diff mbox

[dpdk-dev,v2] fm10k: fix switch manager high CPU usage

Message ID 1454589920-801-1-git-send-email-shaopeng.he@intel.com (mailing list archive)
State Superseded, archived
Headers

Commit Message

He, Shaopeng Feb. 4, 2016, 12:45 p.m. UTC 
  fm10k switch core uses source MAC + VID + SGLORT to do
look up in MAC table. If no match, an exception interrupt
will be sent to the switch manager. Too much of this kind
of exception interrupts cause switch manager side high CPU
usage.
To reproduce this issue, one DPDK testpmd runs on a server
with one fm10k NIC, mac forwards test traffic from one of
fm10k ports to another port. The CPU usage for the switch
manager will go up to about 20% for test traffic rate at
10G bps, comparing to near 0% for no test traffic.
This patch fixes this issue. A default SGLORT is assigned
to each TX queue. This default value works for non-VMDq mode
and current VMDq example. For advanced VMDq usage, e.g.
different source MAC address for different TX queue, FTAG
forwarding function could be used to change this default
SGLORT value.

Signed-off-by: Shaopeng He <shaopeng.he@intel.com>
---
 drivers/net/fm10k/fm10k_ethdev.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Chen, Jing D Feb. 5, 2016, 9:26 a.m. UTC | #1 
Hi,

Best Regards,
Mark


> -----Original Message-----
> From: He, Shaopeng
> Sent: Thursday, February 04, 2016 8:45 PM
> To: dev@dpdk.org
> Cc: Chen, Jing D; Wang, Xiao W; He, Shaopeng
> Subject: [PATCH v2] fm10k: fix switch manager high CPU usage
> 
> fm10k switch core uses source MAC + VID + SGLORT to do
> look up in MAC table. If no match, an exception interrupt
> will be sent to the switch manager. Too much of this kind
> of exception interrupts cause switch manager side high CPU
> usage.
> To reproduce this issue, one DPDK testpmd runs on a server
> with one fm10k NIC, mac forwards test traffic from one of
> fm10k ports to another port. The CPU usage for the switch
> manager will go up to about 20% for test traffic rate at
> 10G bps, comparing to near 0% for no test traffic.
> This patch fixes this issue. A default SGLORT is assigned
> to each TX queue. This default value works for non-VMDq mode
> and current VMDq example. For advanced VMDq usage, e.g.
> different source MAC address for different TX queue, FTAG
> forwarding function could be used to change this default
> SGLORT value.
> 
> Signed-off-by: Shaopeng He <shaopeng.he@intel.com>
Acked-by: Jing Chen <jing.d.chen@intel.com>
diff mbox

Patch

diff --git a/drivers/net/fm10k/fm10k_ethdev.c b/drivers/net/fm10k/fm10k_ethdev.c
index e4aed94..f6eb05d 100644
--- a/drivers/net/fm10k/fm10k_ethdev.c
+++ b/drivers/net/fm10k/fm10k_ethdev.c
@@ -675,6 +675,9 @@  fm10k_dev_tx_init(struct rte_eth_dev *dev)
 		FM10K_WRITE_REG(hw, FM10K_TDBAH(i),
 				base_addr >> (CHAR_BIT * sizeof(uint32_t)));
 		FM10K_WRITE_REG(hw, FM10K_TDLEN(i), size);
+
+		/* assign default SGLORT for each TX queue */
+		FM10K_WRITE_REG(hw, FM10K_TX_SGLORT(i), hw->mac.dglort_map);
 	}
 
 	/* set up vector or scalar TX function as appropriate */