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From: Thomas Monjalon <thomas@monjalon.net>
To: "Van Haaren, Harry" <harry.van.haaren@intel.com>,
	Nithin Dabilpuram <nithind1988@gmail.com>
Cc: Pavan Nikhilesh <pbhagavatula@marvell.com>,
	Jerin Jacob <jerinj@marvell.com>,
	Ruifeng Wang <ruifeng.wang@arm.com>,
	"Richardson, Bruce" <bruce.richardson@intel.com>,
	"Ananyev, Konstantin" <konstantin.ananyev@intel.com>,
	"kirankumark@marvell.com" <kirankumark@marvell.com>,
	"dev@dpdk.org" <dev@dpdk.org>,
	"david.marchand@redhat.com" <david.marchand@redhat.com>,
	"olivier.matz@6wind.com" <olivier.matz@6wind.com>
Subject: Re: [dpdk-dev] [PATCH v4] node: switch IPv4 metadata to dynamic mbuf field
Date: Wed, 28 Oct 2020 11:43:56 +0100
Message-ID: <2588040.FO0brCVOmV@thomas> (raw)
In-Reply-To: <X5lLD/E0eUXkDw68@gmail.com>

28/10/2020 11:42, Nithin Dabilpuram:
> On Wed, Oct 28, 2020 at 10:24:01AM +0000, Van Haaren, Harry wrote:
> > From: Thomas Monjalon
> > > 28/10/2020 10:30, Nithin Dabilpuram:
> > > > From: Thomas Monjalon <thomas@monjalon.net>
> > > >
> > > > The node_mbuf_priv1 was stored in the deprecated mbuf field udata64.
> > > > It is moved to a dynamic field in order to allow removal of udata64.
> > > >
> > > > Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> > > > Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
> > > [...]
> > > > +	IP4_LOOKUP_NODE_PRIV1_OFF(node->ctx) =
> > > node_mbuf_priv1_dynfield_offset;
> > > 
> > > That's interesting.
> > > You copy the offset in the node context for better performance.
> > > How much is it better than with global offset variable?
> > > How much it decreases compared to a static mbuf field?
> > 
> > Also interested in this topic, I'll offer the logical/theory point of view;
> > 
> > With a static field, the offset into the mbuf can be encoded in the instruction
> > stream, meaning there are no d-cache loads to identify particular dynamic field.
> > 
> > With a static/global variable, the cache line where the value resides is presumably
> > not hot in cache per burst (assuming an application that does significant work, so not
> > in cache since last burst). Hence overhead estimate could be 1x cache line load per burst.
> > 
> > With the data copied into the node, the offset is presumably on a hot cache line as the
> > node is using other data-members of its context. As a result, perhaps a cold static cache
> > line load is converted to a hot node-context line re-use. 
> > 
> > Real world overhead likely depends on A) does the application cache-trash enough to make
> > the static/global line fall out of cache - causing perf degradation due to reload, and B) does
> > the node->ctx still fit in the same number of lines as before if the value is copied there.
> 
> Agreed, node->ctx is already referred to get other data (lpm pointer). So
> referening another 4 bytes might even convert that to load pair which is at
> no extra cost.
> 
> Number's wise, 
> it decreases by ~1.4 % from static mbuf field to global offset variable 
> and it decreases by ~1% from static mbuf field to node context field
> cached per process call

OK thanks for providing these numbers.



