diff options
| author | Xuan Zhuo <xuanzhuo@linux.alibaba.com> | 2024-10-29 16:46:14 +0800 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2024-11-05 11:37:40 +0100 |
| commit | 47008bb51c3e11c187dacc17af334bdca97c2dca (patch) | |
| tree | a02b82d3a2ddb7199aad0efeb4f1ecafe5c439ac | |
| parent | a33f3df850750216f432b637a5020ad6a740cac1 (diff) | |
virtio_net: enable premapped mode for merge and small by default
Currently, the virtio core will perform a dma operation for each
buffer. Although, the same page may be operated multiple times.
In premapped mod, we can perform only one dma operation for the pages of
the alloc frag. This is beneficial for the iommu device.
kernel command line: intel_iommu=on iommu.passthrough=0
| strict=0 | strict=1
Before | 775496pps | 428614pps
After | 1109316pps | 742853pps
In the 6.11, we disabled this feature because a regress [1].
Now, we fix the problem and re-enable it.
[1]: http://lore.kernel.org/all/8b20cc28-45a9-4643-8e87-ba164a540c0a@oracle.com
Tested-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | drivers/net/virtio_net.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index b82f6b8a8231..befc30b3abb1 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -6107,6 +6107,17 @@ err_ctrl: return -ENOMEM; } +static void virtnet_rq_set_premapped(struct virtnet_info *vi) +{ + int i; + + for (i = 0; i < vi->max_queue_pairs; i++) { + /* error should never happen */ + BUG_ON(virtqueue_set_dma_premapped(vi->rq[i].vq)); + vi->rq[i].do_dma = true; + } +} + static int init_vqs(struct virtnet_info *vi) { int ret; @@ -6120,6 +6131,10 @@ static int init_vqs(struct virtnet_info *vi) if (ret) goto err_free; + /* disable for big mode */ + if (!vi->big_packets || vi->mergeable_rx_bufs) + virtnet_rq_set_premapped(vi); + cpus_read_lock(); virtnet_set_affinity(vi); cpus_read_unlock(); |