search for: virtioqueu

...ee if the nit that Erichas pointed out affects your results. It is also worth noting that we may want to tune the queue sizes for your benchmarks, e.g, by reducing buffer size from 4KB to MTU-sized but keeping queue length constant, we're implicitly decreasing the number of bytes stored in the VirtioQueue for the VirtioNet device, so increasing the queue size may help. Best, Mike

...ee if the nit that Erichas pointed out affects your results. It is also worth noting that we may want to tune the queue sizes for your benchmarks, e.g, by reducing buffer size from 4KB to MTU-sized but keeping queue length constant, we're implicitly decreasing the number of bytes stored in the VirtioQueue for the VirtioNet device, so increasing the queue size may help. Best, Mike

The following series applies to net-next. The following series changes the low memory paths in virtio_net to allow the driver to contribute to reclaim when memory is tight. It attempts to rectify some performance problems we've seen where the network performance drops significantly when memory is low. The working theory is that while the driver contributes to memory pressure when throughput

The following series applies to net-next. The following series changes the low memory paths in virtio_net to allow the driver to contribute to reclaim when memory is tight. It attempts to rectify some performance problems we've seen where the network performance drops significantly when memory is low. The working theory is that while the driver contributes to memory pressure when throughput

...signed int i, avail; + int head; + + /* Sanity check */ + if (!desc) { + pr_debug("%s: empty desc table\n", __func__); + return -EINVAL; + } + + START_USE(vq); + + if (unlikely(vq->broken)) { + END_USE(vq); + return -EIO; + } + + if (!vq->vq.num_free) { + pr_debug("%s: the virtioqueue is full\n", __func__); + END_USE(vq); + return -ENOSPC; + } + + /* Map and fill in the indirect table */ + desc_addr = vring_map_single(vq, desc, num * sizeof(struct vring_desc), + DMA_TO_DEVICE); + if (vring_mapping_error(vq, desc_addr)) { + pr_debug("%s: map desc failed\n&qu...

This patch series enhances the existing virtio-balloon with the following new features: 1) fast ballooning: transfer ballooned pages between the guest and host in chunks, instead of one by one; and 2) cmdq: a new virtqueue to send commands between the device and driver. Currently, it supports commands to report memory stats (replace the old statq mechanism) and report guest unused pages. Liang Li

This patch series enhances the existing virtio-balloon with the following new features: 1) fast ballooning: transfer ballooned pages between the guest and host in chunks, instead of one by one; and 2) cmdq: a new virtqueue to send commands between the device and driver. Currently, it supports commands to report memory stats (replace the old statq mechanism) and report guest unused pages. Liang Li

The virtio_net driver's mergeable receive buffer allocator uses 4KB packet buffers. For MTU-sized traffic, SKB truesize is > 4KB but only ~1500 bytes of the buffer is used to store packet data, reducing the effective TCP window size substantially. This patch addresses the performance concerns with mergeable receive buffers by allocating MTU-sized packet buffers using page frag allocators.

The virtio_net driver's mergeable receive buffer allocator uses 4KB packet buffers. For MTU-sized traffic, SKB truesize is > 4KB but only ~1500 bytes of the buffer is used to store packet data, reducing the effective TCP window size substantially. This patch addresses the performance concerns with mergeable receive buffers by allocating MTU-sized packet buffers using page frag allocators.

...sc) { > + pr_debug("%s: empty desc table\n", __func__); > + return -EINVAL; > + } > + > + START_USE(vq); > + > + if (unlikely(vq->broken)) { > + END_USE(vq); > + return -EIO; > + } > + > + if (!vq->vq.num_free) { > + pr_debug("%s: the virtioqueue is full\n", __func__); > + END_USE(vq); > + return -ENOSPC; > + } > + > + /* Map and fill in the indirect table */ > + desc_addr = vring_map_single(vq, desc, num * sizeof(struct vring_desc), > + DMA_TO_DEVICE); > + if (vring_mapping_error(vq, desc_addr)) { &g...

...sc) { > + pr_debug("%s: empty desc table\n", __func__); > + return -EINVAL; > + } > + > + START_USE(vq); > + > + if (unlikely(vq->broken)) { > + END_USE(vq); > + return -EIO; > + } > + > + if (!vq->vq.num_free) { > + pr_debug("%s: the virtioqueue is full\n", __func__); > + END_USE(vq); > + return -ENOSPC; > + } > + > + /* Map and fill in the indirect table */ > + desc_addr = vring_map_single(vq, desc, num * sizeof(struct vring_desc), > + DMA_TO_DEVICE); > + if (vring_mapping_error(vq, desc_addr)) { &g...