[dpdk-dev] [PATCH] rte_ethdev: fix unsafe memory access by calling RX callback.(Internet mail)

[Stephen Hemminger]

On Wed, 4 Mar 2020 16:38:13 +0000
tgw_team(腾讯网关团队) <tgw_team at tencent.com> wrote:

> Sorry, I`ll use a real name in patch v2.
> 
> I don't think this is a TOCTOU question.
> The original code works fine when compiled with the -O3 option.
> At this point the compiler will optimize to one memory access.
> But when compiled with -O0, there will be two memory accesses, which is wrong.
> This change was modified with reference to the rte_eth_tx_burst function.

There is nothing C standard that says compiler has to do it either way.
The optimizer may decide to do two memory accesses or one.
Depending on that in anyway is bad practice.