From: David Laight <David.Laight@ACULAB.COM>
To: 'James Bottomley' <James.Bottomley@HansenPartnership.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Steven Sistare <steven.sistare@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>,
Anthony Yznaga <anthony.yznaga@oracle.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
"mhocko@kernel.org" <mhocko@kernel.org>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"mingo@redhat.com" <mingo@redhat.com>,
"bp@alien8.de" <bp@alien8.de>, "x86@kernel.org" <x86@kernel.org>,
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Subject: RE: [RFC PATCH 0/5] madvise MADV_DOEXEC
Date: Tue, 4 Aug 2020 08:44:42 +0000 [thread overview]
Message-ID: <9371b8272fd84280ae40b409b260bab3@AcuMS.aculab.com> (raw)
In-Reply-To: <1596469370.29091.13.camel@HansenPartnership.com>
From: James Bottomley
> Sent: 03 August 2020 16:43
>
> On Mon, 2020-08-03 at 10:28 -0500, Eric W. Biederman wrote:
> [...]
> > What is wrong with live migration between one qemu process and
> > another qemu process on the same machine not work for this use case?
> >
> > Just reusing live migration would seem to be the simplest path of
> > all, as the code is already implemented. Further if something goes
> > wrong with the live migration you can fallback to the existing
> > process. With exec there is no fallback if the new version does not
> > properly support the handoff protocol of the old version.
>
> Actually, could I ask this another way: the other patch set you sent to
> the KVM list was to snapshot the VM to a PKRAM capsule preserved across
> kexec using zero copy for extremely fast save/restore. The original
> idea was to use this as part of a CRIU based snapshot, kexec to new
> system, restore. However, why can't you do a local snapshot, restart
> qemu, restore using the PKRAM capsule to achieve exactly the same as
> MADV_DOEXEC does but using a system that's easy to reason about? It
> may be slightly slower, but I think we're still talking milliseconds.
I've had another idea (that is probably impossible...).
What about a 'reverse mmap' operation.
Something that creates an fd whose contents are a chunk of the
processes address space.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2020-08-04 8:44 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-27 17:11 [RFC PATCH 0/5] madvise MADV_DOEXEC Anthony Yznaga
2020-07-27 17:07 ` Eric W. Biederman
2020-07-27 18:00 ` Steven Sistare
2020-07-28 13:40 ` Christian Brauner
2020-07-27 17:11 ` [RFC PATCH 1/5] elf: reintroduce using MAP_FIXED_NOREPLACE for elf executable mappings Anthony Yznaga
2020-07-27 17:11 ` [RFC PATCH 2/5] mm: do not assume only the stack vma exists in setup_arg_pages() Anthony Yznaga
2020-07-27 17:11 ` [RFC PATCH 3/5] mm: introduce VM_EXEC_KEEP Anthony Yznaga
2020-07-28 13:38 ` Eric W. Biederman
2020-07-28 17:44 ` Anthony Yznaga
2020-07-29 13:52 ` Kirill A. Shutemov
2020-07-29 23:20 ` Anthony Yznaga
2020-07-27 17:11 ` [RFC PATCH 4/5] exec, elf: require opt-in for accepting preserved mem Anthony Yznaga
2020-07-27 17:11 ` [RFC PATCH 5/5] mm: introduce MADV_DOEXEC Anthony Yznaga
2020-07-28 13:22 ` Kirill Tkhai
2020-07-28 14:06 ` Steven Sistare
2020-07-28 11:34 ` [RFC PATCH 0/5] madvise MADV_DOEXEC Kirill Tkhai
2020-07-28 17:28 ` Anthony Yznaga
2020-07-28 14:23 ` Andy Lutomirski
2020-07-28 14:30 ` Steven Sistare
2020-07-30 15:22 ` Matthew Wilcox
2020-07-30 15:27 ` Christian Brauner
2020-07-30 15:34 ` Matthew Wilcox
2020-07-30 15:54 ` Christian Brauner
2020-07-31 9:12 ` Stefan Hajnoczi
2020-07-30 15:59 ` Steven Sistare
2020-07-30 17:12 ` Matthew Wilcox
2020-07-30 17:35 ` Steven Sistare
2020-07-30 17:49 ` Matthew Wilcox
2020-07-30 18:27 ` Steven Sistare
2020-07-30 21:58 ` Eric W. Biederman
2020-07-31 14:57 ` Steven Sistare
2020-07-31 15:27 ` Matthew Wilcox
2020-07-31 16:11 ` Steven Sistare
2020-07-31 16:56 ` Jason Gunthorpe
2020-07-31 17:15 ` Steven Sistare
2020-07-31 17:48 ` Jason Gunthorpe
2020-07-31 17:55 ` Steven Sistare
2020-08-03 8:32 ` David Laight
2020-07-31 17:23 ` Matthew Wilcox
2020-08-03 15:28 ` Eric W. Biederman
2020-08-03 15:42 ` James Bottomley
2020-08-03 20:03 ` Steven Sistare
2020-08-04 8:44 ` David Laight [this message]
2020-08-04 11:13 ` Matthew Wilcox
2020-08-03 19:29 ` Steven Sistare
2020-07-31 19:41 ` Steven Sistare
2021-07-08 9:52 ` Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
2021-07-08 12:48 ` Steven Sistare
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