The patch titled
Subject: mm/page_alloc: fix memmap_init_zone pageblock alignment
has been added to the -mm tree. Its filename is
mm-page_alloc-fix-memmap_init_zone-pageblock-alignment.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-fix-memmap_init_zone-pageblock-alignment.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-fix-memmap_init_zone-pageblock-alignment.patch
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------------------------------------------------------
From: Daniel Vacek <neelx@xxxxxxxxxx>
Subject: mm/page_alloc: fix memmap_init_zone pageblock alignment
BUG at mm/page_alloc.c:1913
> VM_BUG_ON(page_zone(start_page) != page_zone(end_page));
Commit b92df1de5d28 ("mm: page_alloc: skip over regions of invalid pfns
where possible") introduced a bug where move_freepages() triggers a
VM_BUG_ON() on uninitialized page structure due to pageblock alignment.
To fix this, simply align the skipped pfns in memmap_init_zone() the same
way as in move_freepages_block().
Link: http://lkml.kernel.org/r/1519988497-28941-1-git-send-email-neelx@xxxxxxxxxx
Fixes: b92df1de5d28 ("mm: page_alloc: skip over regions of invalid pfns where possible")
Signed-off-by: Daniel Vacek <neelx@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memblock.c | 13 ++++++-------
mm/page_alloc.c | 9 +++++++--
2 files changed, 13 insertions(+), 9 deletions(-)
diff -puN mm/memblock.c~mm-page_alloc-fix-memmap_init_zone-pageblock-alignment mm/memblock.c
--- a/mm/memblock.c~mm-page_alloc-fix-memmap_init_zone-pageblock-alignment
+++ a/mm/memblock.c
@@ -1101,13 +1101,12 @@ void __init_memblock __next_mem_pfn_rang
*out_nid = r->nid;
}
-unsigned long __init_memblock memblock_next_valid_pfn(unsigned long pfn,
- unsigned long max_pfn)
+unsigned long __init_memblock memblock_next_valid_pfn(unsigned long pfn)
{
struct memblock_type *type = &memblock.memory;
unsigned int right = type->cnt;
unsigned int mid, left = 0;
- phys_addr_t addr = PFN_PHYS(pfn + 1);
+ phys_addr_t addr = PFN_PHYS(++pfn);
do {
mid = (right + left) / 2;
@@ -1118,15 +1117,15 @@ unsigned long __init_memblock memblock_n
type->regions[mid].size))
left = mid + 1;
else {
- /* addr is within the region, so pfn + 1 is valid */
- return min(pfn + 1, max_pfn);
+ /* addr is within the region, so pfn is valid */
+ return pfn;
}
} while (left < right);
if (right == type->cnt)
- return max_pfn;
+ return -1UL;
else
- return min(PHYS_PFN(type->regions[right].base), max_pfn);
+ return PHYS_PFN(type->regions[right].base);
}
/**
diff -puN mm/page_alloc.c~mm-page_alloc-fix-memmap_init_zone-pageblock-alignment mm/page_alloc.c
--- a/mm/page_alloc.c~mm-page_alloc-fix-memmap_init_zone-pageblock-alignment
+++ a/mm/page_alloc.c
@@ -5359,9 +5359,14 @@ void __meminit memmap_init_zone(unsigned
/*
* Skip to the pfn preceding the next valid one (or
* end_pfn), such that we hit a valid pfn (or end_pfn)
- * on our next iteration of the loop.
+ * on our next iteration of the loop. Note that it needs
+ * to be pageblock aligned even when the region itself
+ * is not as move_freepages_block() can shift ahead of
+ * the valid region but still depends on correct page
+ * metadata.
*/
- pfn = memblock_next_valid_pfn(pfn, end_pfn) - 1;
+ pfn = (memblock_next_valid_pfn(pfn) &
+ ~(pageblock_nr_pages-1)) - 1;
#endif
continue;
}
_
Patches currently in -mm which might be from neelx@xxxxxxxxxx are
mm-page_alloc-fix-memmap_init_zone-pageblock-alignment.patch