[PATCH net-next v2 3/5] net: account per-CPU netdev stats to memcg

[Ali Firas]

netdev_alloc_pcpu_stats() allocates a per-CPU stats block with plain
GFP_KERNEL, so it is not charged to the cgroup of the process that
created the object it belongs to. The netdev's own queue arrays, ethtool
state and NAPI config are already allocated with GFP_KERNEL_ACCOUNT in
alloc_netdev_mqs(), which leaves the stats block allocated alongside
them as the unaccounted part of the same device.

Make the macro use GFP_KERNEL_ACCOUNT. This affects 34 call sites in 25
files; all of them already test the return value and propagate -ENOMEM,
so none of them has to be excluded. __GFP_ACCOUNT only charges an
allocation made from a task in a non-root memcg, so callers that run at
boot or from a driver probe are unaffected in practice. The devm_ and
explicit-gfp forms of the macro are left alone.

Suggested-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Assisted-by: LLM
Signed-off-by: Ali Firas <alishmery18@xxxxxxxxx>
---
v1: https://lore.kernel.org/netdev/20260909092645.3105263-1-alishmery18@xxxxxxxxx/
 include/linux/netdevice.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 1f0710eef185..7c659012355d 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3171,7 +3171,7 @@ static inline void dev_dstats_tx_dropped(struct net_device *dev)
 })
 
 #define netdev_alloc_pcpu_stats(type)					\
-	__netdev_alloc_pcpu_stats(type, GFP_KERNEL)
+	__netdev_alloc_pcpu_stats(type, GFP_KERNEL_ACCOUNT)
 
 #define devm_netdev_alloc_pcpu_stats(dev, type)				\
 ({									\
-- 
2.53.0