Make size of the linear map to be allocated in RMA region to be of
ppc64_rma_size / 4. If debug_pagealloc requires more memory than that
then do not allocate any memory and disable debug_pagealloc.
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
---
arch/powerpc/mm/book3s64/hash_utils.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index 11975a2f7403..f51f2cd9bf22 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -331,9 +331,19 @@ static unsigned long linear_map_hash_count;
static DEFINE_RAW_SPINLOCK(linear_map_hash_lock);
static inline void hash_debug_pagealloc_alloc_slots(void)
{
+ unsigned long max_hash_count = ppc64_rma_size / 4;
+
if (!debug_pagealloc_enabled())
return;
linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT;
+ if (unlikely(linear_map_hash_count > max_hash_count)) {
+ pr_info("linear map size (%llu) greater than 4 times RMA region (%llu). Disabling debug_pagealloc\n",
+ ((u64)linear_map_hash_count << PAGE_SHIFT),
+ ppc64_rma_size);
+ linear_map_hash_count = 0;
+ return;
+ }
+
linear_map_hash_slots = memblock_alloc_try_nid(
linear_map_hash_count, 1, MEMBLOCK_LOW_LIMIT,
ppc64_rma_size, NUMA_NO_NODE);
@@ -344,7 +354,7 @@ static inline void hash_debug_pagealloc_alloc_slots(void)
static inline void hash_debug_pagealloc_add_slot(phys_addr_t paddr, int slot)
{
- if (!debug_pagealloc_enabled())
+ if (!debug_pagealloc_enabled() || !linear_map_hash_count)
return;
if ((paddr >> PAGE_SHIFT) < linear_map_hash_count)
linear_map_hash_slots[paddr >> PAGE_SHIFT] = slot | 0x80;
@@ -356,6 +366,9 @@ static int hash_debug_pagealloc_map_pages(struct page *page, int numpages,
unsigned long flags, vaddr, lmi;
int i;
+ if (!debug_pagealloc_enabled() || !linear_map_hash_count)
+ return 0;
+
local_irq_save(flags);
for (i = 0; i < numpages; i++, page++) {
vaddr = (unsigned long)page_address(page);
--
2.46.0
