From: Stephen Hemminger <stephen@networkplumber.org>
To: Alex Kiselev <kiselev99@gmail.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] release/acquire memory barriers and ring
Date: Fri, 16 Feb 2018 09:58:12 -0800 [thread overview]
Message-ID: <20180216095812.7e634a53@xeon-e3> (raw)
In-Reply-To: <CAMKNYbw7=b69eCM17p8SperLRD86wtKw3iLj1FtG8gL7bUakNg@mail.gmail.com>
On Tue, 13 Feb 2018 22:37:37 +0300
Alex Kiselev <kiselev99@gmail.com> wrote:
> Hi.
>
> I've been wondering should I use a release/acquire memory barrier pair
> in order to be sure that the other thread will see the fully/corrected
> initialized object
> passed to it via a dpdk ring or ring itself is a kind of barrier?
>
> Let's say I have a pseudo code:
>
> Thread1:
> obj = alloc();
> ...
> obj initialization
> ...
>
> ??? fence(memory_order_release); ???
> rte_ring_sp_enqueue(ring, obj)
>
>
> Thread2:
> ??? fence(memory_order_acquire); ???
> rte_ring_sc_dequeue(ring, obj)
>
> Should I use fences in that code?
>
> Thanks.
>
> --
> Alex
Not necessary. Enqueue/dequeue has necessary ordering; it is built
on compare-exchange which has implied barrier.
next prev parent reply other threads:[~2018-02-16 17:58 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-13 19:37 Alex Kiselev
2018-02-13 19:43 ` Alex Kiselev
2018-02-16 17:58 ` Stephen Hemminger [this message]
2018-02-17 13:59 ` Burakov, Anatoly
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180216095812.7e634a53@xeon-e3 \
--to=stephen@networkplumber.org \
--cc=dev@dpdk.org \
--cc=kiselev99@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).