lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Fri, 29 May 2020 20:43:42 +0300
From:   Ioana Ciornei <ioana.ciornei@....com>
To:     netdev@...r.kernel.org
Cc:     kuba@...nel.org, davem@...emloft.net,
        Ioana Radulescu <ruxandra.radulescu@....com>,
        Ioana Ciornei <ioana.ciornei@....com>
Subject: [PATCH net-next v3 4/7] dpaa2-eth: Add congestion group taildrop

From: Ioana Radulescu <ruxandra.radulescu@....com>

The increase in number of ingress frame queues means we now risk
depleting the buffer pool before the FQ taildrop kicks in.

Congestion group taildrop allows us to control the number of frames that
can accumulate on a group of Rx frame queues belonging to the same
traffic class.  This setting coexists with the frame queue based
taildrop: whichever limit gets hit first triggers the frame drop.

Signed-off-by: Ioana Radulescu <ruxandra.radulescu@....com>
Signed-off-by: Ioana Ciornei <ioana.ciornei@....com>
---
Changes in v3:
 - none

 .../net/ethernet/freescale/dpaa2/dpaa2-eth.c  | 35 ++++++++++++++-----
 .../net/ethernet/freescale/dpaa2/dpaa2-eth.h  | 13 +++++--
 2 files changed, 38 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
index c521f4afba8e..8cbbebefdcfd 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
@@ -1287,17 +1287,20 @@ static void disable_ch_napi(struct dpaa2_eth_priv *priv)
 	}
 }
 
-static void dpaa2_eth_set_rx_taildrop(struct dpaa2_eth_priv *priv, bool enable)
+static void dpaa2_eth_set_rx_taildrop(struct dpaa2_eth_priv *priv,
+				      bool tx_pause)
 {
 	struct dpni_taildrop td = {0};
 	struct dpaa2_eth_fq *fq;
 	int i, err;
 
-	if (priv->rx_td_enabled == enable)
+	td.enable = !tx_pause;
+	if (priv->rx_td_enabled == td.enable)
 		return;
 
-	td.enable = enable;
-	td.threshold = DPAA2_ETH_TAILDROP_THRESH;
+	/* FQ taildrop: threshold is in bytes, per frame queue */
+	td.threshold = DPAA2_ETH_FQ_TAILDROP_THRESH;
+	td.units = DPNI_CONGESTION_UNIT_BYTES;
 
 	for (i = 0; i < priv->num_fqs; i++) {
 		fq = &priv->fq[i];
@@ -1308,12 +1311,28 @@ static void dpaa2_eth_set_rx_taildrop(struct dpaa2_eth_priv *priv, bool enable)
 					fq->tc, fq->flowid, &td);
 		if (err) {
 			netdev_err(priv->net_dev,
-				   "dpni_set_taildrop() failed\n");
-			break;
+				   "dpni_set_taildrop(FQ) failed\n");
+			return;
+		}
+	}
+
+	/* Congestion group taildrop: threshold is in frames, per group
+	 * of FQs belonging to the same traffic class
+	 */
+	td.threshold = DPAA2_ETH_CG_TAILDROP_THRESH(priv);
+	td.units = DPNI_CONGESTION_UNIT_FRAMES;
+	for (i = 0; i < dpaa2_eth_tc_count(priv); i++) {
+		err = dpni_set_taildrop(priv->mc_io, 0, priv->mc_token,
+					DPNI_CP_GROUP, DPNI_QUEUE_RX,
+					i, 0, &td);
+		if (err) {
+			netdev_err(priv->net_dev,
+				   "dpni_set_taildrop(CG) failed\n");
+			return;
 		}
 	}
 
-	priv->rx_td_enabled = enable;
+	priv->rx_td_enabled = td.enable;
 }
 
 static int link_state_update(struct dpaa2_eth_priv *priv)
@@ -1334,7 +1353,7 @@ static int link_state_update(struct dpaa2_eth_priv *priv)
 	 * only when pause frame generation is disabled.
 	 */
 	tx_pause = dpaa2_eth_tx_pause_enabled(state.options);
-	dpaa2_eth_set_rx_taildrop(priv, !tx_pause);
+	dpaa2_eth_set_rx_taildrop(priv, tx_pause);
 
 	/* When we manage the MAC/PHY using phylink there is no need
 	 * to manually update the netif_carrier.
diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
index 6384f6a23349..184d5d83e497 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
@@ -40,7 +40,7 @@
  * frames in the Rx queues (length of the current frame is not
  * taken into account when making the taildrop decision)
  */
-#define DPAA2_ETH_TAILDROP_THRESH	(64 * 1024)
+#define DPAA2_ETH_FQ_TAILDROP_THRESH	(64 * 1024)
 
 /* Maximum number of Tx confirmation frames to be processed
  * in a single NAPI call
@@ -52,11 +52,20 @@
  * how many 64B frames fit inside the taildrop threshold and add a margin
  * to accommodate the buffer refill delay.
  */
-#define DPAA2_ETH_MAX_FRAMES_PER_QUEUE	(DPAA2_ETH_TAILDROP_THRESH / 64)
+#define DPAA2_ETH_MAX_FRAMES_PER_QUEUE	(DPAA2_ETH_FQ_TAILDROP_THRESH / 64)
 #define DPAA2_ETH_NUM_BUFS		(DPAA2_ETH_MAX_FRAMES_PER_QUEUE + 256)
 #define DPAA2_ETH_REFILL_THRESH \
 	(DPAA2_ETH_NUM_BUFS - DPAA2_ETH_BUFS_PER_CMD)
 
+/* Congestion group taildrop threshold: number of frames allowed to accumulate
+ * at any moment in a group of Rx queues belonging to the same traffic class.
+ * Choose value such that we don't risk depleting the buffer pool before the
+ * taildrop kicks in
+ */
+#define DPAA2_ETH_CG_TAILDROP_THRESH(priv)				\
+	(DPAA2_ETH_MAX_FRAMES_PER_QUEUE * dpaa2_eth_queue_count(priv) /	\
+	 dpaa2_eth_tc_count(priv))
+
 /* Maximum number of buffers that can be acquired/released through a single
  * QBMan command
  */
-- 
2.17.1

Powered by blists - more mailing lists