From mboxrd@z Thu Jan 1 00:00:00 1970
Return-Path: <dev-bounces@dpdk.org>
Received: from dpdk.org (dpdk.org [92.243.14.124])
by inbox.dpdk.org (Postfix) with ESMTP id 4177AA00BE;
Tue, 29 Oct 2019 06:47:23 +0100 (CET)
Received: from [92.243.14.124] (localhost [127.0.0.1])
by dpdk.org (Postfix) with ESMTP id 0213C1BEE0;
Tue, 29 Oct 2019 06:47:23 +0100 (CET)
Received: from mail-il1-f193.google.com (mail-il1-f193.google.com
[209.85.166.193]) by dpdk.org (Postfix) with ESMTP id 0B2981BED7
for <dev@dpdk.org>; Tue, 29 Oct 2019 06:47:22 +0100 (CET)
Received: by mail-il1-f193.google.com with SMTP id s6so6761369iln.0
for <dev@dpdk.org>; Mon, 28 Oct 2019 22:47:21 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025;
h=mime-version:references:in-reply-to:from:date:message-id:subject:to
:cc; bh=ERMVaAvK/PU0xaa5JcP39KU75ECrEq+GvL5IeFaxR6s=;
b=Hn4D8UgSjGjjJQ9KuxiNozpOxOHE+on49QsBJmMqjXYQAYVzRFqIiG94JugUMyRTjt
qITuItWh0NKiUe9kuNoC+cPJSQrRP+lTsuO24dwuG1WTAaZnnCK3UwGsrcA7hdPCo91t
XxfUzqOqMUooTEl11l9GE+mGC6WIi0D5m9WWoy/D1qbvxdEedyutZr+2plHSyZIm0exM
P6B49wkvP5ckOZMOCvpTEU7+sjvQOKDe1GyslJYzQmugf6WXLvhrWgX6gxpb8jH3yvFw
09iW/N8wrWmdeyb46TUX+6Y/QiPq1T01lqOCP0TrBEv6jnqrrZdtW7Vf2wYFBmbwWKiO
q41w==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
d=1e100.net; s=20161025;
h=x-gm-message-state:mime-version:references:in-reply-to:from:date
:message-id:subject:to:cc;
bh=ERMVaAvK/PU0xaa5JcP39KU75ECrEq+GvL5IeFaxR6s=;
b=h9e8Dah8NMWaP13wfJuvKxCo5Bt5CaK4noAefQycSbKvNUZ887KPFgl9CuIeeU2ZaC
hVlgGRTRtO2MLaAbEagycSytwW+TELVZfnyuUxwjWwxzAsy75mEdIPOugj4OdOsm5o5W
hkOJDUapiGNPN4bqD5TvhkrBDAOzLYfa5dGtdLM8cXv113F3OtJeP/IHCXzTnY2Ipr7S
8vMiv4HS97yMleQ2W9XN6exqFqGLNR9Euho0Sp9jqzmQZPSLtMZMZ8UAOmMOcuefk3e9
0o62XJAKa9u88HZHE82aJu7aQOkPzeQuBa41rlH5rxfF5DhMTA8cYf5nG9NExmioCukK
H4iw==
X-Gm-Message-State: APjAAAU3FakKFrBbQ/t4JJ7Puhbj2Qp+5138pVIcWfNxo8JkQxB6lqQA
fAJuAS+4VNrMDjDBBBn68ZNLZOpEEP/LampwuoE=
X-Google-Smtp-Source: APXvYqzv2PwKCtGugOc9O+qE7ysCLMMqAeD+tyTURJ0zlqo+2oNNLtsFdrxHiL+fAbMJsBckSQiBeUFzkzairfnQWfQ=
X-Received: by 2002:a92:99c5:: with SMTP id t66mr15101706ilk.271.1572328041127;
Mon, 28 Oct 2019 22:47:21 -0700 (PDT)
MIME-Version: 1.0
References: <20191015075133.38560-1-haiyue.wang@intel.com>
<1811898.7XjjD7ZjLQ@xps>
<CALBAE1MMo5oQPR9z5b1DszPuNe4UHjXM7B8PsJojJzJp6VFt-g@mail.gmail.com>
<12001140.UMXFOKstgs@xps>
<CALBAE1O-WwGzza9+_W4ar+VE2HQsBbcXp2-cCW=s0ikVBHdTmA@mail.gmail.com>
<E3B9F2FDCB65864C82CD632F23D8AB8773D80CFB@shsmsx102.ccr.corp.intel.com>
<CALBAE1MD91BHJ1ZBTnKwz6kjz9RvC1=ikUfUGdV-qDeWEfa1JQ@mail.gmail.com>
<E3B9F2FDCB65864C82CD632F23D8AB8773D8C0EB@shsmsx102.ccr.corp.intel.com>
<CALBAE1Mg_qxabd9K8JpKZNaNzkbJSFnaZHy1HLJw7V3OBBNtGA@mail.gmail.com>
<E3B9F2FDCB65864C82CD632F23D8AB8773D8C176@shsmsx102.ccr.corp.intel.com>
In-Reply-To: <E3B9F2FDCB65864C82CD632F23D8AB8773D8C176@shsmsx102.ccr.corp.intel.com>
From: Jerin Jacob <jerinjacobk@gmail.com>
Date: Tue, 29 Oct 2019 11:17:04 +0530
