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author | Gerald Schaefer <gerald.schaefer@de.ibm.com> | 2012-02-24 21:01:29 +0400 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2012-02-24 21:01:36 +0400 |
commit | 892365ab4d29ed861709ee8611b53587ca2bb75f (patch) | |
tree | e66d38b909ee69025d996a37cb27e2f1ad8c4210 /arch/s390 | |
parent | d60331ac0d961ae063e69c43f09d14244ad5d921 (diff) | |
download | linux-892365ab4d29ed861709ee8611b53587ca2bb75f.tar.xz |
[S390] memory hotplug: prevent memory zone interleave
This fixes a kernel oops with CONFIG_DEBUG_VM triggered by a
VM_BUG_ON(bad_range()): kernel BUG at mm/page_alloc.c:748.
With memory hotplug on System z, it is possible that the memory
online/offline state is preserved over a system restart, e.g. there
may be offline memory blocks in ZONE_DMA or ZONE_NORMAL. So far,
the offline memory range has always been added to ZONE_MOVABLE during
system start, so that it was possible to have ZONE_MOVABLE interleave
with ZONE_DMA or ZONE_NORMAL. This patch fixes that by checking for
zone overlap before adding memory.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r-- | arch/s390/mm/init.c | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index 5d633019d8f3..50236610de83 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -223,16 +223,38 @@ void free_initrd_mem(unsigned long start, unsigned long end) #ifdef CONFIG_MEMORY_HOTPLUG int arch_add_memory(int nid, u64 start, u64 size) { - struct pglist_data *pgdat; + unsigned long zone_start_pfn, zone_end_pfn, nr_pages; + unsigned long start_pfn = PFN_DOWN(start); + unsigned long size_pages = PFN_DOWN(size); struct zone *zone; int rc; - pgdat = NODE_DATA(nid); - zone = pgdat->node_zones + ZONE_MOVABLE; rc = vmem_add_mapping(start, size); if (rc) return rc; - rc = __add_pages(nid, zone, PFN_DOWN(start), PFN_DOWN(size)); + for_each_zone(zone) { + if (zone_idx(zone) != ZONE_MOVABLE) { + /* Add range within existing zone limits */ + zone_start_pfn = zone->zone_start_pfn; + zone_end_pfn = zone->zone_start_pfn + + zone->spanned_pages; + } else { + /* Add remaining range to ZONE_MOVABLE */ + zone_start_pfn = start_pfn; + zone_end_pfn = start_pfn + size_pages; + } + if (start_pfn < zone_start_pfn || start_pfn >= zone_end_pfn) + continue; + nr_pages = (start_pfn + size_pages > zone_end_pfn) ? + zone_end_pfn - start_pfn : size_pages; + rc = __add_pages(nid, zone, start_pfn, nr_pages); + if (rc) + break; + start_pfn += nr_pages; + size_pages -= nr_pages; + if (!size_pages) + break; + } if (rc) vmem_remove_mapping(start, size); return rc; |