search for: mergeable_receive_buf_ctx

...e to short-term, transient changes in packet size. + */ +#define RECEIVE_AVG_WEIGHT 64 + #define VIRTNET_DRIVER_VERSION "1.0.0" struct virtnet_stats { @@ -65,11 +70,30 @@ struct send_queue { char name[40]; }; +/* Per-packet buffer context for mergeable receive buffers. */ +struct mergeable_receive_buf_ctx { + /* Packet buffer base address. */ + void *buf; + + /* Original size of the packet buffer for use in SKB truesize. Does not + * include any padding space used to avoid internal fragmentation. + */ + unsigned int truesize; +}; + /* Internal representation of a receive virtqueue */ struct rece...

...> +#define RECEIVE_AVG_WEIGHT 64 > + > #define VIRTNET_DRIVER_VERSION "1.0.0" > > struct virtnet_stats { > @@ -65,11 +70,30 @@ struct send_queue { > char name[40]; > }; > > +/* Per-packet buffer context for mergeable receive buffers. */ > +struct mergeable_receive_buf_ctx { > + /* Packet buffer base address. */ > + void *buf; > + > + /* Original size of the packet buffer for use in SKB truesize. Does not > + * include any padding space used to avoid internal fragmentation. > + */ > + unsigned int truesize; > +}; > + > /* Internal rep...

...> +#define RECEIVE_AVG_WEIGHT 64 > + > #define VIRTNET_DRIVER_VERSION "1.0.0" > > struct virtnet_stats { > @@ -65,11 +70,30 @@ struct send_queue { > char name[40]; > }; > > +/* Per-packet buffer context for mergeable receive buffers. */ > +struct mergeable_receive_buf_ctx { > + /* Packet buffer base address. */ > + void *buf; > + > + /* Original size of the packet buffer for use in SKB truesize. Does not > + * include any padding space used to avoid internal fragmentation. > + */ > + unsigned int truesize; > +}; > + > /* Internal rep...

...> +#define RECEIVE_AVG_WEIGHT 64 > + > #define VIRTNET_DRIVER_VERSION "1.0.0" > > struct virtnet_stats { > @@ -65,11 +70,30 @@ struct send_queue { > char name[40]; > }; > > +/* Per-packet buffer context for mergeable receive buffers. */ > +struct mergeable_receive_buf_ctx { > + /* Packet buffer base address. */ > + void *buf; > + > + /* Original size of the packet buffer for use in SKB truesize. Does not > + * include any padding space used to avoid internal fragmentation. > + */ > + unsigned int truesize; Don't need full int really, it...

...> +#define RECEIVE_AVG_WEIGHT 64 > + > #define VIRTNET_DRIVER_VERSION "1.0.0" > > struct virtnet_stats { > @@ -65,11 +70,30 @@ struct send_queue { > char name[40]; > }; > > +/* Per-packet buffer context for mergeable receive buffers. */ > +struct mergeable_receive_buf_ctx { > + /* Packet buffer base address. */ > + void *buf; > + > + /* Original size of the packet buffer for use in SKB truesize. Does not > + * include any padding space used to avoid internal fragmentation. > + */ > + unsigned int truesize; Don't need full int really, it...

skb_page_frag_refill currently permits only order-0 page allocs unless GFP_WAIT is used. Change skb_page_frag_refill to attempt higher-order page allocations whether or not GFP_WAIT is used. If memory cannot be allocated, the allocator will fall back to successively smaller page allocs (down to order-0 page allocs). This change brings skb_page_frag_refill in line with the existing page allocation

skb_page_frag_refill currently permits only order-0 page allocs unless GFP_WAIT is used. Change skb_page_frag_refill to attempt higher-order page allocations whether or not GFP_WAIT is used. If memory cannot be allocated, the allocator will fall back to successively smaller page allocs (down to order-0 page allocs). This change brings skb_page_frag_refill in line with the existing page allocation

...rq->mrg_buf_ctx until we know the ring isn't full (otherwise, we clobber an in-use entry). It is safe to modify rq->mrg_buf_ctx after we know that virtqueue_add_inbuf has succeeded. I can remove the rq_num_free check from try_fill_recv, and then modify virtqueue_add_inbuf to use a local mergeable_receive_buf_ctx. Once virtqueue_add_inbuf succeeds, the contents of the local variable can be copied to rq->mrg_buf_ctx[rq->mrg_buf_ctx_head]. Best, Mike

...s often(e.g., netperf benefiting from GSO/GRO), we would be allocating 1 SKB per packet buffer instead of 1 SKB per MAX_SKB_FRAGS buffers. How do you feel about any of the below alternatives: (1) Modify the existing mrg_buf_ctx to chain together free entries We can use the 'buf' pointer in mergeable_receive_buf_ctx to chain together free entries so that we can support OOO completions. This would be similar to how virtio-queue manages free sg entries. (2) Combine the buffer pointer and truesize into a single void* value Your point about there only being a byte needed to encode truesize is spot on, and I think...

...we know the ring isn't full (otherwise, we > clobber an in-use entry). It is safe to modify rq->mrg_buf_ctx > after we know that virtqueue_add_inbuf has succeeded. > > I can remove the rq_num_free check from try_fill_recv, and then > modify virtqueue_add_inbuf to use a local mergeable_receive_buf_ctx. > Once virtqueue_add_inbuf succeeds, the contents of the local variable > can be copied to rq->mrg_buf_ctx[rq->mrg_buf_ctx_head]. > > Best, > > Mike You don't have to fill in ctx before calling add_inbuf, do you? Just fill it afterwards. -- MST

...we know the ring isn't full (otherwise, we > clobber an in-use entry). It is safe to modify rq->mrg_buf_ctx > after we know that virtqueue_add_inbuf has succeeded. > > I can remove the rq_num_free check from try_fill_recv, and then > modify virtqueue_add_inbuf to use a local mergeable_receive_buf_ctx. > Once virtqueue_add_inbuf succeeds, the contents of the local variable > can be copied to rq->mrg_buf_ctx[rq->mrg_buf_ctx_head]. > > Best, > > Mike You don't have to fill in ctx before calling add_inbuf, do you? Just fill it afterwards. -- MST

...uf_mergeable(struct receive_queue *rq, gfp_t gfp) { const unsigned int ring_size = rq->mrg_buf_ctx_size; - const size_t hdr_len = sizeof(struct virtio_net_hdr_mrg_rxbuf); struct page_frag *alloc_frag = &rq->alloc_frag; + struct virtnet_info *vi = rq->vq->vdev->priv; struct mergeable_receive_buf_ctx *ctx; int err; unsigned int len, hole; - len = hdr_len + clamp_t(unsigned int, ewma_read(&rq->mrg_avg_pkt_len), - GOOD_PACKET_LEN, PAGE_SIZE - hdr_len); - len = ALIGN(len, L1_CACHE_BYTES); + /* avg_pkt_len is written only in NAPI rx softirq context. We may + * read avg_pkt_len with...