From: Arnd Bergmann <arnd@kernel.org>
To: Saeed Mahameed <saeedm@nvidia.com>,
Leon Romanovsky <leon@kernel.org>,
Tariq Toukan <tariqt@nvidia.com>,
Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Eli Cohen <elic@nvidia.com>, Shay Drory <shayd@nvidia.com>,
Jacob Keller <jacob.e.keller@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>, Erez Shitrit <erezsh@nvidia.com>,
Cosmin Ratiu <cratiu@nvidia.com>,
Yevgeny Kliteynik <kliteyn@nvidia.com>,
netdev@vger.kernel.org, linux-rdma@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] [RFC] net/mlx5: don't build with CONFIG_CPUMASK_OFFSTACK
Date: Fri, 20 Jun 2025 13:10:04 +0200 [thread overview]
Message-ID: <20250620111010.3364606-1-arnd@kernel.org> (raw)
From: Arnd Bergmann <arnd@arndb.de>
Local cpumask_t variables must be wrapped with alloc_cpumask_var() or
similar helpers, to allow building with ridiculous values of CONFIG_NR_CPUS:
drivers/net/ethernet/mellanox/mlx5/core/eq.c: In function ‘comp_irq_request_sf’:
drivers/net/ethernet/mellanox/mlx5/core/eq.c:897:1: error: the frame size of 8560 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]
drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c: In function ‘mlx5_ctrl_irq_request’:
drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c:494:1: error: the frame size of 8544 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]
drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c: In function ‘mlx5_irq_request_vector’:
drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c:561:1: error: the frame size of 8560 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]
drivers/net/ethernet/mellanox/mlx5/core/irq_affinity.c: In function ‘irq_pool_request_irq’:
drivers/net/ethernet/mellanox/mlx5/core/irq_affinity.c:74:1: error: the frame size of 8544 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]
The mlx5 driver used to do this correctly in the past, but was changed
to use local 'irq_affinity_desc' structures in at least four places,
which ends up having the mask on the stack again.
It is not easily possible to use alloc_cpumask_var() again without
reverting that patch, so work around this by disallowing this drivers
on kernels that rely on CONFIG_CPUMASK_OFFSTACK.
Fixes: bbac70c74183 ("net/mlx5: Use newer affinity descriptor")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
This is probably not a great idea since most enterprise distros do
enable both CPUMASK_OFFSTACK and MLX5, and any ideas for how to sort
this out better would be helpful.
I mainly tried setting CONFIG_NR_CPUS to an unrealistic value for my
own compile testing, to see which files run into this problem. I have
managed to come up with better fixes for the other three I found, but
not this one.
---
drivers/net/ethernet/mellanox/mlx5/core/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/Kconfig b/drivers/net/ethernet/mellanox/mlx5/core/Kconfig
index 6ec7d6e0181d..7c2da240ffdb 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/Kconfig
+++ b/drivers/net/ethernet/mellanox/mlx5/core/Kconfig
@@ -8,6 +8,7 @@ config MLX5_CORE
depends on PCI
select AUXILIARY_BUS
select NET_DEVLINK
+ depends on !CPUMASK_OFFSTACK
depends on VXLAN || !VXLAN
depends on MLXFW || !MLXFW
depends on PTP_1588_CLOCK_OPTIONAL
--
2.39.5
next reply other threads:[~2025-06-20 11:10 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-20 11:10 Arnd Bergmann [this message]
2025-06-20 13:33 ` [PATCH] [RFC] net/mlx5: don't build with CONFIG_CPUMASK_OFFSTACK Dragos Tatulea
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