Re: [PATCH] tools/virtio: Use the __GFP_ZERO flag of kmalloc to complete the memory initialization.

From: Michael S. Tsirkin
Date: Thu Jun 06 2024 - 03:18:57 EST


On Wed, Jun 05, 2024 at 09:52:45PM +0800, cuitao wrote:
> Use the __GFP_ZERO flag of kmalloc to initialize memory while allocating it,
> without the need for an additional memset call.
>
> Signed-off-by: cuitao <cuitao@xxxxxxxxxx>
> ---
> tools/virtio/linux/kernel.h | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/tools/virtio/linux/kernel.h b/tools/virtio/linux/kernel.h
> index 6702008f7f5c..9e401fb7c215 100644
> --- a/tools/virtio/linux/kernel.h
> +++ b/tools/virtio/linux/kernel.h
> @@ -66,10 +66,7 @@ static inline void *kmalloc_array(unsigned n, size_t s, gfp_t gfp)
>
> static inline void *kzalloc(size_t s, gfp_t gfp)
> {
> - void *p = kmalloc(s, gfp);
> -
> - memset(p, 0, s);
> - return p;
> + return kmalloc(s, gfp | __GFP_ZERO);
> }


Why do we care? It's just here to make things compile. The simpler the
better.

> static inline void *alloc_pages_exact(size_t s, gfp_t gfp)
> --
> 2.25.1