[PATCH net v1] net: stmmac: set PP_FLAG_DMA_SYNC_DEV only if XDP is enabled

Paolo Abeni pabeni at redhat.com
Thu Sep 19 03:25:48 PDT 2024


On 9/13/24 13:02, Furong Xu wrote:
> When XDP is not enabled, the page which holds the received buffer
> will be recycled once the buffer is copied into SKB by
> skb_copy_to_linear_data(), then the MAC core will never reuse this
> page any longer. Set PP_FLAG_DMA_SYNC_DEV wastes CPU cycles.
> 
> This patch brings up to 9% noticeable performance improvement on
> certain platforms.
> 
> Fixes: 5fabb01207a2 ("net: stmmac: Add initial XDP support")
> Signed-off-by: Furong Xu <0x1207 at gmail.com>

I'm quite unconvinced that every performance improvement would be 
eligible to be considered a fix.

Reading the code it looks like this change actually addresses a 
regression introduced by the blamed commit, is that correct? If so 
please re-phrase the commit message accordingly.

Thanks,

Paolo




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