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From: Stefan Hajnoczi <stefanha@gmail.com>
To: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>,
	qemu-devel <qemu-devel@nongnu.org>, John Snow <jsnow@redhat.com>,
	"Denis V. Lunev" <den@openvz.org>, Rik van Riel <riel@redhat.com>
Subject: Re: [Qemu-devel] Async savevm using userfaultfd(2)
Date: Fri, 14 Oct 2016 17:45:55 +0100	[thread overview]
Message-ID: <20161014164555.GL3482@stefanha-x1.localdomain> (raw)
In-Reply-To: <20161013142719.GK5613@redhat.com>

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On Thu, Oct 13, 2016 at 04:27:19PM +0200, Andrea Arcangeli wrote:
> I would suggest not to implement mprotect+sigsegv because maintaining
> both APIs would be messy but mostly because mprotect cannot really
> work for all cases and it would risk to fail at any time with
> -ENOMEM. postcopy live migration had similar issues and this is why it
> wasn't possible to achieve it reliably without userfaultfd.

Yes, thanks for explaining the issues.  I agree that the mprotect
approach isn't worthwhile.  We need to use userfaultfd.

Stefan

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      reply	other threads:[~2016-10-14 16:46 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-12 14:04 [Qemu-devel] Async savevm using userfaultfd(2) Stefan Hajnoczi
2016-10-12 14:18 ` Eric Blake
2016-10-12 14:21 ` Dr. David Alan Gilbert
2016-10-13  1:11   ` Hailiang Zhang
2016-10-12 15:16 ` Denis V. Lunev
2016-10-13  5:15 ` Stefan Hajnoczi
2016-10-13  8:30   ` Dr. David Alan Gilbert
2016-10-13 14:27     ` Andrea Arcangeli
2016-10-14 16:45       ` Stefan Hajnoczi [this message]

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