| Message ID | 5277a40b08c491bd4ff8f6e3276718848f7406e8.1475246890.git.pabeni@redhat.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Fri, 2016-09-30 at 16:56 +0200, Paolo Abeni wrote: > The commit 879c7220e828 ("net: pktgen: Observe needed_headroom > of the device") increased the 'pkt_overhead' field value by > LL_RESERVED_SPACE. > As a side effect the generated packet size, computed as: > > /* Eth + IPh + UDPh + mpls */ > datalen = pkt_dev->cur_pkt_size - 14 - 20 - 8 - > pkt_dev->pkt_overhead; > > is decreased by the same value. > The above changed slightly the behavior of existing pktgen users, > and made the procfs interface somewhat inconsistent. > Fix it by restoring the previous pkt_overhead value and using > LL_RESERVED_SPACE as extralen in skb allocation. > Also, change pktgen_alloc_skb() to only partially reserve > the headroom to allow the caller to prefetch from ll header > start. > > v1 -> v2: > - fixed some typos in the comments > > Fixes: 879c7220e828 ("net: pktgen: Observe needed_headroom of the device") > Suggested-by: Ben Greear <greearb@candelatech.com> > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > --- > net/core/pktgen.c | 21 ++++++++++----------- > 1 file changed, 10 insertions(+), 11 deletions(-) > > diff --git a/net/core/pktgen.c b/net/core/pktgen.c > index bbd118b..5219a9e 100644 > --- a/net/core/pktgen.c > +++ b/net/core/pktgen.c > @@ -2286,7 +2286,7 @@ out: > > static inline void set_pkt_overhead(struct pktgen_dev *pkt_dev) > { > - pkt_dev->pkt_overhead = LL_RESERVED_SPACE(pkt_dev->odev); > + pkt_dev->pkt_overhead = 0; > pkt_dev->pkt_overhead += pkt_dev->nr_labels*sizeof(u32); > pkt_dev->pkt_overhead += VLAN_TAG_SIZE(pkt_dev); > pkt_dev->pkt_overhead += SVLAN_TAG_SIZE(pkt_dev); > @@ -2777,13 +2777,13 @@ static void pktgen_finalize_skb(struct pktgen_dev *pkt_dev, struct sk_buff *skb, > } > > static struct sk_buff *pktgen_alloc_skb(struct net_device *dev, > - struct pktgen_dev *pkt_dev, > - unsigned int extralen) > + struct pktgen_dev *pkt_dev) > { > + unsigned int extralen = LL_RESERVED_SPACE(dev); > struct sk_buff *skb = NULL; > - unsigned int size = pkt_dev->cur_pkt_size + 64 + extralen + > - pkt_dev->pkt_overhead; > + unsigned int size; > > + size = pkt_dev->cur_pkt_size + 64 + extralen + pkt_dev->pkt_overhead; > if (pkt_dev->flags & F_NODE) { > int node = pkt_dev->node >= 0 ? pkt_dev->node : numa_node_id(); > > @@ -2796,8 +2796,9 @@ static struct sk_buff *pktgen_alloc_skb(struct net_device *dev, > skb = __netdev_alloc_skb(dev, size, GFP_NOWAIT); > } > > + /* the caller pre-fetches from skb->data and reserves for the mac hdr */ > if (likely(skb)) > - skb_reserve(skb, LL_RESERVED_SPACE(dev)); > + skb_reserve(skb, extralen - 16); Is the 16 here the same as HD_DATA_MOD? Magic numbers... Thanks, - Greg > > return skb; > } > @@ -2830,16 +2831,14 @@ static struct sk_buff *fill_packet_ipv4(struct net_device *odev, > mod_cur_headers(pkt_dev); > queue_map = pkt_dev->cur_queue_map; > > - datalen = (odev->hard_header_len + 16) & ~0xf; > - > - skb = pktgen_alloc_skb(odev, pkt_dev, datalen); > + skb = pktgen_alloc_skb(odev, pkt_dev); > if (!skb) { > sprintf(pkt_dev->result, "No memory"); > return NULL; > } > > prefetchw(skb->data); > - skb_reserve(skb, datalen); > + skb_reserve(skb, 16); > > /* Reserve for ethernet and IP header */ > eth = (__u8 *) skb_push(skb, 14); > @@ -2959,7 +2958,7 @@ static struct sk_buff *fill_packet_ipv6(struct net_device *odev, > mod_cur_headers(pkt_dev); > queue_map = pkt_dev->cur_queue_map; > > - skb = pktgen_alloc_skb(odev, pkt_dev, 16); > + skb = pktgen_alloc_skb(odev, pkt_dev); > if (!skb) { > sprintf(pkt_dev->result, "No memory"); > return NULL;