  reply	other threads:[~2020-10-28 10:44 UTC|newest]

Thread overview: 178+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-26  5:20 [dpdk-dev] [PATCH 00/15] remove mbuf userdata Thomas Monjalon
2020-10-26  5:20 ` [dpdk-dev] [PATCH 01/15] examples: enclose DPDK includes with angle brackets Thomas Monjalon
2020-10-26 14:23   ` Andrew Rybchenko
2020-10-27 11:32   ` Bruce Richardson
2020-10-26  5:20 ` [dpdk-dev] [PATCH 02/15] kni: move header file from EAL Thomas Monjalon
2020-10-26 14:25   ` Andrew Rybchenko
2020-10-27 11:33   ` Bruce Richardson
2020-10-26  5:20 ` [dpdk-dev] [PATCH 03/15] mbuf: fix typo in dynamic field convention note Thomas Monjalon
2020-10-26 14:26   ` Andrew Rybchenko
2020-10-26  5:20 ` [dpdk-dev] [PATCH 04/15] node: switch IPv4 metadata to dynamic mbuf field Thomas Monjalon
2020-10-26 10:40   ` David Marchand
2020-10-26 14:29     ` Thomas Monjalon
2020-10-26 14:34       ` Andrew Rybchenko
2020-10-26 14:39         ` Thomas Monjalon
2020-10-26  5:20 ` [dpdk-dev] [PATCH 05/15] security: switch " Thomas Monjalon
2020-10-26 10:41   ` David Marchand
2020-10-26 14:30     ` Thomas Monjalon
2020-10-26 17:58     ` Akhil Goyal
2020-10-26 15:06   ` Andrew Rybchenko
2020-10-26 16:49     ` Thomas Monjalon
2020-10-26 19:03       ` Thomas Monjalon
2020-10-26  5:20 ` [dpdk-dev] [PATCH 06/15] event/sw: switch test counter " Thomas Monjalon
2020-10-26 15:09   ` Andrew Rybchenko
2020-10-26  5:20 ` [dpdk-dev] [PATCH 07/15] net/ark: ignore user data Thomas Monjalon
2020-10-26  5:20 ` [dpdk-dev] [PATCH 08/15] net/bnxt: switch CFA code to dynamic mbuf field Thomas Monjalon
2020-10-26 10:42   ` David Marchand
2020-10-26 14:32     ` Thomas Monjalon
2020-10-26  5:20 ` [dpdk-dev] [PATCH 09/15] net/vmxnet3: switch MSS hint " Thomas Monjalon
2020-10-26 15:14   ` Andrew Rybchenko
2020-10-26 15:21     ` Andrew Rybchenko
2020-10-26 16:50       ` Thomas Monjalon
2020-10-26 18:13         ` Thomas Monjalon
2020-10-26  5:21 ` [dpdk-dev] [PATCH 10/15] test/distributor: switch sequence " Thomas Monjalon
2020-10-26  9:39   ` Lukasz Wojciechowski
2020-10-26  5:21 ` [dpdk-dev] [PATCH 11/15] test/graph: switch user data " Thomas Monjalon
2020-10-26  5:21 ` [dpdk-dev] [PATCH 12/15] app/eventdev: switch flow ID " Thomas Monjalon
2020-10-26  5:21 ` [dpdk-dev] [PATCH 13/15] examples/bbdev: switch " Thomas Monjalon
2020-10-26  5:21 ` [dpdk-dev] [PATCH 14/15] examples/rxtx_callbacks: " Thomas Monjalon
2020-10-26 10:43   ` David Marchand
2020-10-26 14:33     ` Thomas Monjalon
2020-10-26 14:53       ` Stephen Hemminger
2020-10-26 16:32         ` Thomas Monjalon
2020-10-26  5:21 ` [dpdk-dev] [PATCH 15/15] mbuf: remove userdata field Thomas Monjalon
2020-10-26 22:19 ` [dpdk-dev] [PATCH v2 00/15] remove mbuf userdata Thomas Monjalon
2020-10-26 22:19   ` [dpdk-dev] [PATCH v2 01/15] examples: enclose DPDK includes with angle brackets Thomas Monjalon
2020-10-26 22:20   ` [dpdk-dev] [PATCH v2 02/15] kni: move header file from EAL Thomas Monjalon
2020-10-26 22:20   ` [dpdk-dev] [PATCH v2 03/15] mbuf: fix typo in dynamic field convention note Thomas Monjalon
2020-10-26 22:20   ` [dpdk-dev] [PATCH v2 04/15] node: switch IPv4 metadata to dynamic mbuf field Thomas Monjalon
2020-10-27  9:32     ` Olivier Matz
2020-10-27  9:34       ` Thomas Monjalon
2020-10-27 14:23     ` Nithin Dabilpuram
2020-10-27 14:33       ` Thomas Monjalon
2020-10-27 15:33         ` Nithin Dabilpuram
2020-10-27 15:57           ` Thomas Monjalon
2020-10-27 16:16             ` Nithin Dabilpuram
2020-10-27 16:26               ` Thomas Monjalon
2020-10-28  9:30                 ` [dpdk-dev] [PATCH v4] " Nithin Dabilpuram
2020-10-28 10:08                   ` Thomas Monjalon
2020-10-28 10:24                     ` Van Haaren, Harry
2020-10-28 10:42                       ` Nithin Dabilpuram
2020-10-28 10:43                         ` Thomas Monjalon [this message]
2020-10-28 18:07                       ` Thomas Monjalon
2020-10-29 10:17                         ` Van Haaren, Harry
2020-10-28 10:33                     ` Nithin Dabilpuram
2020-10-26 22:20   ` [dpdk-dev] [PATCH v2 05/15] security: switch " Thomas Monjalon
2020-10-27  2:01     ` Wang, Haiyue
2020-10-27  8:52       ` Thomas Monjalon
2020-10-27 13:12         ` Wang, Haiyue
2020-10-27 10:05     ` Olivier Matz
2020-10-27 16:10       ` Thomas Monjalon
2020-10-26 22:20   ` [dpdk-dev] [PATCH v2 06/15] event/sw: switch test counter " Thomas Monjalon
2020-10-27 10:15     ` Olivier Matz
2020-10-27 16:14       ` Thomas Monjalon
2020-10-26 22:20   ` [dpdk-dev] [PATCH v2 07/15] net/ark: ignore user data Thomas Monjalon
