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From: "Samudrala, Sridhar" <sridhar.samudrala@intel.com>
To: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: magnus.karlsson@intel.com, bjorn.topel@intel.com,
	netdev@vger.kernel.org, bpf@vger.kernel.org,
	intel-wired-lan@lists.osuosl.org, maciej.fijalkowski@intel.com,
	tom.herbert@intel.com
Subject: Re: [PATCH bpf-next 0/5] Add support for SKIP_BPF flag for AF_XDP sockets
Date: Thu, 15 Aug 2019 23:25:55 -0700
Message-ID: <f9df4d0e-c5f2-036d-994c-3162274820ea@intel.com> (raw)
In-Reply-To: <20190815122844.52eeda08@cakuba.netronome.com>



On 8/15/2019 12:28 PM, Jakub Kicinski wrote:
> On Wed, 14 Aug 2019 20:46:18 -0700, Sridhar Samudrala wrote:
>> This patch series introduces XDP_SKIP_BPF flag that can be specified
>> during the bind() call of an AF_XDP socket to skip calling the BPF
>> program in the receive path and pass the buffer directly to the socket.
>>
>> When a single AF_XDP socket is associated with a queue and a HW
>> filter is used to redirect the packets and the app is interested in
>> receiving all the packets on that queue, we don't need an additional
>> BPF program to do further filtering or lookup/redirect to a socket.
>>
>> Here are some performance numbers collected on
>>    - 2 socket 28 core Intel(R) Xeon(R) Platinum 8180 CPU @ 2.50GHz
>>    - Intel 40Gb Ethernet NIC (i40e)
>>
>> All tests use 2 cores and the results are in Mpps.
>>
>> turbo on (default)
>> ---------------------------------------------	
>>                        no-skip-bpf    skip-bpf
>> ---------------------------------------------	
>> rxdrop zerocopy           21.9         38.5
>> l2fwd  zerocopy           17.0         20.5
>> rxdrop copy               11.1         13.3
>> l2fwd  copy                1.9          2.0
>>
>> no turbo :  echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo
>> ---------------------------------------------	
>>                        no-skip-bpf    skip-bpf
>> ---------------------------------------------	
>> rxdrop zerocopy           15.4         29.0
>> l2fwd  zerocopy           11.8         18.2
>> rxdrop copy                8.2         10.5
>> l2fwd  copy                1.7          1.7
>> ---------------------------------------------	
> 
> Could you include a third column here - namely the in-XDP performance?
> AFAIU the way to achieve better performance with AF_XDP is to move the
> fast path into the kernel's XDP program..

The in-xdp drop that can be measured with xdp1 is lower than rxdrop
zerocopy with skip-bpf although in-xdp drop uses only 1 core. af-xdp 
1-core performance would improve with need-wakeup or busypoll patches 
and based on early experiments so far af-xdp with need-wakeup/busypoll + 
skip-bpf perf is higher than in-xdp drop.

Will include in-xdp drop data too in the next revision.

> 
> Maciej's work on batching XDP program's execution should lower the
> retpoline overhead, without leaning close to the bypass model.
> 

      reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-15  3:46 Sridhar Samudrala
2019-08-15  3:46 ` [PATCH bpf-next 1/5] xsk: Convert bool 'zc' field in struct xdp_umem to a u32 bitmap Sridhar Samudrala
2019-08-15  3:46 ` [PATCH bpf-next 2/5] xsk: Introduce XDP_SKIP_BPF bind option Sridhar Samudrala
2019-08-15  3:46 ` [PATCH bpf-next 3/5] i40e: Enable XDP_SKIP_BPF option for AF_XDP sockets Sridhar Samudrala
2019-08-16  9:21   ` kbuild test robot
2019-08-15  3:46 ` [PATCH bpf-next 4/5] ixgbe: " Sridhar Samudrala
2019-08-15  3:46 ` [PATCH bpf-next 5/5] xdpsock_user: Add skip_bpf option Sridhar Samudrala
2019-08-15 11:12 ` [PATCH bpf-next 0/5] Add support for SKIP_BPF flag for AF_XDP sockets Toke Høiland-Jørgensen
2019-08-15 16:25   ` Samudrala, Sridhar
2019-08-15 17:11     ` Toke Høiland-Jørgensen
2019-08-16  6:12       ` Samudrala, Sridhar
2019-08-15 12:51 ` Björn Töpel
2019-08-15 16:46   ` Samudrala, Sridhar
2019-08-16 13:32     ` [Intel-wired-lan] " Björn Töpel
2019-08-16 22:08       ` Jonathan Lemon
2019-08-19  7:39         ` Björn Töpel
2019-08-15 19:28 ` Jakub Kicinski
2019-08-16  6:25   ` Samudrala, Sridhar [this message]

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