RE: [Intel-wired-lan] [PATCH] [v2] ethernet: intel: fix building with large NR_CPUS
From: Loktionov, Aleksandr <hidden>
Date: 2025-06-20 19:12:30
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From: Intel-wired-lan <redacted> On Behalf
Of Arnd Bergmann
Sent: Friday, June 20, 2025 7:31 PM
To: Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
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Subject: [Intel-wired-lan] [PATCH] [v2] ethernet: intel: fix building
with large NR_CPUS
From: Arnd Bergmann <arnd@arndb.de>
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 <arnd@arndb.de>Reviewed-by: Aleksandr Loktionov <redacted>
quoted hunk ↗ jump to hunk
--- 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.hb/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.hb/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.hb/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