diff --git a/Documentation/networking/pktgen.rst b/Documentation/networking/pktgen.rst index 1225f0f63ff0..c945218946e1 100644 --- a/Documentation/networking/pktgen.rst +++ b/Documentation/networking/pktgen.rst @@ -178,6 +178,7 @@ Examples:: IPSEC # IPsec encapsulation (needs CONFIG_XFRM) NODE_ALLOC # node specific memory allocation NO_TIMESTAMP # disable timestamping + SHARED # enable shared SKB pgset 'flag ![name]' Clear a flag to determine behaviour. Note that you might need to use single quote in interactive mode, so that your shell wouldn't expand @@ -288,6 +289,16 @@ To avoid breaking existing testbed scripts for using AH type and tunnel mode, you can use "pgset spi SPI_VALUE" to specify which transformation mode to employ. +Disable shared SKB +================== +By default, SKBs sent by pktgen are shared (user count > 1). +To test with non-shared SKBs, remove the "SHARED" flag by simply setting:: + + pg_set "flag !SHARED" + +However, if the "clone_skb" or "burst" parameters are configured, the skb +still needs to be held by pktgen for further access. Hence the skb must be +shared. Current commands and configuration options ========================================== @@ -357,6 +368,7 @@ Current commands and configuration options IPSEC NODE_ALLOC NO_TIMESTAMP + SHARED spi (ipsec) diff --git a/net/core/pktgen.c b/net/core/pktgen.c index 48306a101fd9..5e865af82e5b 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -200,6 +200,7 @@ pf(VID_RND) /* Random VLAN ID */ \ pf(SVID_RND) /* Random SVLAN ID */ \ pf(NODE) /* Node memory alloc*/ \ + pf(SHARED) /* Shared SKB */ \ #define pf(flag) flag##_SHIFT, enum pkt_flags { @@ -1198,7 +1199,8 @@ static ssize_t pktgen_if_write(struct file *file, ((pkt_dev->xmit_mode == M_NETIF_RECEIVE) || !(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING))) return -ENOTSUPP; - if (value > 0 && pkt_dev->n_imix_entries > 0) + if (value > 0 && (pkt_dev->n_imix_entries > 0 || + !(pkt_dev->flags & F_SHARED))) return -EINVAL; i += len; @@ -1257,6 +1259,10 @@ static ssize_t pktgen_if_write(struct file *file, ((pkt_dev->xmit_mode == M_START_XMIT) && (!(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING))))) return -ENOTSUPP; + + if (value > 1 && !(pkt_dev->flags & F_SHARED)) + return -EINVAL; + pkt_dev->burst = value < 1 ? 1 : value; sprintf(pg_result, "OK: burst=%u", pkt_dev->burst); return count; @@ -1334,10 +1340,19 @@ static ssize_t pktgen_if_write(struct file *file, flag = pktgen_read_flag(f, &disable); if (flag) { - if (disable) + if (disable) { + /* If "clone_skb", or "burst" parameters are + * configured, it means that the skb still + * needs to be referenced by the pktgen, so + * the skb must be shared. + */ + if (flag == F_SHARED && (pkt_dev->clone_skb || + pkt_dev->burst > 1)) + return -EINVAL; pkt_dev->flags &= ~flag; - else + } else { pkt_dev->flags |= flag; + } sprintf(pg_result, "OK: flags=0x%x", pkt_dev->flags); return count; @@ -3446,12 +3461,24 @@ static void pktgen_wait_for_skb(struct pktgen_dev *pkt_dev) static void pktgen_xmit(struct pktgen_dev *pkt_dev) { - unsigned int burst = READ_ONCE(pkt_dev->burst); + bool skb_shared = !!