[dpdk-dev] [PATCH v3 1/3] ring: read tail using atomic load

Jerin Jacob jerin.jacob at caviumnetworks.com
Mon Oct 8 14:05:25 CEST 2018


-----Original Message-----
> Date: Mon, 8 Oct 2018 11:59:16 +0000
> From: Ola Liljedahl <Ola.Liljedahl at arm.com>
> To: Jerin Jacob <jerin.jacob at caviumnetworks.com>
> CC: "dev at dpdk.org" <dev at dpdk.org>, Honnappa Nagarahalli
>  <Honnappa.Nagarahalli at arm.com>, "Ananyev, Konstantin"
>  <konstantin.ananyev at intel.com>, "Gavin Hu (Arm Technology China)"
>  <Gavin.Hu at arm.com>, Steve Capper <Steve.Capper at arm.com>, nd <nd at arm.com>,
>  "stable at dpdk.org" <stable at dpdk.org>
> Subject: Re: [PATCH v3 1/3] ring: read tail using atomic load
> user-agent: Microsoft-MacOutlook/10.11.0.180909
> 
> 
> On 08/10/2018, 13:50, "Jerin Jacob" <jerin.jacob at caviumnetworks.com> wrote:
> 
> 
>     I don't know how that creates more undefined behavior. So replied in the
>     context of your reply that, according to your view even Linux is running
>     with undefined behavior.
> 
> As I explained, Linux does not use C11 atomics (nor GCC __atomic builtins) so
> cannot express the kind of undefined behaviour caused by mixing conflicting atomic
> (as defined by the C11 standard) and non-atomic accesses to the same object.
> 
> Checked the latest version from https://github.com/torvalds/linux

Yet another top post. So you removed the complete earlier context. Never
mind.

I am not saying Linux is using C11 atomic. I asked, Can't we follow
like Linux to use the HW feature of load acquire and store release
semantics with introducing C11 memory model.



> 
> 


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