[PATCH 4.14 40/92] qed: Limit msix vectors in kdump kernel to the minimum required count.

From: Greg Kroah-Hartman
Date: Fri Jul 20 2018 - 08:35:18 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Sudarsana Reddy Kalluru <sudarsana.kalluru@xxxxxxxxxx>

[ Upstream commit bb7858ba1102f82470a917e041fd23e6385c31be ]

Memory size is limited in the kdump kernel environment. Allocation of more
msix-vectors (or queues) consumes few tens of MBs of memory, which might
lead to the kdump kernel failure.
This patch adds changes to limit the number of MSI-X vectors in kdump
kernel to minimum required value (i.e., 2 per engine).

Fixes: fe56b9e6a ("qed: Add module with basic common support")
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@xxxxxxxxxx>
Signed-off-by: Michal Kalderon <Michal.Kalderon@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/qlogic/qed/qed_main.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/drivers/net/ethernet/qlogic/qed/qed_main.c
+++ b/drivers/net/ethernet/qlogic/qed/qed_main.c
@@ -779,6 +779,14 @@ static int qed_slowpath_setup_int(struct
/* We want a minimum of one slowpath and one fastpath vector per hwfn */
cdev->int_params.in.min_msix_cnt = cdev->num_hwfns * 2;

+ if (is_kdump_kernel()) {
+ DP_INFO(cdev,
+ "Kdump kernel: Limit the max number of requested MSI-X vectors to %hd\n",
+ cdev->int_params.in.min_msix_cnt);
+ cdev->int_params.in.num_vectors =
+ cdev->int_params.in.min_msix_cnt;
+ }
+
rc = qed_set_int_mode(cdev, false);
if (rc) {
DP_ERR(cdev, "qed_slowpath_setup_int ERR\n");