| Message ID | 1383220027-12278-1-git-send-email-jasowang@redhat.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, 2013-10-31 at 19:47 +0800, Jason Wang wrote: > Sometimes we need to coalesce the rx frags to avoid frag list. One example is > virtio-net driver which tries to use small frags for both MTU sized packet and > GSO packet. So this patch introduce skb_coalesce_rx_frag() to do this. > > Cc: Rusty Russell <rusty@rustcorp.com.au> > Cc: Michael S. Tsirkin <mst@redhat.com> > Cc: Michael Dalton <mwdalton@google.com> > Cc: Eric Dumazet <edumazet@google.com> > Acked-by: Michael S. Tsirkin <mst@redhat.com> > Signed-off-by: Jason Wang <jasowang@redhat.com> > --- > Changes from V1: > - remove the useless off parameter. > --- > include/linux/skbuff.h | 3 +++ > net/core/skbuff.c | 13 +++++++++++++ > 2 files changed, 16 insertions(+) > > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > index 2c15497..fffaeaf 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -1372,6 +1372,9 @@ static inline void skb_fill_page_desc(struct sk_buff *skb, int i, > void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, > int size, unsigned int truesize); > > +void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, > + unsigned int truesize); > + > #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags) > #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb)) > #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > index 0ab32fa..87670e1 100644 > --- a/net/core/skbuff.c > +++ b/net/core/skbuff.c > @@ -476,6 +476,19 @@ void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, > } > EXPORT_SYMBOL(skb_add_rx_frag); > > +void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, > + unsigned int truesize) > +{ > + skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; > + > + skb_frag_size_add(frag, size); > + skb->len += size; > + skb->data_len += size; > + skb->truesize += truesize; > + skb_frag_unref(skb, i); This unref is not logical, or should at least be __skb_frag_unref(frag); But I do think this is best done in the caller. In virtio_net this would be a : put_page(page); In tcp stack we do almost the same, but we take the reference on the page if we could not coalesce with prio frag, instead of doing a get and put in the other case. if (can_coalesce) { skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); } else { get_page(page); skb_fill_page_desc(skb, i, page, offset, copy); } > +} > +EXPORT_SYMBOL(skb_coalesce_rx_frag); > + > static void skb_drop_list(struct sk_buff **listp) > { > kfree_skb_list(*listp); -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 10/31/2013 10:26 PM, Eric Dumazet wrote: > On Thu, 2013-10-31 at 19:47 +0800, Jason Wang wrote: >> Sometimes we need to coalesce the rx frags to avoid frag list. One example is >> virtio-net driver which tries to use small frags for both MTU sized packet and >> GSO packet. So this patch introduce skb_coalesce_rx_frag() to do this. >> >> Cc: Rusty Russell <rusty@rustcorp.com.au> >> Cc: Michael S. Tsirkin <mst@redhat.com> >> Cc: Michael Dalton <mwdalton@google.com> >> Cc: Eric Dumazet <edumazet@google.com> >> Acked-by: Michael S. Tsirkin <mst@redhat.com> >> Signed-off-by: Jason Wang <jasowang@redhat.com> >> --- >> Changes from V1: >> - remove the useless off parameter. >> --- >> include/linux/skbuff.h | 3 +++ >> net/core/skbuff.c | 13 +++++++++++++ >> 2 files changed, 16 insertions(+) >> >> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h >> index 2c15497..fffaeaf 100644 >> --- a/include/linux/skbuff.h >> +++ b/include/linux/skbuff.h >> @@ -1372,6 +1372,9 @@ static inline void skb_fill_page_desc(struct sk_buff *skb, int i, >> void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, >> int size, unsigned int truesize); >> >> +void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, >> + unsigned int truesize); >> + >> #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags) >> #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb)) >> #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) >> diff --git a/net/core/skbuff.c b/net/core/skbuff.c >> index 0ab32fa..87670e1 100644 >> --- a/net/core/skbuff.c >> +++ b/net/core/skbuff.c >> @@ -476,6 +476,19 @@ void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, >> } >> EXPORT_SYMBOL(skb_add_rx_frag); >> >> +void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, >> + unsigned int truesize) >> +{ >> + skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; >> + >> + skb_frag_size_add(frag, size); >> + skb->len += size; >> + skb->data_len += size; >> + skb->truesize += truesize; > >> + skb_frag_unref(skb, i); > This unref is not logical, or should at least be > > __skb_frag_unref(frag); > > But I do think this is best done in the caller. > > In virtio_net this would be a : > > put_page(page); > > In tcp stack we do almost the same, but we take the reference on the > page if we could not coalesce with prio frag, instead of doing a get and > put in the other case. > > if (can_coalesce) { > skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); > } else { > get_page(page); > skb_fill_page_desc(skb, i, page, offset, copy); > } > Ok, get it. Will do a put_page() in V3. Thanks >> +} >> +EXPORT_SYMBOL(skb_coalesce_rx_frag); >> + >> static void skb_drop_list(struct sk_buff **listp) >> { >> kfree_skb_list(*listp); > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 2c15497..fffaeaf 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1372,6 +1372,9 @@ static inline void skb_fill_page_desc(struct sk_buff *skb, int i, void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, int size, unsigned int truesize); +void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, + unsigned int truesize); + #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags) #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb)) #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 0ab32fa..87670e1 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -476,6 +476,19 @@ void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, } EXPORT_SYMBOL(skb_add_rx_frag); +void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size, + unsigned int truesize) +{ + skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; + + skb_frag_size_add(frag, size); + skb->len += size; + skb->data_len += size; + skb->truesize += truesize; + skb_frag_unref(skb, i); +} +EXPORT_SYMBOL(skb_coalesce_rx_frag); + static void skb_drop_list(struct sk_buff **listp) { kfree_skb_list(*listp);