Re: [PATCH vhost v2 10/10] vdpa/mlx5: Parallelize VQ suspend/resume for CVQ MQ command
From: Eugenio Perez Martin <eperezma@redhat.com>
Date: 2024-08-28 12:59:45
Also in:
kvm, lkml
On Fri, Aug 16, 2024 at 11:03 AM Dragos Tatulea [off-list ref] wrote:
change_num_qps() is still suspending/resuming VQs one by one. This change switches to parallel suspend/resume. When increasing the number of queues the flow has changed a bit for simplicity: the setup_vq() function will always be called before resume_vqs(). If the VQ is initialized, setup_vq() will exit early. If the VQ is not initialized, setup_vq() will create it and resume_vqs() will resume it. Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com> Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Acked-by: Eugenio Pérez <eperezma@redhat.com>
quoted hunk ↗ jump to hunk
--- drivers/vdpa/mlx5/net/mlx5_vnet.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-)diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c index d1a01c229110..822092eccb32 100644 --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c@@ -2229,25 +2229,27 @@ static int change_num_qps(struct mlx5_vdpa_dev *mvdev, int newqps) if (err) return err; - for (i = cur_vqs - 1; i >= new_vqs; i--) { - struct mlx5_vdpa_virtqueue *mvq = &ndev->vqs[i]; - - if (is_resumable(ndev)) - suspend_vq(ndev, mvq); - else - teardown_vq(ndev, mvq); + if (is_resumable(ndev)) { + suspend_vqs(ndev, new_vqs, cur_vqs - new_vqs); + } else { + for (i = new_vqs; i < cur_vqs; i++) + teardown_vq(ndev, &ndev->vqs[i]); } ndev->cur_num_vqs = new_vqs; } else { ndev->cur_num_vqs = new_vqs; - for (i = cur_vqs; i < new_vqs; i++) { - struct mlx5_vdpa_virtqueue *mvq = &ndev->vqs[i]; - err = mvq->initialized ? resume_vq(ndev, mvq) : setup_vq(ndev, mvq, true); + for (i = cur_vqs; i < new_vqs; i++) { + err = setup_vq(ndev, &ndev->vqs[i], false); if (err) goto clean_added; } + + err = resume_vqs(ndev, cur_vqs, new_vqs - cur_vqs); + if (err) + goto clean_added; + err = modify_rqt(ndev, new_vqs); if (err) goto clean_added; --2.45.1