From f5ad2ead846e3a00d040d64c7eaf67b65629f51d Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 12 Jun 2026 22:15:59 +0200 Subject: [PATCH] RDMa/mlx5: Avoid frame overflow warning Building mlx5 on s390 shows a rather high stack usage that can exceed the warning limit when that is set to a lower but still reasonable value: drivers/infiniband/hw/mlx5/wr.c:1051:5: error: stack frame size (1328) exceeds limit (1280) in 'mlx5_ib_post_send' [-Werror,-Wframe-larger-than] The problem here is 'struct ib_reg_wr' on the stack of handle_reg_mr_integrity(), which gets inlined into mlx5_ib_post_send() along with a number of smaller functions. Keeping the inner function out of line like gcc does avoids the warning and reduces the total stack usage in other functions called from mlx5_ib_post_send(), though handle_reg_mr_integrity() itself still has the same problem as before. Signed-off-by: Arnd Bergmann Link: https://patch.msgid.link/20260612201611.4127750-1-arnd@kernel.org Signed-off-by: Leon Romanovsky --- drivers/infiniband/hw/mlx5/wr.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/infiniband/hw/mlx5/wr.c b/drivers/infiniband/hw/mlx5/wr.c index 9947feb7fb8a..fca9e1d9d5e9 100644 --- a/drivers/infiniband/hw/mlx5/wr.c +++ b/drivers/infiniband/hw/mlx5/wr.c @@ -840,13 +840,15 @@ static int handle_psv(struct mlx5_ib_dev *dev, struct mlx5_ib_qp *qp, return err; } -static int handle_reg_mr_integrity(struct mlx5_ib_dev *dev, - struct mlx5_ib_qp *qp, - const struct ib_send_wr *wr, - struct mlx5_wqe_ctrl_seg **ctrl, void **seg, - int *size, void **cur_edge, - unsigned int *idx, int nreq, u8 fence, - u8 next_fence) +static noinline_for_stack int handle_reg_mr_integrity(struct mlx5_ib_dev *dev, + struct mlx5_ib_qp *qp, + const struct ib_send_wr *wr, + struct mlx5_wqe_ctrl_seg **ctrl, + void **seg, + int *size, void **cur_edge, + unsigned int *idx, int nreq, + u8 fence, + u8 next_fence) { struct mlx5_ib_mr *mr; struct mlx5_ib_mr *pi_mr;