netdev - Re: [PATCH net-next] gro: avoid checking for a failed search

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Message-ID: <CAJLv34RKj6u_7EZwYWiNujC-R4nxKHJ24DVYqydgHPy88NqMPA@mail.gmail.com>
Date:   Wed, 2 Nov 2022 17:45:27 +0100
From:   Richard Gobert <richardbgobert@...il.com>
To:     Jakub Kicinski <kuba@...nel.org>
Cc:     davem@...emloft.net, edumazet@...gle.com, pabeni@...hat.com,
        lixiaoyan@...gle.com, alexanderduyck@...com,
        steffen.klassert@...unet.com, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH net-next] gro: avoid checking for a failed search

> Why does it matter? You see a measurable perf win?

In the common case, we will exit the loop with a break,
so this patch eliminates an unnecessary check.

On some architectures this optimization might be done
automatically by the compiler, but I think it will be better
to make it explicit here. Although on x86 this optimization
happens automatically, I noticed that on my build target
(ARM/GCC) this does change the binary.