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Date: Tue, 05 May 2015 22:30:38 +0200
From: Jesper Dangaard Brouer <brouer@...hat.com>
To: Jesper Dangaard Brouer <brouer@...hat.com>, netdev@...r.kernel.org
Cc: Eric Dumazet <eric.dumazet@...il.com>,
Alexei Starovoitov <ast@...mgrid.com>
Subject: [PATCH 2/2] pktgen: introduce xmit_mode 'rx_inject'
From: Alexei Starovoitov <ast@...mgrid.com>
Introduce xmit_mode 'rx_inject' for pktgen which generates the packets
using familiar pktgen commands, but feeds them into
netif_receive_skb() instead of ndo_start_xmit().
It is designed to test netif_receive_skb and ingress qdisc
performace only. Make sure to understand how it works before
using it for other rx benchmarking.
Sample script 'pktgen.sh':
\#!/bin/bash
function pgset() {
local result
echo $1 > $PGDEV
result=`cat $PGDEV | fgrep "Result: OK:"`
if [ "$result" = "" ]; then
cat $PGDEV | fgrep Result:
fi
}
ETH=$1
PGDEV=/proc/net/pktgen/kpktgend_0
pgset "rem_device_all"
pgset "add_device $ETH"
PGDEV=/proc/net/pktgen/$ETH
pgset "xmit_mode rx_inject"
pgset "pkt_size 60"
pgset "dst 99.1.1.2"
pgset "dst_mac 90:e2:ba:6e:a8:e5"
pgset "count 10000000"
pgset "burst 32"
PGDEV=/proc/net/pktgen/pgctrl
echo "Running... ctrl^C to stop"
pgset "start"
echo "Done"
cat /proc/net/pktgen/$ETH
Usage:
$ sudo ./pktgen.sh eth2
...
Result: OK: 232376(c232372+d3) usec, 10000000 (60byte,0frags)
43033682pps 20656Mb/sec (20656167360bps) errors: 10000000
Raw netif_receive_skb speed should be ~43 million packet
per second on 3.7Ghz x86 and 'perf report' should look like:
37.69% kpktgend_0 [kernel.vmlinux] [k] __netif_receive_skb_core
25.81% kpktgend_0 [kernel.vmlinux] [k] kfree_skb
7.22% kpktgend_0 [kernel.vmlinux] [k] ip_rcv
5.68% kpktgend_0 [pktgen] [k] pktgen_thread_worker
If fib_table_lookup is seen on top, it means skb was processed
by the stack. To benchmark netif_receive_skb only make sure
that 'dst_mac' of your pktgen script is different from
receiving device mac and it will be dropped by ip_rcv
Signed-off-by: Alexei Starovoitov <ast@...mgrid.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@...hat.com>
---
v3->v4: Jesper address his own concerns
- User interface intro xmit_mode
- Mention xmit_mode in doc
- Make sure skb_clone cannot be used together with this mode
v2->v3: addressed more Eric comments. Thanks!
v1->v2: as suggested by Eric:
- dropped 'clone_skb' flag, now it will return enotsupp
- fix rps/rfs bug by checking skb->users after every netif_receive_skb
- tested with RPS/RFS, taps, veth, physical devs, various tc cls/act
---
Documentation/networking/pktgen.txt | 7 +++
net/core/pktgen.c | 84 +++++++++++++++++++++++++++++++++--
2 files changed, 86 insertions(+), 5 deletions(-)
diff --git a/Documentation/networking/pktgen.txt b/Documentation/networking/pktgen.txt
index 6199ee6..bfb5f2c 100644
--- a/Documentation/networking/pktgen.txt
+++ b/Documentation/networking/pktgen.txt
@@ -193,6 +193,10 @@ Examples:
pgset "rate 300M" set rate to 300 Mb/s
pgset "ratep 1000000" set rate to 1Mpps
+ pgset "xmit_mode rx_inject" RX inject packets into stack netif_receive_skb()
+ Works with "burst" but not with "clone_skb".
+ Default xmit_mode is "tx".
+
Sample scripts
==============
@@ -310,6 +314,9 @@ flowlen
rate
ratep
+xmit_mode
+
+
References:
ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/
ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/examples/
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 43bb215..85195b2 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -210,6 +210,10 @@
#define T_REMDEVALL (1<<2) /* Remove all devs */
#define T_REMDEV (1<<3) /* Remove one dev */
+/* Xmit modes */
+#define M_TX 0 /* Default normal TX */
+#define M_RX_INJECT 1 /* RX inject packet into stack */
+
/* If lock -- protects updating of if_list */
#define if_lock(t) spin_lock(&(t->if_lock));
#define if_unlock(t) spin_unlock(&(t->if_lock));
@@ -251,13 +255,14 @@ struct pktgen_dev {
* we will do a random selection from within the range.
