On Thu, Jul 07, 2022 at 10:44:07AM +0800, Guo Zhi wrote:
> We should avoid using magic numbers directly.
Not necessarily. For repeated values - I guess.
But this kind of thing:
#define BUF_SIZE 1024
int buf_size = BUF_SIZE;
brings no benefit IMHO.
And this has cost - values are now removed from code.
> Signed-off-by: Guo Zhi <qtxuning1999@xxxxxxxxxxx>
> ---
> tools/virtio/virtio_test.c | 18 +++++++++++-------
> 1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
> index 95f78b311..1ecd64271 100644
> --- a/tools/virtio/virtio_test.c
> +++ b/tools/virtio/virtio_test.c
> @@ -20,7 +20,10 @@
> #include "../../drivers/vhost/test.h"
>
> #define RANDOM_BATCH -1
> -
> +#define ALIGN 4096
> +#define RINGSIZE 256
> +#define TEST_BUF_NUM 0x100000
> +#define BUF_SIZE 1024
> /* Unused */
> void *__kmalloc_fake, *__kfree_ignore_start, *__kfree_ignore_end;
>
> @@ -100,8 +103,8 @@ static void vq_reset(struct vq_info *info, int num, struct virtio_device *vdev)
> if (info->vq)
> vring_del_virtqueue(info->vq);
>
> - memset(info->ring, 0, vring_size(num, 4096));
> - vring_init(&info->vring, num, info->ring, 4096);
> + memset(info->ring, 0, vring_size(num, ALIGN));
> + vring_init(&info->vring, num, info->ring, ALIGN);
> info->vq = __vring_new_virtqueue(info->idx, info->vring, vdev, true,
> false, vq_notify, vq_callback, "test");
> assert(info->vq);
> @@ -115,7 +118,7 @@ static void vq_info_add(struct vdev_info *dev, int num)
> info->idx = dev->nvqs;
> info->kick = eventfd(0, EFD_NONBLOCK);
> info->call = eventfd(0, EFD_NONBLOCK);
> - r = posix_memalign(&info->ring, 4096, vring_size(num, 4096));
> + r = posix_memalign(&info->ring, PAGE_SIZE, vring_size(num, ALIGN));
> assert(r >= 0);
> vq_reset(info, num, &dev->vdev);
> vhost_vq_setup(dev, info);
This is actually doing more than what commit log says.
> @@ -131,7 +134,7 @@ static void vdev_info_init(struct vdev_info* dev, unsigned long long features)
> dev->vdev.features = features;
> INIT_LIST_HEAD(&dev->vdev.vqs);
> spin_lock_init(&dev->vdev.vqs_list_lock);
> - dev->buf_size = 1024;
> + dev->buf_size = BUF_SIZE;
This seems to have zero added value.
> dev->buf = malloc(dev->buf_size);
> assert(dev->buf);
> dev->control = open("/dev/vhost-test", O_RDWR);
> @@ -396,7 +399,8 @@ int main(int argc, char **argv)
>
> done:
> vdev_info_init(&dev, features);
> - vq_info_add(&dev, 256);
> - run_test(&dev, &dev.vqs[0], delayed, batch, reset, 0x100000);
> + vq_info_add(&dev, RINGSIZE);
> +
> + run_test(&dev, &dev.vqs[0], delayed, batch, reset, TEST_BUF_NUM);
> return 0;
This replacement does not buy us anything either.
> }
> --
> 2.17.1
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