On Fri, 2016-09-30 at 08:39 -0700, Greg wrote: > On Fri, 2016-09-30 at 16:56 +0200, Paolo Abeni wrote: > > The commit 879c7220e828 ("net: pktgen: Observe needed_headroom > > of the device") increased the 'pkt_overhead' field value by > > LL_RESERVED_SPACE. > > As a side effect the generated packet size, computed as: > > > > /* Eth + IPh + UDPh + mpls */ > > datalen = pkt_dev->cur_pkt_size - 14 - 20 - 8 - > > pkt_dev->pkt_overhead; > > > > is decreased by the same value. > > The above changed slightly the behavior of existing pktgen users, > > and made the procfs interface somewhat inconsistent. > > Fix it by restoring the previous pkt_overhead value and using > > LL_RESERVED_SPACE as extralen in skb allocation. > > Also, change pktgen_alloc_skb() to only partially reserve > > the headroom to allow the caller to prefetch from ll header > > start. > > > > v1 -> v2: > > - fixed some typos in the comments > > > > Fixes: 879c7220e828 ("net: pktgen: Observe needed_headroom of the device") > > Suggested-by: Ben Greear <greearb@candelatech.com> > > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > > --- > > net/core/pktgen.c | 21 ++++++++++----------- > > 1 file changed, 10 insertions(+), 11 deletions(-) > > > > diff --git a/net/core/pktgen.c b/net/core/pktgen.c > > index bbd118b..5219a9e 100644 > > --- a/net/core/pktgen.c > > +++ b/net/core/pktgen.c > > @@ -2286,7 +2286,7 @@ out: > > > > static inline void set_pkt_overhead(struct pktgen_dev *pkt_dev) > > { > > - pkt_dev->pkt_overhead = LL_RESERVED_SPACE(pkt_dev->odev); > > + pkt_dev->pkt_overhead = 0; > > pkt_dev->pkt_overhead += pkt_dev->nr_labels*sizeof(u32); > > pkt_dev->pkt_overhead += VLAN_TAG_SIZE(pkt_dev); > > pkt_dev->pkt_overhead += SVLAN_TAG_SIZE(pkt_dev); > > @@ -2777,13 +2777,13 @@ static void pktgen_finalize_skb(struct pktgen_dev *pkt_dev, struct sk_buff *skb, > > } > > > > static struct sk_buff *pktgen_alloc_skb(struct net_device *dev, > > - struct pktgen_dev *pkt_dev, > > - unsigned int extralen) > > + struct pktgen_dev *pkt_dev) > > { > > + unsigned int extralen = LL_RESERVED_SPACE(dev); > > struct sk_buff *skb = NULL; > > - unsigned int size = pkt_dev->cur_pkt_size + 64 + extralen + > > - pkt_dev->pkt_overhead; > > + unsigned int size; > > > > + size = pkt_dev->cur_pkt_size + 64 + extralen + pkt_dev->pkt_overhead; > > if (pkt_dev->flags & F_NODE) { > > int node = pkt_dev->node >= 0 ? pkt_dev->node : numa_node_id(); > > > > @@ -2796,8 +2796,9 @@ static struct sk_buff *pktgen_alloc_skb(struct net_device *dev, > > skb = __netdev_alloc_skb(dev, size, GFP_NOWAIT); > > } > > > > + /* the caller pre-fetches from skb->data and reserves for the mac hdr */ > > if (likely(skb)) > > - skb_reserve(skb, LL_RESERVED_SPACE(dev)); > > + skb_reserve(skb, extralen - 16); > > Is the 16 here the same as HD_DATA_MOD? > > Magic numbers... This magic numbers comes from the current code (the extralen argument), this patch just move it around. I can send a v3 using a define for it, if really needed, but it seems more a separated clean-up. Thank you, Paolo
From: Paolo Abeni <pabeni@redhat.com> Date: Fri, 30 Sep 2016 16:56:45 +0200 > The commit 879c7220e828 ("net: pktgen: Observe needed_headroom > of the device") increased the 'pkt_overhead' field value by > LL_RESERVED_SPACE. > As a side effect the generated packet size, computed as: > > /* Eth + IPh + UDPh + mpls */ > datalen = pkt_dev->cur_pkt_size - 14 - 20 - 8 - > pkt_dev->pkt_overhead; > > is decreased by the same value. > The above changed slightly the behavior of existing pktgen users, > and made the procfs interface somewhat inconsistent. > Fix it by restoring the previous pkt_overhead value and using > LL_RESERVED_SPACE as extralen in skb allocation. > Also, change pktgen_alloc_skb() to only partially reserve > the headroom to allow the caller to prefetch from ll header > start. > > v1 -> v2: > - fixed some typos in the comments > > Fixes: 879c7220e828 ("net: pktgen: Observe needed_headroom of the device") > Suggested-by: Ben Greear <greearb@candelatech.com> > Signed-off-by: Paolo Abeni <pabeni@redhat.com> Applied and queued up for -stable.