*/
__u32 flags;
- int removal_mark; /* non-zero => the device is marked for
- * removal by worker thread */
-
+ int xmit_mode;
int min_pkt_size;
int max_pkt_size;
int pkt_overhead; /* overhead for MPLS, VLANs, IPSEC etc */
int nfrags;
+ int removal_mark; /* non-zero => the device is marked for
+ * removal by worker thread */
+
struct page *page;
u64 delay; /* nano-seconds */
@@ -620,6 +625,9 @@ static int pktgen_if_show(struct seq_file *seq, void *v)
if (pkt_dev->node >= 0)
seq_printf(seq, " node: %d\n", pkt_dev->node);
+ if (pkt_dev->xmit_mode == M_RX_INJECT)
+ seq_puts(seq, " xmit_mode: rx_inject\n");
+
seq_puts(seq, " Flags: ");
if (pkt_dev->flags & F_IPV6)
@@ -1081,7 +1089,8 @@ static ssize_t pktgen_if_write(struct file *file,
if (len < 0)
return len;
if ((value > 0) &&
- (!(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))
+ ((pkt_dev->xmit_mode == M_RX_INJECT) ||
+ !(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))
return -ENOTSUPP;
i += len;
pkt_dev->clone_skb = value;
@@ -1134,7 +1143,7 @@ static ssize_t pktgen_if_write(struct file *file,
return len;
i += len;
- if ((value > 1) &&
+ if ((value > 1) && (pkt_dev->xmit_mode == M_TX) &&
(!(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))
return -ENOTSUPP;
pkt_dev->burst = value < 1 ? 1 : value;
@@ -1160,6 +1169,35 @@ static ssize_t pktgen_if_write(struct file *file,
sprintf(pg_result, "ERROR: node not possible");
return count;
}
+ if (!strcmp(name, "xmit_mode")) {
+ char f[32];
+
+ memset(f, 0, 32);
+ len = strn_len(&user_buffer[i], sizeof(f) - 1);
+ if (len < 0)
+ return len;
+
+ if (copy_from_user(f, &user_buffer[i], len))
+ return -EFAULT;
+ i += len;
+
+ if (strcmp(f, "tx") == 0) {
+ pkt_dev->xmit_mode = M_TX;
+ } else if (strcmp(f, "rx_inject") == 0) {
+ /* clone_skb set earlier, not supported in this mode */
+ if (pkt_dev->clone_skb > 0)
+ return -ENOTSUPP;
+
+ pkt_dev->xmit_mode = M_RX_INJECT;
+ } else {
+ sprintf(pg_result,
+ "xmit_mode -:%s:- unknown\nAvailable modes: %s",
+ f, "tx, rx_inject\n");
+ return count;
+ }
+ sprintf(pg_result, "OK: xmit_mode=%s", f);
+ return count;
+ }
if (!strcmp(name, "flag")) {
char f[32];
memset(f, 0, 32);
@@ -3320,6 +3358,7 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
unsigned int burst = ACCESS_ONCE(pkt_dev->burst);
struct net_device *odev = pkt_dev->odev;
struct netdev_queue *txq;
+ struct sk_buff *skb;
int ret;
/* If device is offline, then don't send */
@@ -3352,11 +3391,45 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
pkt_dev->last_pkt_size = pkt_dev->skb->len;
pkt_dev->allocated_skbs++;
pkt_dev->clone_count = 0; /* reset counter */
+ if (pkt_dev->xmit_mode == M_RX_INJECT)
+ pkt_dev->skb->protocol = eth_type_trans(pkt_dev->skb,
+ pkt_dev->skb->dev);
}
if (pkt_dev->delay && pkt_dev->last_ok)
spin(pkt_dev, pkt_dev->next_tx);
+ if (pkt_dev->xmit_mode == M_RX_INJECT) {
+ skb = pkt_dev->skb;
+ atomic_add(burst, &skb->users);
+ local_bh_disable();
+ do {
+ ret = netif_receive_skb(skb);
+ if (ret == NET_RX_DROP)
+ pkt_dev->errors++;
+ pkt_dev->sofar++;
+ pkt_dev->seq_num++;
+ if (atomic_read(&skb->users) != burst) {
+ /* skb was queued by rps/rfs or taps,
+ * so cannot reuse this skb
+ */
+ atomic_sub(burst - 1, &skb->users);
+ /* get out of the loop and wait
+ * until skb is consumed
+ */
+ pkt_dev->last_ok = 1;
+ break;
+ }
+ /* skb was 'freed' by stack, so clean few
+ * bits and reuse it
+ */
+#ifdef CONFIG_NET_CLS_ACT
+ skb->tc_verd = 0; /* reset reclass/redir ttl */
+#endif
+ } while (--burst > 0);
+ goto out; /* Skips xmit_mode M_TX */
+ }
+
txq = skb_get_tx_queue(odev, pkt_dev->skb);
local_bh_disable();
@@ -3404,6 +3477,7 @@ xmit_more:
unlock:
HARD_TX_UNLOCK(odev, txq);
+out:
local_bh_enable();
/* If pkt_dev->count is zero, then run forever */
--
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