(READ_ONCE(pkt_dev->flags) & F_SHARED); struct net_device *odev = pkt_dev->odev; struct netdev_queue *txq; + unsigned int burst = 1; struct sk_buff *skb; + int clone_skb = 0; int ret; + /* If 'skb_shared' is false, the read of possible + * new values (if any) for 'burst' and 'clone_skb' will be skipped to + * prevent some concurrent changes from slipping in. And the stabilized + * config will be read in during the next run of pktgen_xmit. + */ + if (skb_shared) { + burst = READ_ONCE(pkt_dev->burst); + clone_skb = READ_ONCE(pkt_dev->clone_skb); + } + /* If device is offline, then don't send */ if (unlikely(!netif_running(odev) || !netif_carrier_ok(odev))) { pktgen_stop_device(pkt_dev); @@ -3468,7 +3495,7 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev) /* If no skb or clone count exhausted then get new one */ if (!pkt_dev->skb || (pkt_dev->last_ok && - ++pkt_dev->clone_count >= pkt_dev->clone_skb)) { + ++pkt_dev->clone_count >= clone_skb)) { /* build a new pkt */ kfree_skb(pkt_dev->skb); @@ -3489,7 +3516,8 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev) if (pkt_dev->xmit_mode == M_NETIF_RECEIVE) { skb = pkt_dev->skb; skb->protocol = eth_type_trans(skb, skb->dev); - refcount_add(burst, &skb->users); + if (skb_shared) + refcount_add(burst, &skb->users); local_bh_disable(); do { ret = netif_receive_skb(skb); @@ -3497,6 +3525,10 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev) pkt_dev->errors++; pkt_dev->sofar++; pkt_dev->seq_num++; + if (unlikely(!skb_shared)) { + pkt_dev->skb = NULL; + break; + } if (refcount_read(&skb->users) != burst) { /* skb was queued by rps/rfs or taps, * so cannot reuse this skb @@ -3515,9 +3547,14 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev) goto out; /* Skips xmit_mode M_START_XMIT */ } else if (pkt_dev->xmit_mode == M_QUEUE_XMIT) { local_bh_disable(); - refcount_inc(&pkt_dev->skb->users); + if (skb_shared) + refcount_inc(&pkt_dev->skb->users); ret = dev_queue_xmit(pkt_dev->skb); + + if (!skb_shared && dev_xmit_complete(ret)) + pkt_dev->skb = NULL; + switch (ret) { case NET_XMIT_SUCCESS: pkt_dev->sofar++; @@ -3555,11 +3592,15 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev) pkt_dev->last_ok = 0; goto unlock; } - refcount_add(burst, &pkt_dev->skb->users); + if (skb_shared) + refcount_add(burst, &pkt_dev->skb->users); xmit_more: ret = netdev_start_xmit(pkt_dev->skb, odev, txq, --burst > 0); + if (!skb_shared && dev_xmit_complete(ret)) + pkt_dev->skb = NULL; + switch (ret) { case NETDEV_TX_OK: pkt_dev->last_ok = 1; @@ -3581,7 +3622,8 @@ xmit_more: fallthrough; case NETDEV_TX_BUSY: /* Retry it next time */ - refcount_dec(&(pkt_dev->skb->users)); + if (skb_shared) + refcount_dec(&pkt_dev->skb->users); pkt_dev->last_ok = 0; } if (unlikely(burst)) @@ -3594,7 +3636,8 @@ out: /* If pkt_dev->count is zero, then run forever */ if ((pkt_dev->count != 0) && (pkt_dev->sofar >= pkt_dev->count)) { - pktgen_wait_for_skb(pkt_dev); + if (pkt_dev->skb) + pktgen_wait_for_skb(pkt_dev); /* Done with this */ pktgen_stop_device(pkt_dev); @@ -3777,6 +3820,7 @@ static int pktgen_add_device(struct pktgen_thread *t, const char *ifname) pkt_dev->svlan_id = 0xffff; pkt_dev->burst = 1; pkt_dev->node = NUMA_NO_NODE; + pkt_dev->flags = F_SHARED; /* SKB shared by default */ err = pktgen_setup_dev(t->net, pkt_dev, ifname); if (err)