search for: xdp_linearize_pag

...-- drivers/net/virtio_net.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 2396c28c0122..ea1bd4bb326d 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -814,8 +814,13 @@ static struct page *xdp_linearize_page(struct receive_queue *rq, int page_off, unsigned int *len) { - struct page *page = alloc_page(GFP_ATOMIC); + int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + struct page *page; + + if (page_off + *len + tailroom > PAGE_SIZE) + return NULL; + page = al...

...g drivers/net/virtio_net.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 2396c28c0122..ea1bd4bb326d 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -814,8 +814,13 @@ static struct page *xdp_linearize_page(struct receive_queue *rq, int page_off, unsigned int *len) { - struct page *page = alloc_page(GFP_ATOMIC); + int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + struct page *page; + + if (page_off + *len + tailroom > PAGE_SIZE) + return NULL; + page = all...

...ions(+), 8 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index fe4562d..58ad40e 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -483,7 +483,7 @@ static struct sk_buff *receive_big(struct net_device *dev, * anymore. */ static struct page *xdp_linearize_page(struct receive_queue *rq, - u16 num_buf, + u16 *num_buf, struct page *p, int offset, unsigned int *len) @@ -497,7 +497,7 @@ static struct page *xdp_linearize_page(struct receive_queue *rq, memcpy(page_address(page) + page_off, page_address(...

...b/drivers/net/virtio_net.c > > @@ -1245,6 +1245,9 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > > if (!xdp_page) > > goto err_xdp; > > offset = VIRTIO_XDP_HEADROOM; > > + > > + put_page(page); > > the error handling of xdp_linearize_page() does not seems self contained. > Does it not seem better? > 1. if xdp_linearize_page() succesed, call put_page() for first buffer just > as put_page() is call for other buffer > 2. or call virtqueue_get_buf() and put_page() for all the buffer of the packet > so the error han...

...static struct sk_buff *receive_mergeable(struct net_device *dev, > >>> if (!xdp_page) > >>> goto err_xdp; > >>> offset = VIRTIO_XDP_HEADROOM; > >>> + > >>> + put_page(page); > >> > >> the error handling of xdp_linearize_page() does not seems self contained. > >> Does it not seem better? > >> 1. if xdp_linearize_page() succesed, call put_page() for first buffer just > >> as put_page() is call for other buffer > >> 2. or call virtqueue_get_buf() and put_page() for all the buffer of...

We used to do data copy through xdp_linearize_page() for the buffer without sufficient headroom, it brings extra complexity without helping for the performance. So this patch remove it and switch to use generic XDP routine to handle this case. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/net/virtio_net.c | 93 ++++++------...

Hi: This series tries to re-enable XDP_REDIRECT for mergeable buffer which was removed since commit 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"). Main concerns are: - not enough tailroom was reserved which breaks cpumap - complex logic like EWMA and linearizing during XDP processing Fix those by: - reserve enough tailroom during refill - disable EWMA

Hi: This series tries to re-enable XDP_REDIRECT for mergeable buffer which was removed since commit 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"). Main concerns are: - not enough tailroom was reserved which breaks cpumap - complex logic like EWMA and linearizing during XDP processing Fix those by: - reserve enough tailroom during refill - disable EWMA

...case > + * we should copy the packet and reserve enough headroom for this. > + * This would be slow but we at most we can copy times of queue > + * size, this is acceptable. What's more important, this help to > + * avoid resetting. > + */ > +static struct page *xdp_linearize_page(struct receive_queue *rq, > + u16 *num_buf, > + struct page *p, > + int offset, > + int page_off, > + unsigned int *len) > +{ > + struct page *page = alloc_page(GFP_ATOMIC); > + > + if (!page) > + return NULL; > +...

...case > + * we should copy the packet and reserve enough headroom for this. > + * This would be slow but we at most we can copy times of queue > + * size, this is acceptable. What's more important, this help to > + * avoid resetting. > + */ > +static struct page *xdp_linearize_page(struct receive_queue *rq, > + u16 *num_buf, > + struct page *p, > + int offset, > + int page_off, > + unsigned int *len) > +{ > + struct page *page = alloc_page(GFP_ATOMIC); > + > + if (!page) > + return NULL; > +...

On Thu, 1 Mar 2018 11:19:05 +0800 Jason Wang <jasowang at redhat.com> wrote: > We used to do data copy through xdp_linearize_page() for the buffer > without sufficient headroom, it brings extra complexity without > helping for the performance. So this patch remove it and switch to use > generic XDP routine to handle this case. I don't like where this is going. I don't like intermixing the native XDP and ge...

