[PATCH] dma-buf: system_heap: account for system heap allocation in memcg

From: Eric Chanudet

Date: Thu Dec 11 2025 - 14:31:51 EST


The system dma-buf heap lets userspace allocate buffers from the page
allocator. However, these allocations are not accounted for in memcg,
allowing processes to escape limits that may be configured.

Pass the __GFP_ACCOUNT for our allocations to account them into memcg.

Userspace components using the system heap can be constrained with, e.g:
systemd-run --user --scope -p MemoryMax=10M ...

Signed-off-by: Eric Chanudet <echanude@xxxxxxxxxx>
---
drivers/dma-buf/heaps/system_heap.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
index 4c782fe33fd4..c91fcdff4b77 100644
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -38,10 +38,10 @@ struct dma_heap_attachment {
bool mapped;
};

-#define LOW_ORDER_GFP (GFP_HIGHUSER | __GFP_ZERO)
+#define LOW_ORDER_GFP (GFP_HIGHUSER | __GFP_ZERO | __GFP_ACCOUNT)
#define HIGH_ORDER_GFP (((GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN \
| __GFP_NORETRY) & ~__GFP_RECLAIM) \
- | __GFP_COMP)
+ | __GFP_COMP | __GFP_ACCOUNT)
static gfp_t order_flags[] = {HIGH_ORDER_GFP, HIGH_ORDER_GFP, LOW_ORDER_GFP};
/*
* The selection of the orders used for allocation (1MB, 64K, 4K) is designed
--
2.52.0