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Date: Wed, 2 Apr 2025 05:46:16 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Taehee Yoo <ap420073@gmail.com>
Cc: davem@davemloft.net, pabeni@redhat.com, edumazet@google.com,
 andrew+netdev@lunn.ch, horms@kernel.org, michael.chan@broadcom.com,
 pavan.chebbi@broadcom.com, ilias.apalodimas@linaro.org, dw@davidwei.uk,
 netdev@vger.kernel.org, kuniyu@amazon.com, sdf@fomichev.me,
 aleksander.lobakin@intel.com
Subject: Re: [RFC net-next 2/2] eth: bnxt: add support rx side device memory
 TCP
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On Wed, 2 Apr 2025 21:09:11 +0900 Taehee Yoo wrote:
> > Do we check if rx copybreak is enabled before allowing ZC to be enabled?
> > We can't copybreak with unreadable memory.  
> 
> For the bnxt driver, only the first page's data is copied by rx-copybreak.
> agg buffers are not affected by rx-copybreak.
> So I think it's okay.
> I tested rx-copybreak+devmem TCP, and it works well.
> 0 ~ 1024 rx-copybreak and from very small MTU to large MTU.

Ah, good point!