On Sat, 2016-10-01 at 20:05 +0200, Paolo Abeni wrote: > On Fri, 2016-09-30 at 08:39 -0700, Greg wrote: > > On Fri, 2016-09-30 at 16:56 +0200, Paolo Abeni wrote: > > > The commit 879c7220e828 ("net: pktgen: Observe needed_headroom > > > of the device") increased the 'pkt_overhead' field value by > > > LL_RESERVED_SPACE. > > > As a side effect the generated packet size, computed as: > > > > > > /* Eth + IPh + UDPh + mpls */ > > > datalen = pkt_dev->cur_pkt_size - 14 - 20 - 8 - > > > pkt_dev->pkt_overhead; > > > > > > is decreased by the same value. > > > The above changed slightly the behavior of existing pktgen users, > > > and made the procfs interface somewhat inconsistent. > > > Fix it by restoring the previous pkt_overhead value and using > > > LL_RESERVED_SPACE as extralen in skb allocation. > > > Also, change pktgen_alloc_skb() to only partially reserve > > > the headroom to allow the caller to prefetch from ll header > > > start. > > > > > > v1 -> v2: > > > - fixed some typos in the comments > > > > > > Fixes: 879c7220e828 ("net: pktgen: Observe needed_headroom of the device") > > > Suggested-by: Ben Greear <greearb@candelatech.com> > > > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > > > --- > > > net/core/pktgen.c | 21 ++++++++++----------- > > > 1 file changed, 10 insertions(+), 11 deletions(-) > > > > > > diff --git a/net/core/pktgen.c b/net/core/pktgen.c > > > index bbd118b..5219a9e 100644 > > > --- a/net/core/pktgen.c > > > +++ b/net/core/pktgen.c > > > @@ -2286,7 +2286,7 @@ out: > > > > > > static inline void set_pkt_overhead(struct pktgen_dev *pkt_dev) > > > { > > > - pkt_dev->pkt_overhead = LL_RESERVED_SPACE(pkt_dev->odev); > > > + pkt_dev->pkt_overhead = 0; > > > pkt_dev->pkt_overhead += pkt_dev->nr_labels*sizeof(u32); > > > pkt_dev->pkt_overhead += VLAN_TAG_SIZE(pkt_dev); > > > pkt_dev->pkt_overhead += SVLAN_TAG_SIZE(pkt_dev); > > > @@ -2777,13 +2777,13 @@ static void pktgen_finalize_skb(struct pktgen_dev *pkt_dev, struct sk_buff *skb, > > > } > > > > > > static struct sk_buff *pktgen_alloc_skb(struct net_device *dev, > > > - struct pktgen_dev *pkt_dev, > > > - unsigned int extralen) > > > + struct pktgen_dev *pkt_dev) > > > { > > > + unsigned int extralen = LL_RESERVED_SPACE(dev); > > > struct sk_buff *skb = NULL; > > > - unsigned int size = pkt_dev->cur_pkt_size + 64 + extralen + > > > - pkt_dev->pkt_overhead; > > > + unsigned int size; > > > > > > + size = pkt_dev->cur_pkt_size + 64 + extralen + pkt_dev->pkt_overhead; > > > if (pkt_dev->flags & F_NODE) { > > > int node = pkt_dev->node >= 0 ? pkt_dev->node : numa_node_id(); > > > > > > @@ -2796,8 +2796,9 @@ static struct sk_buff *pktgen_alloc_skb(struct net_device *dev, > > > skb = __netdev_alloc_skb(dev, size, GFP_NOWAIT); > > > } > > > > > > + /* the caller pre-fetches from skb->data and reserves for the mac hdr */ > > > if (likely(skb)) > > > - skb_reserve(skb, LL_RESERVED_SPACE(dev)); > > > + skb_reserve(skb, extralen - 16); > > > > Is the 16 here the same as HD_DATA_MOD? > > > > Magic numbers... > > This magic numbers comes from the current code (the extralen argument), > this patch just move it around. I can send a v3 using a define for it, > if really needed, but it seems more a separated clean-up. Sure, sounds good. Looks like Dave applied it. - Greg > > Thank you, > > Paolo >
