unimore/kernel-hacking-2024-linux-steffo
unimore/kernel-hacking-2024-linux-steffo
1
Fork 0
Code Pull requests 5 Wiki Activity

vdpa/mlx5: Parallelize device resume

Browse source 
Currently device resume works on vqs serially. Building up on previous
changes that converted vq operations to the async api, this patch
parallelizes the device resume.

For 1 vDPA device x 32 VQs (16 VQPs) attached to a large VM (256 GB RAM,
32 CPUs x 2 threads per core), the device resume time is reduced from
~16 ms to ~4.5 ms.

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Acked-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20240816090159.1967650-8-dtatulea@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Lei Yang <leiyang@redhat.com>
This commit is contained in:
Dragos Tatulea 2024-08-16 12:01:56 +03:00 committed by Michael S. Tsirkin
parent dcf3eac01f
commit 5eb8c7eb1e
1 changed files with 14 additions and 26 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

40
drivers/vdpa/mlx5/net/mlx5_vnet.c
View file

@ -1675,10 +1675,15 @@ static int suspend_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mv
return suspend_vqs(ndev, mvq->index, 1);
}
static int resume_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
static int resume_vqs(struct mlx5_vdpa_net *ndev, int start_vq, int num_vqs)
{
struct mlx5_vdpa_virtqueue *mvq;
int err;
if (start_vq >= ndev->mvdev.max_vqs)
return -EINVAL;
mvq = &ndev->vqs[start_vq];
if (!mvq->initialized)
return 0;
@ -1690,13 +1695,9 @@ static int resume_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq
/* Due to a FW quirk we need to modify the VQ fields first then change state.
* This should be fixed soon. After that, a single command can be used.
*/
err = modify_virtqueues(ndev, mvq->index, 1, mvq->fw_state);
if (err) {
mlx5_vdpa_err(&ndev->mvdev,
"modify vq properties failed for vq %u, err: %d\n",
mvq->index, err);
err = modify_virtqueues(ndev, start_vq, num_vqs, mvq->fw_state);
if (err)
return err;
}
break;
case MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND:
if (!is_resumable(ndev)) {
@ -1712,25 +1713,12 @@ static int resume_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq
return -EINVAL;
}
err = modify_virtqueues(ndev, mvq->index, 1, MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY);
if (err)
mlx5_vdpa_err(&ndev->mvdev, "modify to resume failed for vq %u, err: %d\n",
mvq->index, err);
return err;
return modify_virtqueues(ndev, start_vq, num_vqs, MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY);
}
static int resume_vqs(struct mlx5_vdpa_net *ndev)
static int resume_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
{
int err = 0;
for (int i = 0; i < ndev->cur_num_vqs; i++) {
int local_err = resume_vq(ndev, &ndev->vqs[i]);
err = local_err ? local_err : err;
}
return err;
return resume_vqs(ndev, mvq->index, 1);
}
static void teardown_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
@ -3080,7 +3068,7 @@ static int mlx5_vdpa_change_map(struct mlx5_vdpa_dev *mvdev,
return err;
}
resume_vqs(ndev);
resume_vqs(ndev, 0, ndev->cur_num_vqs);
return 0;
}
@ -3204,7 +3192,7 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status)
teardown_vq_resources(ndev);
if (ndev->setup) {
err = resume_vqs(ndev);
err = resume_vqs(ndev, 0, ndev->cur_num_vqs);
if (err) {
mlx5_vdpa_warn(mvdev, "failed to resume VQs\n");
goto err_driver;
@ -3628,7 +3616,7 @@ static int mlx5_vdpa_resume(struct vdpa_device *vdev)
down_write(&ndev->reslock);
mvdev->suspended = false;
err = resume_vqs(ndev);
err = resume_vqs(ndev, 0, ndev->cur_num_vqs);
register_link_notifier(ndev);
up_write(&ndev->reslock);