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Date: Wed, 6 Mar 2024 09:41:33 -0800
From: Jakub Kicinski <kuba@kernel.org>
To: Dragos Tatulea <dtatulea@nvidia.com>
Cc: "almasrymina@google.com" <almasrymina@google.com>, "davem@davemloft.net"
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Subject: Re: [RFC] net: esp: fix bad handling of pages from page_pool
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On Wed, 6 Mar 2024 17:09:57 +0000 Dragos Tatulea wrote:
> > Does the caller need to check skb->pp_recycle? pp_recycle seems like a
> > redundant bit. We can tell whether the page is pp by checking
> > is_pp_page(page). the pages in the frag must be pp pages when
> > skb->pp_recycle is set and must be non pp pages when the
> > skb->pp_recycle is not set, so it all seems redundant to me.
> >   
> AFAIU we don't have to check for pp_recycle, at least not in this specific case.

Definitely not something we assuming in a fix that needs to go 
to stable.

So far, AFAIU, it's legal to have an skb without skb->pp_recycle
set, which holds full page refs to a PP page.