From: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
To: gowrishankar muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>, Kumar A S <kumaras@chelsio.com>,
Nirranjan Kirubaharan <nirranjan@chelsio.com>
Subject: Re: [dpdk-dev] Segfault seen in netmap_compat app on Power8
Date: Wed, 12 Apr 2017 12:21:00 +0530 [thread overview]
Message-ID: <20170412065058.GA31224@chelsio.com> (raw)
In-Reply-To: <7fcc232b-4226-d7cc-0df6-b6cb72679713@linux.vnet.ibm.com>
On Thursday, April 04/06/17, 2017 at 15:06:03 +0530, gowrishankar muthukrishnan wrote:
> With gcc 6.3.0, I find this app functioning w/o crash.
>
> Did disabling gcc optimization help ? (set EXTRA_CFLAGS='-O0' before
> compile).
>
Yes, with optimization disabled, the app is not hitting the segfault.
Thanks,
Rahul
> Regards,
> Gowrishankar
> On Thursday 06 April 2017 02:34 PM, Rahul Lakkireddy wrote:
> > Hi,
> >
> > For netmap_compat bridge application on Power8, in netmap_regif
> > function, the assignment to nmif->ring_ofs[i] is not getting reflected
> > immediately.
> >
> > As a result, the subsequent call to netmap_ring_setup ends up writing
> > data at wrong offset. This causes segfault in the app.
> >
> > If we print the nmif->ring_ofs[i] after assignment, then, we see the
> > correct offset and application starts fine.
> >
> > So, probably, some kind of barrier or mechanism to flush write is
> > required on Power8?
> >
> > BTW, this was tried with ToT dpdk git tree on RHEL 7.3 having below
> > gcc version:
> >
> > gcc version 4.8.5 20150623 (Red Hat 4.8.5-11) (GCC)
> >
> > Thanks,
> > Rahul
> >
> >
prev parent reply other threads:[~2017-04-12 6:51 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-06 9:04 Rahul Lakkireddy
2017-04-06 9:36 ` gowrishankar muthukrishnan
2017-04-12 6:51 ` Rahul Lakkireddy [this message]
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=20170412065058.GA31224@chelsio.com \
--to=rahul.lakkireddy@chelsio.com \
--cc=dev@dpdk.org \
--cc=gowrishankar.m@linux.vnet.ibm.com \
--cc=kumaras@chelsio.com \
--cc=nirranjan@chelsio.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).