Message-ID: <CALBAE1OMJXb-gxFKatavMzjgfenBo_W85KZVDV+tExq9HB0VKw@mail.gmail.com>
To: "Wang, Haiyue" <haiyue.wang@intel.com>
Cc: Thomas Monjalon <thomas@monjalon.net>, "Yigit,
Ferruh" <ferruh.yigit@intel.com>, dpdk-dev <dev@dpdk.org>,
"Ye, Xiaolong" <xiaolong.ye@intel.com>, "Kinsella,
Ray" <ray.kinsella@intel.com>,
"Iremonger, Bernard" <bernard.iremonger@intel.com>, "Sun,
Chenmin" <chenmin.sun@intel.com>,
Andrew Rybchenko <arybchenko@solarflare.com>,
Slava Ovsiienko <viacheslavo@mellanox.com>,
Stephen Hemminger <stephen@networkplumber.org>,
David Marchand <david.marchand@redhat.com>,
Jerin Jacob <jerinj@marvell.com>
Content-Type: text/plain; charset="UTF-8"
Subject: Re: [dpdk-dev] [PATCH v4 1/4] ethdev: add the API for getting burst
mode information
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
<mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
<mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>
On Tue, Oct 29, 2019 at 11:12 AM Wang, Haiyue <haiyue.wang@intel.com> wrote:
>
> > -----Original Message-----
> > From: Jerin Jacob <jerinjacobk@gmail.com>
> > Sent: Tuesday, October 29, 2019 13:20
> > To: Wang, Haiyue <haiyue.wang@intel.com>
> > Cc: Thomas Monjalon <thomas@monjalon.net>; Yigit, Ferruh <ferruh.yigit@intel.com>; dpdk-dev
> > <dev@dpdk.org>; Ye, Xiaolong <xiaolong.ye@intel.com>; Kinsella, Ray <ray.kinsella@intel.com>;
> > Iremonger, Bernard <bernard.iremonger@intel.com>; Sun, Chenmin <chenmin.sun@intel.com>; Andrew
> > Rybchenko <arybchenko@solarflare.com>; Slava Ovsiienko <viacheslavo@mellanox.com>; Stephen Hemminger
> > <stephen@networkplumber.org>; David Marchand <david.marchand@redhat.com>; Jerin Jacob
> > <jerinj@marvell.com>
> > Subject: Re: [dpdk-dev] [PATCH v4 1/4] ethdev: add the API for getting burst mode information
> >
> > On Tue, Oct 29, 2019 at 10:14 AM Wang, Haiyue <haiyue.wang@intel.com> wrote:
> > >
> > > > -----Original Message-----
> > > > From: Jerin Jacob <jerinjacobk@gmail.com>
> > > > Sent: Tuesday, October 29, 2019 11:38
> > > > To: Wang, Haiyue <haiyue.wang@intel.com>
> > > > Cc: Thomas Monjalon <thomas@monjalon.net>; Yigit, Ferruh <ferruh.yigit@intel.com>; dpdk-dev
> > > > <dev@dpdk.org>; Ye, Xiaolong <xiaolong.ye@intel.com>; Kinsella, Ray <ray.kinsella@intel.com>;
> > > > Iremonger, Bernard <bernard.iremonger@intel.com>; Sun, Chenmin <chenmin.sun@intel.com>; Andrew
> > > > Rybchenko <arybchenko@solarflare.com>; Slava Ovsiienko <viacheslavo@mellanox.com>; Stephen
> > Hemminger
> > > > <stephen@networkplumber.org>; David Marchand <david.marchand@redhat.com>; Jerin Jacob
> > > > <jerinj@marvell.com>
> > > > Subject: Re: [dpdk-dev] [PATCH v4 1/4] ethdev: add the API for getting burst mode information
> > > >
> > > > > > > > struct rte_eth_burst_mode {
> > > > > > > > uint64_t options;
> > > > > > > > char dev_specific[128]; /* PMD has specific burst mode information */
> > > > > > > > };
> > > > > > >
> > > > > > > I really don't see how we can have generic flags.
