> -----Original Message-----
> From: Jakub Kicinski <kuba@xxxxxxxxxx>
> Sent: Friday, April 14, 2023 10:06 PM
> To: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> Cc: linux-hyperv@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; Dexuan Cui
> <decui@xxxxxxxxxxxxx>; KY Srinivasan <kys@xxxxxxxxxxxxx>; Paul Rosswurm
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> davem@xxxxxxxxxxxxx; wei.liu@xxxxxxxxxx; edumazet@xxxxxxxxxx;
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> ast@xxxxxxxxxx; Ajay Sharma <sharmaajay@xxxxxxxxxxxxx>;
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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
