Re: [PATCH v3 5/8] virtio/s390: use cacheline aligned airq bit vectors

Christian Borntraeger
2019-06-03T09:10:43Z

On 29.05.19 14:26, Michael Mueller wrote:
> From: Halil Pasic <pasic@linux.ibm.com>
>
> The flag AIRQ_IV_CACHELINE was recently added to airq_iv_create(). Let
> us use it! We actually wanted the vector to span a cacheline all along.

Given that VIRTIO_IV_BITS is (L1_CACHE_BYTES * 8) this makes perfect sense.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>

>
> Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
> Signed-off-by: Michael Mueller <mimu@linux.ibm.com>
> ---
> drivers/s390/virtio/virtio_ccw.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
> index f995798bb025..1da7430f94c8 100644
> --- a/drivers/s390/virtio/virtio_ccw.c
> +++ b/drivers/s390/virtio/virtio_ccw.c
> @@ -216,7 +216,8 @@ static struct airq_info *new_airq_info(void)
> if (!info)
> return NULL;
> rwlock_init(&info->lock);
> - info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR);
> + info->aiv = airq_iv_create(VIRTIO_IV_BITS, AIRQ_IV_ALLOC | AIRQ_IV_PTR
> + | AIRQ_IV_CACHELINE);
> if (!info->aiv) {
> kfree(info);
> return NULL;
>