On Thu, 1 Mar 2018 11:19:05 +0800 Jason Wang <jasowang at redhat.com> wrote: > We used to do data copy through xdp_linearize_page() for the buffer > without sufficient headroom, it brings extra complexity without > helping for the performance. So this patch remove it and switch to use > generic XDP routine to handle this case. I don't like where this is going. I don't like intermixing the native XDP and ge...

...than what XDP required. In this case + * we should copy the packet and reserve enough headroom for this. + * This would be slow but we at most we can copy times of queue + * size, this is acceptable. What's more important, this help to + * avoid resetting. + */ +static struct page *xdp_linearize_page(struct receive_queue *rq, + u16 *num_buf, + struct page *p, + int offset, + int page_off, + unsigned int *len) +{ + struct page *page = alloc_page(GFP_ATOMIC); + + if (!page) + return NULL; + + memcpy(page_address(page) + page_off, page_address(p)...

...ers, but many existing devices do not + * support it, and we don't want to bother users who are + * using xdp normally. + */ + if (!xdp_prog->aux->xdp_has_frags && + (*num_buf > 1 || headroom < virtnet_get_headroom(vi))) { + /* linearize data for XDP */ + xdp_page = xdp_linearize_page(rq, num_buf, + *page, offset, + VIRTIO_XDP_HEADROOM, + len); + + if (!xdp_page) + return NULL; + } else if (unlikely(headroom < virtnet_get_headroom(vi))) { + xdp_room = SKB_DATA_ALIGN(VIRTIO_XDP_HEADROOM + + sizeof(struct skb_shared_info)); + if (*len +...

...ot > + * support it, and we don't want to bother users who are > + * using xdp normally. > + */ > + if (!xdp_prog->aux->xdp_has_frags && > + (*num_buf > 1 || headroom < virtnet_get_headroom(vi))) { > + /* linearize data for XDP */ > + xdp_page = xdp_linearize_page(rq, num_buf, > + *page, offset, > + VIRTIO_XDP_HEADROOM, > + len); > + > + if (!xdp_page) > + return NULL; > + } else if (unlikely(headroom < virtnet_get_headroom(vi))) { > + xdp_room = SKB_DATA_ALIGN(VIRTIO_XDP_HEADROOM + > + s...

On Thu, 23 Mar 2023 15:24:38 +0800, Yunsheng Lin <linyunsheng at huawei.com> wrote: > On 2023/3/23 13:40, Jason Wang wrote: > >>> > >>>> > >>>> Also, it seems better to split the xdp_linearize_page() to two functions > >>>> as pskb_expand_head() and __skb_linearize() do, one to expand the headroom, > >>>> the other one to do the linearizing. > >>> > >>> No skb here. > >> > >> I means following the semantics of pskb_expan...

On 2018?03?01? 16:02, Jesper Dangaard Brouer wrote: > On Thu, 1 Mar 2018 11:19:05 +0800 Jason Wang <jasowang at redhat.com> wrote: > >> We used to do data copy through xdp_linearize_page() for the buffer >> without sufficient headroom, it brings extra complexity without >> helping for the performance. So this patch remove it and switch to use >> generic XDP routine to handle this case. > I don't like where this is going. I don't like intermixing the n...

...cording to the commit log of 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"), you said: """ ??? The longer explaination is that receive_mergeable() tries to ??? work-around and satisfy these XDP requiresments e.g. by having a ??? function xdp_linearize_page() that allocates and memcpy RX buffers ??? around (in case packet is scattered across multiple rx buffers).? This ??? does currently satisfy XDP_PASS, XDP_DROP and XDP_TX (but only because ??? we have not implemented bpf_xdp_adjust_tail yet). """ So I consider the tailroom is a...

...cording to the commit log of 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"), you said: """ ??? The longer explaination is that receive_mergeable() tries to ??? work-around and satisfy these XDP requiresments e.g. by having a ??? function xdp_linearize_page() that allocates and memcpy RX buffers ??? around (in case packet is scattered across multiple rx buffers).? This ??? does currently satisfy XDP_PASS, XDP_DROP and XDP_TX (but only because ??? we have not implemented bpf_xdp_adjust_tail yet). """ So I consider the tailroom is a...

...4 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 42 insertions(+), 12 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 9bb9e56..426dcf7 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -504,6 +504,7 @@ static struct page *xdp_linearize_page(struct receive_queue *rq, page_off += *len; while (--*num_buf) { + int tailroom = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); unsigned int buflen; void *buf; int off; @@ -518,7 +519,7 @@ static struct page *xdp_linearize_page(struct receive_queue *rq, /* guard against a misc...