[PATCH/RFC] mlx4_core: module param to limit msix vec allocation

Commit Message

Arthur Kepner June 10, 2010, 4:59 p.m. UTC

None

Patch

diff --git a/drivers/net/mlx4/main.c b/drivers/net/mlx4/main.c
index e3e0d54..0a316d0 100644
--- a/drivers/net/mlx4/main.c
+++ b/drivers/net/mlx4/main.c
@@ -68,6 +68,10 @@  static int msi_x = 1;
 module_param(msi_x, int, 0444);
 MODULE_PARM_DESC(msi_x, "attempt to use MSI-X if nonzero");
 
+static int max_msi_x_vec = 64;
+module_param(max_msi_x_vec, int, 0444);
+MODULE_PARM_DESC(max_msi_x_vec, "max MSI-X vectors we'll attempt to allocate");
+
 #else /* CONFIG_PCI_MSI */
 
 #define msi_x (0)
@@ -968,8 +972,10 @@  static void mlx4_enable_msi_x(struct mlx4_dev *dev)
 	int i;
 
 	if (msi_x) {
+		nreq = min_t(int, num_possible_cpus() + 1, max_msi_x_vec);
 		nreq = min_t(int, dev->caps.num_eqs - dev->caps.reserved_eqs,
-			     num_possible_cpus() + 1);
+			     nreq);
+
 		entries = kcalloc(nreq, sizeof *entries, GFP_KERNEL);
 		if (!entries)
 			goto no_msi;