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

[cuitao]

Sorry, maybe I'm wrong.

I wonder if the gfp parameter in static inline void *kmalloc(size_t s, 
gfp_t gfp) can be deleted if it is not used.

Or would be better to move memset to kmalloc.

Like this:
#define __GFP_ZERO 0x1
static inline void *kmalloc(size_t s, gfp_t gfp)
{
    void *p;
    if (__kmalloc_fake)
        return __kmalloc_fake;

    p = malloc(s);
    if (!p)
            return p;

    if (gfp & __GFP_ZERO)
        memset(p, 0, s);
    return p;
}

在 2024/6/6 15:18, Michael S. Tsirkin 写道:
> 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