From: "Liang, Ma" <liang.j.ma@intel.com>
To: "Van Haaren, Harry" <harry.van.haaren@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
"Jain, Deepak K" <deepak.k.jain@intel.com>,
"Geary, John" <john.geary@intel.com>,
"Mccarthy, Peter" <peter.mccarthy@intel.com>,
"jerin.jacob@caviumnetworks.com" <jerin.jacob@caviumnetworks.com>
Subject: Re: [dpdk-dev] [PATCH] event/opdl: fix atomic queue race condition issue
Date: Mon, 26 Mar 2018 14:32:36 +0100 [thread overview]
Message-ID: <20180326133236.GA18416@sivswdev01.ir.intel.com> (raw)
In-Reply-To: <E923DB57A917B54B9182A2E928D00FA65E0173E2@IRSMSX101.ger.corp.intel.com>
On 26 Mar 05:29, Van Haaren, Harry wrote:
> > From: Ma, Liang J
> > Sent: Tuesday, March 13, 2018 11:34 AM
> > To: jerin.jacob@caviumnetworks.com
> > Cc: dev@dpdk.org; Van Haaren, Harry <harry.van.haaren@intel.com>; Jain, Deepak
> > K <deepak.k.jain@intel.com>; Geary, John <john.geary@intel.com>; Mccarthy,
> > Peter <peter.mccarthy@intel.com>
> > Subject: [PATCH] event/opdl: fix atomic queue race condition issue
> >
> > If application link one atomic queue to multiple ports,
> > and each worker core update flow_id, there will have a
> > chance to hit race condition issue and lead to double processing
> > same event. This fix solve the problem and eliminate
> > the race condition issue.
> >
> > Fixes: 4236ce9bf5bf ("event/opdl: add OPDL ring infrastructure library")
> >
>
> General notes
> - Spaces around & % << >> and other bitwise manipulations (https://dpdk.org/doc/guides/contributing/coding_style.html#operators)
> - I've noted a few below, but there are more
> - Usually checkpatch flags these - I'm curious why it didn't in this case
>
> It would be nice if we didn't have to rely on __atomic_load_n() and friends,
> however I don't see a better alternative. Given other DPDK components are
> also using __atomic_* functions, no objection here.
>
>
> <snip>
>
> > @@ -520,7 +528,17 @@ opdl_stage_claim_singlethread(struct opdl_stage *s, void
> > *entries,
> >
> > for (j = 0; j < num_entries; j++) {
> > ev = (struct rte_event *)get_slot(t, s->head+j);
> > - if ((ev->flow_id%s->nb_instance) == s->instance_id) {
>
> Spaces around the %
>
> > +
> > + event = __atomic_load_n(&(ev->event),
> > + __ATOMIC_ACQUIRE);
> > +
> > + opa_id = OPDL_OPA_MASK&(event>>OPDL_OPA_OFFSET);
>
> Spaces &
>
> > + flow_id = OPDL_FLOWID_MASK&event;
>
> Spaces &
>
> > +
> > + if (opa_id >= s->queue_id)
> > + continue;
> > +
> > + if ((flow_id%s->nb_instance) == s->instance_id) {
>
> Spaces %
>
> <snip rest of patch>
>
>
> Will re-review v2. Cheers, -Harry
Thanks, I will send V2 later.
next prev parent reply other threads:[~2018-03-26 13:32 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-13 11:34 Liang Ma
2018-03-26 12:29 ` Van Haaren, Harry
2018-03-26 13:32 ` Liang, Ma [this message]
2018-03-27 14:18 ` [dpdk-dev] [PATCH v2] " Liang Ma
2018-03-29 14:48 ` Van Haaren, Harry
2018-04-02 4:09 ` Jerin Jacob
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=20180326133236.GA18416@sivswdev01.ir.intel.com \
--to=liang.j.ma@intel.com \
--cc=deepak.k.jain@intel.com \
--cc=dev@dpdk.org \
--cc=harry.van.haaren@intel.com \
--cc=jerin.jacob@caviumnetworks.com \
--cc=john.geary@intel.com \
--cc=peter.mccarthy@intel.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).