Michael S. Tsirkin
2022-Jul-07 05:09 UTC
[PATCH v2 2/4] virtio_test: move magic number in code as defined constant
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 at sjtu.edu.cn> > --- > 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