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From: Leonardo Bras Soares Passos <leobras@redhat.com>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: "Elena Ufimtseva" <elena.ufimtseva@oracle.com>,
	"John G Johnson" <john.g.johnson@oracle.com>,
	"Jagannathan Raman" <jag.raman@oracle.com>,
	qemu-block@nongnu.org, "Juan Quintela" <quintela@redhat.com>,
	"Daniel P. Berrangé" <berrange@redhat.com>,
	"Peter Xu" <peterx@redhat.com>,
	qemu-devel <qemu-devel@nongnu.org>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Marc-André Lureau" <marcandre.lureau@redhat.com>,
	"Fam Zheng" <fam@euphon.net>
Subject: Re: [PATCH v1 2/3] io: Add zerocopy and errqueue
Date: Wed, 8 Sep 2021 17:25:50 -0300	[thread overview]
Message-ID: <CAJ6HWG6L1LOec6yMY1oxFjbjhAv4LK6beS5FmU=g_s4h2+7ouA@mail.gmail.com> (raw)
In-Reply-To: <YTdHpx263WNe7nuZ@work-vm>

On Tue, Sep 7, 2021 at 8:06 AM Dr. David Alan Gilbert
<dgilbert@redhat.com> wrote:
> > Possibly, yes. This really need David G's input since he understands
> > the code in way more detail than me.
>
> Hmm I'm not entirely sure why we have the sync after each iteration;
> the case I can think of is if we're doing async sending, we could have
> two versions of the same page in flight (one from each iteration) -
> you'd want those to get there in the right order.
>
> Dave

Well, that's the thing: as we don't copy the buffer in MSG_ZEROCOPY,  we will in
fact have the same page in flight twice, instead of two versions,
given the buffer is
sent as it is during transmission.

For me it looks like there will be no change in the current algorithm,
but I am still
a beginner in migration code, and I am probably missing something.

Best regards,
Leo



  parent reply	other threads:[~2021-09-08 20:26 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-31 11:02 [PATCH v1 0/3] QIOChannel flags + multifd zerocopy Leonardo Bras
2021-08-31 11:02 ` [PATCH v1 1/3] io: Enable write flags for QIOChannel Leonardo Bras
2021-09-01 20:54   ` Eric Blake
2021-09-02  8:26     ` Leonardo Bras Soares Passos
2021-08-31 11:02 ` [PATCH v1 2/3] io: Add zerocopy and errqueue Leonardo Bras
2021-08-31 12:57   ` Daniel P. Berrangé
2021-08-31 20:27     ` Peter Xu
2021-09-01  8:50       ` Daniel P. Berrangé
2021-09-01 15:52         ` Peter Xu
2021-09-01 15:59           ` Daniel P. Berrangé
2021-09-02  7:07         ` Leonardo Bras Soares Passos
2021-09-02  6:59       ` Leonardo Bras Soares Passos
2021-09-07 16:44         ` Peter Xu
2021-09-08 20:13           ` Leonardo Bras Soares Passos
2021-09-08 21:04             ` Peter Xu
2021-09-02  6:38     ` Leonardo Bras Soares Passos
2021-09-02  8:47       ` Daniel P. Berrangé
2021-09-02  9:34         ` Leonardo Bras Soares Passos
2021-09-02  9:49           ` Daniel P. Berrangé
2021-09-02 10:19             ` Leonardo Bras Soares Passos
2021-09-02 10:28               ` Daniel P. Berrangé
2021-09-07 11:06                 ` Dr. David Alan Gilbert
2021-09-07 18:09                   ` Peter Xu
2021-09-08  8:30                     ` Dr. David Alan Gilbert
2021-09-08 15:24                       ` Peter Xu
2021-09-09  8:49                         ` Dr. David Alan Gilbert
2021-09-08 20:25                   ` Leonardo Bras Soares Passos [this message]
2021-09-08 21:09                     ` Peter Xu
2021-09-08 21:57                       ` Daniel P. Berrangé
2021-09-09  2:05                         ` Peter Xu
2021-09-09  4:58                           ` Leonardo Bras Soares Passos
2021-09-09 16:40                             ` Peter Xu
2021-08-31 11:02 ` [PATCH v1 3/3] migration: multifd: Enable zerocopy Leonardo Bras
2021-08-31 13:16   ` Daniel P. Berrangé
2021-08-31 20:29     ` Peter Xu
2021-09-01  8:53       ` Daniel P. Berrangé
2021-09-01 15:35         ` Peter Xu
2021-09-01 15:44           ` Daniel P. Berrangé
2021-09-01 16:01             ` Peter Xu
2021-09-02  7:57             ` Leonardo Bras Soares Passos
2021-09-07 11:13             ` Dr. David Alan Gilbert
2021-09-08 15:26               ` Daniel P. Berrangé
2021-09-02  7:23           ` Jason Wang
2021-09-02  8:08             ` Leonardo Bras Soares Passos
2021-09-02  7:27       ` Leonardo Bras Soares Passos
2021-09-02  7:22     ` Leonardo Bras Soares Passos
2021-09-02  8:20       ` Daniel P. Berrangé
2021-09-02  8:52         ` Leonardo Bras Soares Passos
2021-09-02  9:20           ` Daniel P. Berrangé
2021-09-02  9:49             ` Leonardo Bras Soares Passos
2021-09-02  9:59               ` Daniel P. Berrangé
2021-09-02 10:25                 ` Leonardo Bras Soares Passos
2021-09-07 11:17             ` Dr. David Alan Gilbert
2021-09-07 18:32       ` Peter Xu
2021-09-08  2:59         ` Jason Wang
2021-09-08  3:24           ` Peter Xu
2021-09-08  3:26             ` Jason Wang
2021-09-08  8:19           ` Dr. David Alan Gilbert
2021-09-08 15:19             ` Peter Xu
2021-09-09  1:10               ` Jason Wang
2021-08-31 21:24 ` [PATCH v1 0/3] QIOChannel flags + multifd zerocopy Peter Xu
2021-09-01 19:21   ` Leonardo Bras Soares Passos

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