> -----Original Message-----
> From: Intel-wired-lan <[email protected]> On Behalf
> Of Arnd Bergmann
> Sent: Friday, June 20, 2025 7:31 PM
> To: Nguyen, Anthony L <[email protected]>; Kitszel,
> Przemyslaw <[email protected]>; Andrew Lunn
> <[email protected]>; David S. Miller <[email protected]>; Eric
> Dumazet <[email protected]>; Jakub Kicinski <[email protected]>; Paolo
> Abeni <[email protected]>
> Cc: Arnd Bergmann <[email protected]>; Simon Horman <[email protected]>;
> Dr. David Alan Gilbert <[email protected]>; Loktionov, Aleksandr
> <[email protected]>; Dawid Osuchowski
> <[email protected]>; Jagielski, Jedrzej
> <[email protected]>; Polchlopek, Mateusz
> <[email protected]>; Kwapulinski, Piotr
> <[email protected]>; Mrozowicz, SlawomirX
> <[email protected]>; Martyna Szapar-Mudlaw
> <[email protected]>; intel-wired-
> [email protected]; [email protected]; linux-
> [email protected]
> Subject: [Intel-wired-lan] [PATCH] [v2] ethernet: intel: fix building
> with large NR_CPUS
>
> From: Arnd Bergmann <[email protected]>
>
> With large values of CONFIG_NR_CPUS, three Intel ethernet drivers fail
> to compile like:
>
> In function ‘i40e_free_q_vector’,
> inlined from ‘i40e_vsi_alloc_q_vectors’ at
> drivers/net/ethernet/intel/i40e/i40e_main.c:12112:3:
> 571 | _compiletime_assert(condition, msg,
> __compiletime_assert_, __COUNTER__)
> include/linux/rcupdate.h:1084:17: note: in expansion of macro
> ‘BUILD_BUG_ON’
> 1084 | BUILD_BUG_ON(offsetof(typeof(*(ptr)), rhf) >=
> 4096); \
> drivers/net/ethernet/intel/i40e/i40e_main.c:5113:9: note: in expansion
> of macro ‘kfree_rcu’
> 5113 | kfree_rcu(q_vector, rcu);
> | ^~~~~~~~~
>
> The problem is that the 'rcu' member in 'q_vector' is too far from the
> start of the structure. Move this member before the CPU mask instead,
> in all three drivers.
>
> Signed-off-by: Arnd Bergmann <[email protected]>
Reviewed-by: Aleksandr Loktionov <[email protected]>
> ---
> v2: move rcu to just after the napi_struct [Alexander Lobakin]
> ---
> drivers/net/ethernet/intel/fm10k/fm10k.h | 3 ++-
> drivers/net/ethernet/intel/i40e/i40e.h | 2 +-
> drivers/net/ethernet/intel/ixgbe/ixgbe.h | 3 ++-
> 3 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/fm10k/fm10k.h
> b/drivers/net/ethernet/intel/fm10k/fm10k.h
> index 6119a4108838..65a2816142d9 100644
> --- a/drivers/net/ethernet/intel/fm10k/fm10k.h
> +++ b/drivers/net/ethernet/intel/fm10k/fm10k.h
> @@ -189,13 +189,14 @@ struct fm10k_q_vector {
> struct fm10k_ring_container rx, tx;
>
> struct napi_struct napi;
> + struct rcu_head rcu; /* to avoid race with update stats on free
> */
> +
> cpumask_t affinity_mask;
> char name[IFNAMSIZ + 9];
>
> #ifdef CONFIG_DEBUG_FS
> struct dentry *dbg_q_vector;
> #endif /* CONFIG_DEBUG_FS */
> - struct rcu_head rcu; /* to avoid race with update stats on free
> */
>
> /* for dynamic allocation of rings associated with this
> q_vector */
> struct fm10k_ring ring[] ____cacheline_internodealigned_in_smp;
> diff --git a/drivers/net/ethernet/intel/i40e/i40e.h
> b/drivers/net/ethernet/intel/i40e/i40e.h
> index 54d5fdc303ca..c429252859d3 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e.h
> +++ b/drivers/net/ethernet/intel/i40e/i40e.h
> @@ -946,6 +946,7 @@ struct i40e_q_vector {
> u16 reg_idx; /* register index of the interrupt */
>
> struct napi_struct napi;
> + struct rcu_head rcu; /* to avoid race with update stats on free
> */
>
> struct i40e_ring_container rx;
> struct i40e_ring_container tx;
> @@ -956,7 +957,6 @@ struct i40e_q_vector {
> cpumask_t affinity_mask;
> struct irq_affinity_notify affinity_notify;
>
> - struct rcu_head rcu; /* to avoid race with update stats on free
> */
> char name[I40E_INT_NAME_STR_LEN];
> bool arm_wb_state;
> bool in_busy_poll;
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h
> b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
> index c6772cd2d802..3f9521d4e899 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
> @@ -507,9 +507,10 @@ struct ixgbe_q_vector {
> struct ixgbe_ring_container rx, tx;
>
> struct napi_struct napi;
> + struct rcu_head rcu; /* to avoid race with update stats on free
> */
> +
> cpumask_t affinity_mask;
> int numa_node;
> - struct rcu_head rcu; /* to avoid race with update stats on free
> */
> char name[IFNAMSIZ + 9];
>
> /* for dynamic allocation of rings associated with this
> q_vector */
> --
> 2.39.5
