RE: [PATCH V3,net-next, 3/4] net: mana: Enable RX path to handle various MTU sizes

[Haiyang Zhang]

> -----Original Message-----
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> Sent: Friday, April 14, 2023 10:06 PM
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> Subject: Re: [PATCH V3,net-next, 3/4] net: mana: Enable RX path to handle
> various MTU sizes
> 
> On Wed, 12 Apr 2023 14:16:02 -0700 Haiyang Zhang wrote:
> > +	} else if (rxq->alloc_size > PAGE_SIZE) {
> > +		if (is_napi)
> > +			va = napi_alloc_frag(rxq->alloc_size);
> 
> Allocating frag larger than a page is not safe.

 I saw other drivers doing this - use napi_alloc_frag for size bigger than a page.
And it returns compound page. Why it's not safe? Should we use other allocator
when need compound pages?

> Frag allocator falls back to allocating single pages, doesn't it?

Actually I checked it. Compound page is still returned for size smaller than PAGE_SIZE,
so I used single page allocation for that.

Thanks,
- Haiyang