From: Madalin-Cristian Bucur <madalin.bucur@nxp.com>
To: David Miller <davem@davemloft.net>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"oss@buserror.net" <oss@buserror.net>,
"ppc@mindchasers.com" <ppc@mindchasers.com>,
"joe@perches.com" <joe@perches.com>,
"pebolle@tiscali.nl" <pebolle@tiscali.nl>,
"joakim.tjernlund@transmode.se" <joakim.tjernlund@transmode.se>
Subject: RE: [PATCH net-next v6 02/10] dpaa_eth: add support for DPAA Ethernet
Date: Mon, 7 Nov 2016 16:32:16 +0000 [thread overview]
Message-ID: <AM4PR04MB1604B2393D5CE6607204800EECA70@AM4PR04MB1604.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <20161107.105500.43380129278294700.davem@davemloft.net>
> -----Original Message-----
> From: David Miller [mailto:davem@davemloft.net]
> Sent: Monday, November 07, 2016 5:55 PM
>
> From: Madalin-Cristian Bucur <madalin.bucur@nxp.com>
> Date: Mon, 7 Nov 2016 15:43:26 +0000
>
> >> From: David Miller [mailto:davem@davemloft.net]
> >> Sent: Thursday, November 03, 2016 9:58 PM
> >>
> >> Why? By clearing this, you disallow an important fundamental way to do
> >> performane testing, via pktgen.
> >
> > The Tx path in DPAA requires one to insert a back-pointer to the skb
> into
> > the Tx buffer. On the Tx confirmation path the back-pointer in the
> buffer
> > is used to release the skb. If Tx buffer is shared we'd alter the back-
> pointer
> > and leak/double free skbs. See also
>
> Then have your software state store an array of SKB pointers, one for each
> TX ring entry, just like every other driver does.
There is no Tx ring in DPAA. Frames are send out on QMan HW queues towards
the FMan for Tx and then received back on Tx confirmation queues for cleanup.
Array traversal would for sure cost more than using the back-pointer. Also,
we can now process confirmations on a different core than the one doing Tx,
we'd have to keep the arrays percpu and force the Tx conf on the same core.
Or add locks.
Madalin
next prev parent reply other threads:[~2016-11-08 7:27 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-02 20:17 [PATCH net-next v6 00/10] dpaa_eth: Add the QorIQ DPAA Ethernet driver Madalin Bucur
2016-11-02 20:17 ` [PATCH net-next v6 01/10] devres: add devm_alloc_percpu() Madalin Bucur
2016-11-02 20:17 ` [PATCH net-next v6 02/10] dpaa_eth: add support for DPAA Ethernet Madalin Bucur
2016-11-03 19:58 ` David Miller
2016-11-04 6:53 ` Coding Style: Reverse XMAS tree declarations ? (was Re: [PATCH net-next v6 02/10] dpaa_eth: add support for DPAA Ethernet) Joe Perches
2016-11-04 11:01 ` Lino Sanfilippo
2016-11-04 15:07 ` Coding Style: Reverse XMAS tree declarations ? David Miller
2016-11-04 17:44 ` Joe Perches
2016-11-04 20:06 ` Lino Sanfilippo
2016-11-07 11:00 ` David Laight
2016-11-04 17:05 ` Coding Style: Reverse XMAS tree declarations ? (was Re: [PATCH net-next v6 02/10] dpaa_eth: add support for DPAA Ethernet) Randy Dunlap
2016-11-04 19:48 ` David VomLehn
2016-11-07 8:05 ` Michael Ellerman
2016-11-07 15:43 ` [PATCH net-next v6 02/10] dpaa_eth: add support for DPAA Ethernet Madalin-Cristian Bucur
2016-11-07 15:55 ` David Miller
2016-11-07 16:32 ` Madalin-Cristian Bucur [this message]
2016-11-07 16:39 ` David Miller
2016-11-07 16:59 ` Madalin-Cristian Bucur
2016-11-09 17:16 ` Madalin-Cristian Bucur
2016-11-09 17:18 ` David Miller
2016-11-07 16:25 ` Joakim Tjernlund
2016-11-02 20:17 ` [PATCH net-next v6 03/10] dpaa_eth: add option to use one buffer pool set Madalin Bucur
2016-11-02 20:17 ` [PATCH net-next v6 04/10] dpaa_eth: add ethtool functionality Madalin Bucur
2016-11-02 20:17 ` [PATCH net-next v6 05/10] dpaa_eth: add ethtool statistics Madalin Bucur
2016-11-02 20:17 ` [PATCH net-next v6 06/10] dpaa_eth: add sysfs exports Madalin Bucur
2016-11-02 20:17 ` [PATCH net-next v6 07/10] dpaa_eth: add trace points Madalin Bucur
2016-11-02 20:17 ` [PATCH net-next v6 08/10] arch/powerpc: Enable FSL_PAMU Madalin Bucur
2016-11-02 20:17 ` [PATCH net-next v6 09/10] arch/powerpc: Enable FSL_FMAN Madalin Bucur
2016-11-02 20:17 ` [PATCH net-next v6 10/10] arch/powerpc: Enable dpaa_eth Madalin Bucur
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=AM4PR04MB1604B2393D5CE6607204800EECA70@AM4PR04MB1604.eurprd04.prod.outlook.com \
--to=madalin.bucur@nxp.com \
--cc=davem@davemloft.net \
--cc=joakim.tjernlund@transmode.se \
--cc=joe@perches.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=netdev@vger.kernel.org \
--cc=oss@buserror.net \
--cc=pebolle@tiscali.nl \
--cc=ppc@mindchasers.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).