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Date: Fri, 1 Mar 2024 10:10:43 -0800
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Subject: Re: [PATCH iwl-next,v2 1/2] selftests/bpf: xdp_hw_metadata reduce
 sleep interval
From: Stanislav Fomichev <sdf@google.com>
To: Song Yoong Siang <yoong.siang.song@intel.com>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>, Tony Nguyen <anthony.l.nguyen@intel.com>, 
	"David S . Miller" <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, 
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>, 
	Richard Cochran <richardcochran@gmail.com>, Alexei Starovoitov <ast@kernel.org>, 
	Daniel Borkmann <daniel@iogearbox.net>, Jesper Dangaard Brouer <hawk@kernel.org>, 
	John Fastabend <john.fastabend@gmail.com>, Vinicius Costa Gomes <vinicius.gomes@intel.com>, 
	Florian Bezdeka <florian.bezdeka@siemens.com>, Andrii Nakryiko <andrii@kernel.org>, 
	Eduard Zingerman <eddyz87@gmail.com>, Mykola Lysenko <mykolal@fb.com>, 
	Martin KaFai Lau <martin.lau@linux.dev>, Song Liu <song@kernel.org>, 
	Yonghong Song <yonghong.song@linux.dev>, KP Singh <kpsingh@kernel.org>, 
	Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>, Shuah Khan <shuah@kernel.org>, 
	intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, 
	linux-kernel@vger.kernel.org, bpf@vger.kernel.org, 
	linux-kselftest@vger.kernel.org, xdp-hints@xdp-project.net
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On 03/02, Song Yoong Siang wrote:
> In current ping-pong design, xdp_hw_metadata will wait until the packet
> transmition completely done, then only start to receive the next packet.
> 
> The current sleep interval is 10ms, which is unnecessary large. Typically,
> a NIC does not need such a long time to transmit a packet. Furthermore,
> during this 10ms sleep time, the app is unable to receive incoming packets.
> 
> Therefore, this commit reduce sleep interval to 10us, so that
> xdp_hw_metadata able to support periodic packets with shorter interval.
> 10us * 500 = 5ms should be enough for packet transmission and status
> retrival.
> 
> Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com>

Acked-by: Stanislav Fomichev <sdf@google.com>