> > > > > > > The flags which are proposed are just matching
> > > > > > > the functions implemented in Intel PMDs.
> > > > > > > And this is a complicate solution.
> > > > > > > Why not just returning a name for the selected Rx/Tx mode?
> > > > > >
> > > > > > +1 only for the name
> > > > > >
> > > > > > Let me clarify my earlier proposal:
> > > > > >
> > > > > > 1) The public ethdev API should return only "string" i.e the flags
> > > > > > SHOULD NOT be exposed as ethdev API
> > > > > > i.e
> > > > > > int rte_eth_tx_burst_mode_name(uint16_t port_id, uint16_t queue_id, char *name);
> > > > > >
> > > > > > 2) The PMD interface to the common code can be following
> > > > > >
> > > > > > struct eth_pmd_burst_mode {
> > > > > > uint64_t options;
> > > > > > char name[128]; /* PMD specific burst mode information */
> > > > > > };
> > > > > >
> > > > > > typedef int (*eth_burst_mode_get_t)(struct rte_eth_dev *dev,
> > > > > > uint16_t queue_id, struct eth_burst_mode *mode)
> > > > > >
> > > > > > 3) The implementation of rte_eth_tx_burst_mode_name() shall do optons
> > > > > > flag to string converion(again internal to common code implemetation)
> > > > > > and concatenate with eth_pmd_burst_mode::name
> > > > > >
> > > > > > This would help to reuse some of the flags to name conversion logic
> > > > > > across all PMDs.
> > > > > > And PMD are free to return eth_pmd_burst_mode::options as zero in
> > > > > > that case final
> > > > > > string only be eth_pmd_burst_mode::name.
> > > > > >
> > > > >
> > > > > In fact, 'rte_eth_burst_mode_option_name' for single option, not
> > > > > for struct eth_pmd_burst_mode::option[s]. Need loop to display them.
> > > >
> > > > I see two issues with the flag approach in public API(Internally for
> > > > common code it fine to avoid code duplication)
> > > >
> > > > 1) We can not standardize all flags when it comes to HW specific
> > > > details. We should NOT pollute public API with HW specific details.
> > >
> > > Currently, no detail to HW NIC specific.
> >
> > Yes. What if I want to add a "String" they represent a specific mode of PMD,
> > so that I know what mode PMD really runs.
> > It is not worth adding a flag for that in public API for HW specific notion.
> > That's the problem.
> >
> > >
> > > > 2) There is a danger if application starts taking any action based on
> > > > flags. It should be only for display purpose so in that case public
> > > > API should be the string to avoid misuse of the API(eventually the app
> > > > will fail on some PMD
> > > > if it takes any action based on the flag)
> > >
> > > These flags are *read only* for information. Can't image how to hack DPDK. ;-)
> >
> > To clarify:
> > If we expose flag say RTE_ETH_BURST_SIMPLE then the application can take
> > some action based on
> > if (flag == RTE_ETH_BURST_SIMPLE)
> > do_some_thing();
> >
> > If the purpose is ONLY for "display" as info then exposing as the string will
> > enable to NOT standardize i.e application can never check based on
> > the string name(as it is not standardized) hence no danger.
> >
> > So what is the purpose of this API? Just display or are you expecting
> > the application can do any action based on this?
>
> Oh, I see. Mainly for showing which burst rx/tx module running:
If so, the public API should be as string to avoid any other interpreation of
flags in application.
And it makes application life easy too.
>
> https://docs.fd.io/vpp/18.11/d7/d1d/plugins_2dpdk_2device_2format_8c_source.html
>
> s = format (s, "%Utx burst function: %s\n",
> 579 format_white_space, indent + 2,
> 580 ptr2sname (rte_eth_devices[xd->port_id].tx_pkt_burst));
> 581 s = format (s, "%Urx burst function: %s\n",
> 582 format_white_space, indent + 2,
> 583 ptr2sname (rte_eth_devices[xd->port_id].rx_pkt_burst));
>
> https://docs.fd.io/vpp/18.11/d7/d1d/plugins_2dpdk_2device_2format_8c_source.html
>
> 488 static const char *
> 489 ptr2sname (void *p)
> 490 {
> 491 Dl_info info = { 0 };
> 492
> 493 if (dladdr (p, &info) == 0)
> 494 return 0;
> 495
> 496 return info.dli_sname;
> 497 }
>
> tx burst function: ixgbe_xmit_pkts
> rx burst function: ixgbe_recv_pkts
>
> If the PMD's rx/tx is *static* function, 'ptr2name' returns 'nil'.