2020-10-27 15:32     ` Ed Czeck
2020-10-27 15:55       ` Thomas Monjalon
2020-10-27 16:05         ` Thomas Monjalon
2020-10-26 22:20   ` [dpdk-dev] [PATCH v2 08/15] net/bnxt: switch CFA code to dynamic mbuf field Thomas Monjalon
2020-10-27  4:44     ` Ajit Khaparde
2020-10-27 10:31     ` Olivier Matz
2020-10-27 16:22       ` Thomas Monjalon
2020-10-26 22:20   ` [dpdk-dev] [PATCH v2 09/15] net/vmxnet3: switch MSS hint " Thomas Monjalon
2020-10-27 10:45     ` Olivier Matz
2020-10-27 16:25       ` Thomas Monjalon
2020-10-26 22:20   ` [dpdk-dev] [PATCH v2 10/15] test/distributor: switch sequence " Thomas Monjalon
2020-10-26 22:20   ` [dpdk-dev] [PATCH v2 11/15] test/graph: switch user data " Thomas Monjalon
2020-10-26 22:20   ` [dpdk-dev] [PATCH v2 12/15] app/eventdev: switch flow ID " Thomas Monjalon
2020-10-26 22:20   ` [dpdk-dev] [PATCH v2 13/15] examples/bbdev: switch " Thomas Monjalon
2020-10-26 22:20   ` [dpdk-dev] [PATCH v2 14/15] examples/rxtx_callbacks: " Thomas Monjalon
2020-10-26 22:20   ` [dpdk-dev] [PATCH v2 15/15] mbuf: remove userdata field Thomas Monjalon
2020-10-27 10:53     ` Olivier Matz
2020-10-27 21:01 ` [dpdk-dev] [PATCH v3 00/15] remove mbuf userdata Thomas Monjalon
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 01/15] examples: enclose DPDK includes with angle brackets Thomas Monjalon
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 02/15] kni: move header file from EAL Thomas Monjalon
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 03/15] mbuf: fix typo in dynamic field convention note Thomas Monjalon
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 04/15] node: switch IPv4 metadata to dynamic mbuf field Thomas Monjalon
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 05/15] security: switch " Thomas Monjalon
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 06/15] event/sw: switch test counter " Thomas Monjalon
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 07/15] net/ark: switch user data " Thomas Monjalon
2020-10-27 22:30     ` Thomas Monjalon
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 08/15] net/bnxt: switch CFA code " Thomas Monjalon
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 09/15] net/vmxnet3: switch MSS hint " Thomas Monjalon
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 10/15] test/distributor: switch sequence " Thomas Monjalon
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 11/15] test/graph: switch user data " Thomas Monjalon
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 12/15] app/eventdev: switch flow ID " Thomas Monjalon
2020-10-28  4:54     ` Jerin Jacob
2020-10-28  7:43       ` Thomas Monjalon
2020-10-28  8:06         ` Jerin Jacob
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 13/15] examples/bbdev: switch " Thomas Monjalon
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 14/15] examples/rxtx_callbacks: " Thomas Monjalon
2020-10-27 21:01   ` [dpdk-dev] [PATCH v3 15/15] mbuf: remove userdata field Thomas Monjalon
2020-10-28 10:26 ` [dpdk-dev] [PATCH v4 00/15] remove mbuf userdata Thomas Monjalon
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 01/15] examples: enclose DPDK includes with angle brackets Thomas Monjalon
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 02/15] kni: move header file from EAL Thomas Monjalon
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 03/15] mbuf: fix typo in dynamic field convention note Thomas Monjalon
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 04/15] node: switch IPv4 metadata to dynamic mbuf field Thomas Monjalon
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 05/15] security: switch " Thomas Monjalon
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 06/15] event/sw: switch test counter " Thomas Monjalon
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 07/15] net/ark: switch user data to dynamic mbuf fields Thomas Monjalon
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 08/15] net/bnxt: switch CFA code to dynamic mbuf field Thomas Monjalon
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 09/15] net/vmxnet3: switch MSS hint " Thomas Monjalon
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 10/15] test/distributor: switch sequence " Thomas Monjalon
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 11/15] test/graph: switch user data " Thomas Monjalon
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 12/15] app/eventdev: switch flow ID " Thomas Monjalon
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 13/15] examples/bbdev: switch " Thomas Monjalon