diff --git a/net/core/pktgen.c b/net/core/pktgen.c index bbd118b..5219a9e 100644 --- a/net/core/pktgen.c +++ b/net/core/pktgen.c @@ -2286,7 +2286,7 @@ out: static inline void set_pkt_overhead(struct pktgen_dev *pkt_dev) { - pkt_dev->pkt_overhead = LL_RESERVED_SPACE(pkt_dev->odev); + pkt_dev->pkt_overhead = 0; pkt_dev->pkt_overhead += pkt_dev->nr_labels*sizeof(u32); pkt_dev->pkt_overhead += VLAN_TAG_SIZE(pkt_dev); pkt_dev->pkt_overhead += SVLAN_TAG_SIZE(pkt_dev); @@ -2777,13 +2777,13 @@ static void pktgen_finalize_skb(struct pktgen_dev *pkt_dev, struct sk_buff *skb, } static struct sk_buff *pktgen_alloc_skb(struct net_device *dev, - struct pktgen_dev *pkt_dev, - unsigned int extralen) + struct pktgen_dev *pkt_dev) { + unsigned int extralen = LL_RESERVED_SPACE(dev); struct sk_buff *skb = NULL; - unsigned int size = pkt_dev->cur_pkt_size + 64 + extralen + - pkt_dev->pkt_overhead; + unsigned int size; + size = pkt_dev->cur_pkt_size + 64 + extralen + pkt_dev->pkt_overhead; if (pkt_dev->flags & F_NODE) { int node = pkt_dev->node >= 0 ? pkt_dev->node : numa_node_id(); @@ -2796,8 +2796,9 @@ static struct sk_buff *pktgen_alloc_skb(struct net_device *dev, skb = __netdev_alloc_skb(dev, size, GFP_NOWAIT); } + /* the caller pre-fetches from skb->data and reserves for the mac hdr */ if (likely(skb)) - skb_reserve(skb, LL_RESERVED_SPACE(dev)); + skb_reserve(skb, extralen - 16); return skb; } @@ -2830,16 +2831,14 @@ static struct sk_buff *fill_packet_ipv4(struct net_device *odev, mod_cur_headers(pkt_dev); queue_map = pkt_dev->cur_queue_map; - datalen = (odev->hard_header_len + 16) & ~0xf; - - skb = pktgen_alloc_skb(odev, pkt_dev, datalen); + skb = pktgen_alloc_skb(odev, pkt_dev); if (!skb) { sprintf(pkt_dev->result, "No memory"); return NULL; } prefetchw(skb->data); - skb_reserve(skb, datalen); + skb_reserve(skb, 16); /* Reserve for ethernet and IP header */ eth = (__u8 *) skb_push(skb, 14); @@ -2959,7 +2958,7 @@ static struct sk_buff *fill_packet_ipv6(struct net_device *odev, mod_cur_headers(pkt_dev); queue_map = pkt_dev->cur_queue_map; - skb = pktgen_alloc_skb(odev, pkt_dev, 16); + skb = pktgen_alloc_skb(odev, pkt_dev); if (!skb) { sprintf(pkt_dev->result, "No memory"); return NULL;
The commit 879c7220e828 ("net: pktgen: Observe needed_headroom of the device") increased the 'pkt_overhead' field value by LL_RESERVED_SPACE. As a side effect the generated packet size, computed as: /* Eth + IPh + UDPh + mpls */ datalen = pkt_dev->cur_pkt_size - 14 - 20 - 8 - pkt_dev->pkt_overhead; is decreased by the same value. The above changed slightly the behavior of existing pktgen users, and made the procfs interface somewhat inconsistent. Fix it by restoring the previous pkt_overhead value and using LL_RESERVED_SPACE as extralen in skb allocation. Also, change pktgen_alloc_skb() to only partially reserve the headroom to allow the caller to prefetch from ll header start. v1 -> v2: - fixed some typos in the comments Fixes: 879c7220e828 ("net: pktgen: Observe needed_headroom of the device") Suggested-by: Ben Greear <greearb@candelatech.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- net/core/pktgen.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-)