search for: rq_num_free

...) just fail in add_recv_xx()? I think this is safe with one caveat -- we can't modify 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

...> I think this is safe with one caveat -- we can't modify > 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 You don't...

...> I think this is safe with one caveat -- we can't modify > 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 You don't...

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