On Wed, Mar 20, 2013 at 03:01:24PM +0800, Wanlong Gao wrote:
> Add hot cpu notifier to reset the request virtqueue affinity
> when doing cpu hotplug.
>
> Cc: linux-scsi@xxxxxxxxxxxxxxx
> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Signed-off-by: Wanlong Gao <gaowanlong@xxxxxxxxxxxxxx>
> Reviewed-by: Asias He <asias@xxxxxxxxxx>
> ---
> drivers/scsi/virtio_scsi.c | 29 +++++++++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
> diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
> index 13d7672..0ad9017 100644
> --- a/drivers/scsi/virtio_scsi.c
> +++ b/drivers/scsi/virtio_scsi.c
> @@ -110,6 +110,9 @@ struct virtio_scsi {
> /* if the affinity hint is set for virtqueues */
> bool affinity_hint_set;
>
> + /* CPU hotplug notifier */
> + struct notifier_block nb;
> +
> struct virtio_scsi_vq ctrl_vq;
> struct virtio_scsi_vq event_vq;
> struct virtio_scsi_vq req_vqs[];
> @@ -762,6 +765,23 @@ static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
> put_online_cpus();
> }
>
> +static int virtscsi_cpu_callback(struct notifier_block *nfb,
> + unsigned long action, void *hcpu)
> +{
> + struct virtio_scsi *vscsi = container_of(nfb, struct virtio_scsi, nb);
> + switch(action) {
> + case CPU_ONLINE:
> + case CPU_ONLINE_FROZEN:
> + case CPU_DEAD:
> + case CPU_DEAD_FROZEN:
> + __virtscsi_set_affinity(vscsi, true);
> + break;
> + default:
> + break;
> + }
> + return NOTIFY_OK;
> +}
> +
> static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
> struct virtqueue *vq)
> {
> @@ -884,6 +904,13 @@ static int virtscsi_probe(struct virtio_device *vdev)
> if (err)
> goto virtscsi_init_failed;
>
> + vscsi->nb.notifier_call = &virtscsi_cpu_callback;
> + err = register_hotcpu_notifier(&vscsi->nb);
> + if (err) {
> + pr_err("registering cpu notifier failed\n");
> + goto scsi_add_host_failed;
> + }
> +
> cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
> shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
> shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
> @@ -921,6 +948,8 @@ static void virtscsi_remove(struct virtio_device *vdev)
>
> scsi_remove_host(shost);
>
> + unregister_hotcpu_notifier(&vscsi->nb);
> +
> virtscsi_remove_vqs(vdev);
> scsi_host_put(shost);
> }
> --
> 1.8.2.rc2
>
This one does not apply on top of virtio-next + patch 1-4 in this series.
--
Asias
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