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From: David Laight <David.Laight@ACULAB.COM>
To: 'Bui Quang Minh' <minhquangbui99@gmail.com>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Cc: "davem@davemloft.net" <davem@davemloft.net>,
	"kuba@kernel.org" <kuba@kernel.org>,
	"yoshfuji@linux-ipv6.org" <yoshfuji@linux-ipv6.org>,
	"dsahern@kernel.org" <dsahern@kernel.org>,
	"willemb@google.com" <willemb@google.com>,
	"pabeni@redhat.com" <pabeni@redhat.com>,
	"avagin@gmail.com" <avagin@gmail.com>,
	"alexander@mihalicyn.com" <alexander@mihalicyn.com>,
	"lesedorucalin01@gmail.com" <lesedorucalin01@gmail.com>
Subject: RE: [PATCH v2 1/2] udp: UDP socket send queue repair
Date: Fri, 13 Aug 2021 13:00:12 +0000	[thread overview]
Message-ID: <29dc7ac9781344f1a57e16c14900a7da@AcuMS.aculab.com> (raw)
In-Reply-To: <3f861c1d-bd33-f074-8ef3-eede9bff73c1@gmail.com>

From: Bui Quang Minh
> Sent: 13 August 2021 12:08
...
> The reason we want to dump the packet in send queue is to make to state of the
> application consistent. The scenario is that when an application sends UDP
> packets via UDP_CORK socket or with MSG_MORE, CRIU comes and checkpoints the
> application. If we drop the data in send queue, when application restores, it
> sends some more data then turns off the cork and actually sends a packet. The
> receiving side may get that packet but it's unusual that the first part of that
> packet is missing because we drop it. So we try to solve this problem with some
> help from the Linux kernel.

Patient: It hurts if I do xxx.
Doctor: Don't do xxx then.

It has to be more efficient to buffer partial UDP packets
in userspace and only send when all the packet is available.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

  reply	other threads:[~2021-08-13 13:00 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-11 15:45 Bui Quang Minh
2021-08-11 16:14 ` Eric Dumazet
2021-08-12 13:46   ` Bui Quang Minh
2021-08-12 15:51     ` Eric Dumazet
2021-08-13 11:08       ` Bui Quang Minh
2021-08-13 13:00         ` David Laight [this message]
2021-08-17 16:22           ` avagin
2021-08-16 14:35         ` Willem de Bruijn
2021-08-16 14:38 ` Willem de Bruijn

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