblock.reserved, nid);
}
+ /*
+ * 'max' is changed means memblock.reserved has been doubled its
+ * array, which may result a new reserved region before current
+ * 'start'. Now we should repeat the procedure to set its node id.
+ */
+ if (max != memblock.reserved.max)
+ goto repeat;
/*
* initialize struct pages for reserved regions that don't have
--
Wei Yang
Help you, Help me
