search for: __skb_frag_unref

...correctness. When we allocate a buffer using skb_page_frag_refill, we use get_page/put_page to allocate/free respectively. For example, if the virtqueue_add_inbuf succeeded, we would eventually call put_page either in virtio-net (e.g., page_to_skb for packets <= GOOD_COPY_LEN bytes) or later in __skb_frag_unref and other functions called during dev_kfree_skb. However, an offset rollback does allow the space to be reused by the next allocation, which could be a good optimization. I can do the offset rollback (with a put_page) in the next patchset. What do you think? >> + /* Do not attempt to ad...

...ze) > +{ > + 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)...

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 at rustcorp.com.au> Cc: Michael S. Tsirkin <mst at redhat.com> Cc: Michael Dalton <mwdalton at google.com> Cc: Eric Dumazet

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 at rustcorp.com.au> Cc: Michael S. Tsirkin <mst at redhat.com> Cc: Michael Dalton <mwdalton at google.com> Cc: Eric Dumazet

...; allocate a buffer using skb_page_frag_refill, we use get_page/put_page > to allocate/free respectively. For example, if the virtqueue_add_inbuf > succeeded, we would eventually call put_page either in virtio-net > (e.g., page_to_skb for packets <= GOOD_COPY_LEN bytes) or later in > __skb_frag_unref and other functions called during dev_kfree_skb. > > However, an offset rollback does allow the space to be reused by the next > allocation, which could be a good optimization. I can do the offset > rollback (with a put_page) in the next patchset. What do you think? If you intend to r...

...; allocate a buffer using skb_page_frag_refill, we use get_page/put_page > to allocate/free respectively. For example, if the virtqueue_add_inbuf > succeeded, we would eventually call put_page either in virtio-net > (e.g., page_to_skb for packets <= GOOD_COPY_LEN bytes) or later in > __skb_frag_unref and other functions called during dev_kfree_skb. > > However, an offset rollback does allow the space to be reused by the next > allocation, which could be a good optimization. I can do the offset > rollback (with a put_page) in the next patchset. What do you think? If you intend to r...

On 01/07/2014 01:25 PM, Michael Dalton wrote: > Commit 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag > allocators") changed the mergeable receive buffer size from PAGE_SIZE to > MTU-size, introducing a single-stream regression for benchmarks with large > average packet size. There is no single optimal buffer size for all > workloads. For workloads

On 01/07/2014 01:25 PM, Michael Dalton wrote: > Commit 2613af0ed18a ("virtio_net: migrate mergeable rx buffers to page frag > allocators") changed the mergeable receive buffer size from PAGE_SIZE to > MTU-size, introducing a single-stream regression for benchmarks with large > average packet size. There is no single optimal buffer size for all > workloads. For workloads