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From: gowrishankar muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>
To: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>, dev@dpdk.org
Cc: Kumar Sanghvi <kumaras@chelsio.com>,
	Nirranjan Kirubaharan <nirranjan@chelsio.com>
Subject: Re: Segfault seen in netmap_compat app on Power8
Date: Thu, 6 Apr 2017 15:06:03 +0530	[thread overview]
Message-ID: <7fcc232b-4226-d7cc-0df6-b6cb72679713@linux.vnet.ibm.com> (raw)
In-Reply-To: <20170406090413.GA18323@chelsio.com>

With gcc 6.3.0, I find this app functioning w/o crash.

Did disabling gcc optimization help ? (set EXTRA_CFLAGS='-O0' before 
compile).

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
>
>

  reply	other threads:[~2017-04-06  9:36 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-06  9:04 Segfault seen in netmap_compat app on Power8 Rahul Lakkireddy
2017-04-06  9:36 ` gowrishankar muthukrishnan [this message]
2017-04-12  6:51   ` Rahul Lakkireddy

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