leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

cxgb4: request the TX CIDX updates to status page

Browse Source 
For adapters which support the SGE Doorbell Queue Timer facility,
we configured the Ethernet TX Queues to send CIDX Updates to the
Associated Ethernet RX Response Queue with CPL_SGE_EGR_UPDATE
messages to allow us to respond more quickly to the CIDX Updates.
But, this was adding load to PCIe Link RX bandwidth and,
potentially, resulting in higher CPU Interrupt load.

This patch requests the HW to deliver the CIDX updates to the TX
queue status page rather than generating an ingress queue message
(as an interrupt). With this patch, the load on RX bandwidth is
reduced and a substantial improvement in BW is noticed at lower
IO sizes.

Fixes: d429005fdf ("cxgb4/cxgb4vf: Add support for SGE doorbell queue timer")
Signed-off-by: Raju Rangoju <rajur@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Raju Rangoju 2019-10-23 23:03:55 +05:30 committed by David S. Miller
parent d4e4fdf9e4
commit 7c3bebc3d8
1 changed files with 2 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/net/ethernet/chelsio/cxgb4/sge.c
View File

@ -3791,15 +3791,11 @@ int t4_sge_alloc_eth_txq(struct adapter *adap, struct sge_eth_txq *txq,
* write the CIDX Updates into the Status Page at the end of the
* TX Queue.
*/
c.autoequiqe_to_viid = htonl((dbqt
? FW_EQ_ETH_CMD_AUTOEQUIQE_F
: FW_EQ_ETH_CMD_AUTOEQUEQE_F) |
c.autoequiqe_to_viid = htonl(FW_EQ_ETH_CMD_AUTOEQUEQE_F |
FW_EQ_ETH_CMD_VIID_V(pi->viid));
c.fetchszm_to_iqid =
htonl(FW_EQ_ETH_CMD_HOSTFCMODE_V(dbqt
? HOSTFCMODE_INGRESS_QUEUE_X
: HOSTFCMODE_STATUS_PAGE_X) |
htonl(FW_EQ_ETH_CMD_HOSTFCMODE_V(HOSTFCMODE_STATUS_PAGE_X) |
FW_EQ_ETH_CMD_PCIECHN_V(pi->tx_chan) |
FW_EQ_ETH_CMD_FETCHRO_F | FW_EQ_ETH_CMD_IQID_V(iqid));