2020-10-28 11:51     ` Andrew Rybchenko
2020-10-28 12:21       ` Thomas Monjalon
2020-10-28 12:55         ` Andrew Rybchenko
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 14/15] examples/rxtx_callbacks: " Thomas Monjalon
2020-10-28 10:26   ` [dpdk-dev] [PATCH v4 15/15] mbuf: remove userdata field Thomas Monjalon
2020-10-30 17:29 ` [dpdk-dev] [PATCH v5 00/15] remove mbuf userdata Thomas Monjalon
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 01/15] eventdev: remove software Rx timestamp Thomas Monjalon
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 02/15] mbuf: add Rx timestamp dynamic flag Thomas Monjalon
2020-11-01 20:03     ` Andrew Rybchenko
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 03/15] ethdev: register mbuf field and flags for timestamp Thomas Monjalon
2020-11-01 20:10     ` Andrew Rybchenko
2020-11-01 22:54       ` Thomas Monjalon
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 04/15] latency: switch timestamp to dynamic mbuf field Thomas Monjalon
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 05/15] net/ark: " Thomas Monjalon
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 06/15] net/dpaa2: " Thomas Monjalon
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 07/15] net/mlx5: fix dynamic mbuf offset lookup check Thomas Monjalon
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 08/15] net/mlx5: switch timestamp to dynamic mbuf field Thomas Monjalon
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 09/15] net/nfb: " Thomas Monjalon
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 10/15] net/octeontx2: " Thomas Monjalon
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 11/15] net/pcap: " Thomas Monjalon
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 12/15] app/testpmd: " Thomas Monjalon
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 13/15] examples/rxtx_callbacks: switch timestamp to dynamic field Thomas Monjalon
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 14/15] mbuf: remove deprecated timestamp field Thomas Monjalon
2020-11-01 20:13     ` Andrew Rybchenko
2020-10-30 17:29   ` [dpdk-dev] [PATCH v5 15/15] mbuf: move pool pointer in hotter first half Thomas Monjalon
2020-11-01 20:23     ` Andrew Rybchenko
2020-10-30 17:44 ` [dpdk-dev] [PATCH v6 00/15] remove mbuf userdata Thomas Monjalon
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 01/15] examples: enclose DPDK includes with angle brackets Thomas Monjalon
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 02/15] kni: move header file from EAL Thomas Monjalon
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 03/15] mbuf: fix typo in dynamic field convention note Thomas Monjalon
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 04/15] node: switch IPv4 metadata to dynamic mbuf field Thomas Monjalon
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 05/15] security: switch " Thomas Monjalon
2020-10-31  8:56     ` David Marchand
2020-10-31  9:26       ` David Marchand
2020-10-31 14:38       ` Thomas Monjalon
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 06/15] event/sw: switch test counter " Thomas Monjalon
2020-10-30 18:53     ` Van Haaren, Harry
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 07/15] net/ark: switch user data to dynamic mbuf fields Thomas Monjalon
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 08/15] net/bnxt: switch CFA code to dynamic mbuf field Thomas Monjalon
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 09/15] net/vmxnet3: switch MSS hint " Thomas Monjalon
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 10/15] test/distributor: switch sequence " Thomas Monjalon
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 11/15] test/graph: switch user data " Thomas Monjalon
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 12/15] app/eventdev: switch flow ID " Thomas Monjalon
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 13/15] examples/bbdev: switch " Thomas Monjalon
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 14/15] examples/rxtx_callbacks: switch TSC to dynamic field Thomas Monjalon
2020-10-30 17:44   ` [dpdk-dev] [PATCH v6 15/15] mbuf: remove userdata field Thomas Monjalon
2020-10-31 15:07   ` [dpdk-dev] [PATCH v6 00/15] remove mbuf userdata Thomas Monjalon
2020-10-31 23:36     ` Ferruh Yigit
2020-11-01  9:15       ` Thomas Monjalon
2020-11-01 10:26         ` David Marchand
2020-11-02  9:11           ` Jiawen Wu
2020-11-02 11:08             ` Ferruh Yigit
2020-11-02 11:58               ` Ferruh Yigit

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