On 10/16/25 17:36, Alexander Lobakin wrote:
From: Michal Swiatkowski <[email protected]>
Date: Thu, 16 Oct 2025 08:22:50 +0200
On some high-core systems loading ice driver with default values can
lead to queue/irq exhaustion. It will result in no additional resources
for SR-IOV.
In most cases there is no performance reason for more than 64 queues.
Limit the default value to 64. Still, using ethtool the number of
queues can be changed up to num_online_cpus().
This change affects only the default queue amount on systems with more
than 64 cores.
Reviewed-by: Jacob Keller <[email protected]>
Signed-off-by: Michal Swiatkowski <[email protected]>
---
drivers/net/ethernet/intel/ice/ice.h | 20 ++++++++++++++++++++
drivers/net/ethernet/intel/ice/ice_irq.c | 6 ++++--
drivers/net/ethernet/intel/ice/ice_lib.c | 8 ++++----
3 files changed, 28 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice.h
b/drivers/net/ethernet/intel/ice/ice.h
index 3d4d8b88631b..354ec2950ff3 100644
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h
@@ -1133,4 +1133,24 @@ static inline struct ice_hw *ice_get_primary_hw(struct
ice_pf *pf)
else
return &pf->adapter->ctrl_pf->hw;
}
+
+/**
+ * ice_capped_num_cpus - normalize the number of CPUs to a reasonable limit
+ *
+ * This function returns the number of online CPUs, but caps it at suitable
+ * default to prevent excessive resource allocation on systems with very high
+ * CPU counts.
+ *
+ * Note: suitable default is currently at 64, which is reflected in
default_cpus
+ * constant. In most cases there is no much benefit for more than 64 and it is
a
+ * power of 2 number.
+ *
+ * Return: number of online CPUs, capped at suitable default.
+ */
+static inline u16 ice_capped_num_cpus(void)
+{
+ const int default_cpus = 64;
Maybe we should just use netif_get_num_default_rss_queues() like I did
in idpf?
Or it still can be too high e.g. on clusters with > 256 CPUs?
good point,
perhaps we should both use it and change the (kernel) func to cap at 64
+
+ return min(num_online_cpus(), default_cpus);
+}
#endif /* _ICE_H_ */
Thanks,
Olek
