From: Juergen Gross <jgross@suse.com>
To: Julien Grall <julien@xen.org>, xen-devel@lists.xenproject.org
Cc: raphning@amazon.co.uk, doebel@amazon.de,
Julien Grall <jgrall@amazon.com>,
Ian Jackson <iwj@xenproject.org>, Wei Liu <wl@xen.org>
Subject: Re: [PATCH 10/10] tools/xenstored: Delay new transaction while Live-Update is pending
Date: Thu, 24 Jun 2021 11:23:59 +0200 [thread overview]
Message-ID: <f2a5a643-17fb-4cb3-fb54-2c80ec45e43e@suse.com> (raw)
In-Reply-To: <20210616144324.31652-11-julien@xen.org>
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On 16.06.21 16:43, Julien Grall wrote:
> From: Julien Grall <jgrall@amazon.com>
>
> At the moment, Live-Update will, by default, not proceed if there are
> in-flight transactions. It is possible force it by passing -F but this
> will break any connection with in-flight transactions.
>
> There are PV drivers out that may never terminate some transaction. On
> host running such guest, we would need to use -F. Unfortunately, this
> also risks to break well-behaving guests (and even dom0) because
> Live-Update will happen as soon as the timeout is hit.
>
> Ideally, we would want to preserve transactions but this requires
> some work and a lot of testing to be able to use it in production.
>
> As a stop gap, we want to limit the damage of -F. This patch will delay
> any transactions that are started after Live-Update has been requested.
>
> If the request cannot be delayed, the connection will be stalled to
> avoid loosing requests.
>
> If the connection has already a pending transaction before Live-Update,
> then new transaction will not be delayed. This is to avoid the connection
> to stall.
>
> With this stop gap in place, domains with long running transactions will
> still break when using -F, but other domains which starts a transaction
> in the middle of Live-Update will continue to work.
>
> Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Juergen
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next prev parent reply other threads:[~2021-06-24 9:24 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-16 14:43 [PATCH 00/10] tools/xenstored: Bug fixes + Improve Live-Update Julien Grall
2021-06-16 14:43 ` [PATCH 01/10] MAINTAINERS: Add myself as reviewers for tools/xenstore Julien Grall
2021-06-16 15:15 ` Juergen Gross
2021-06-16 14:43 ` [PATCH 02/10] tools/xenstored: Introduce lu_get_connection() and use it Julien Grall
2021-06-21 8:21 ` Luca Fancellu
2021-06-24 7:21 ` Juergen Gross
2021-06-16 14:43 ` [PATCH 03/10] tools/xenstore: Don't assume conn->in points to the LU request Julien Grall
2021-06-21 8:55 ` Luca Fancellu
2021-06-24 8:06 ` Julien Grall
2021-06-24 7:32 ` Juergen Gross
2021-06-24 7:34 ` Juergen Gross
2021-06-24 7:56 ` Luca Fancellu
2021-06-24 8:05 ` Juergen Gross
2021-06-16 14:43 ` [PATCH 04/10] tools/xenstored: Limit the number of requests a connection can delay Julien Grall
2021-06-21 9:02 ` Luca Fancellu
2021-06-24 7:35 ` Juergen Gross
2021-06-16 14:43 ` [PATCH 05/10] tools/xenstored: xenstored_core.h should include fcntl.h Julien Grall
2021-06-21 9:03 ` Luca Fancellu
2021-06-24 7:36 ` Juergen Gross
2021-06-16 14:43 ` [PATCH 06/10] tools/xenstored: Introduce a wrapper for conn->funcs->can_{read, write} Julien Grall
2021-06-21 9:10 ` Luca Fancellu
2021-06-24 7:39 ` Juergen Gross
2021-06-16 14:43 ` [PATCH 07/10] tools/xenstored: delay_request: don't assume conn->in == in Julien Grall
2021-06-21 9:12 ` Luca Fancellu
2021-06-24 7:44 ` Juergen Gross
2021-06-24 7:58 ` Julien Grall
2021-06-16 14:43 ` [PATCH 08/10] tools/xenstored: Extend restore code to handle multiple input buffer Julien Grall
2021-06-21 9:21 ` Luca Fancellu
2021-06-24 8:30 ` Juergen Gross
2021-06-24 8:42 ` Julien Grall
2021-06-24 9:20 ` Juergen Gross
2021-06-16 14:43 ` [PATCH 09/10] tools/xenstored: Dump delayed requests Julien Grall
2021-06-21 9:27 ` Luca Fancellu
2021-06-24 8:41 ` Juergen Gross
2021-06-24 10:28 ` Julien Grall
2021-06-24 10:45 ` Juergen Gross
2021-06-24 10:46 ` Julien Grall
2021-06-24 11:02 ` Juergen Gross
2021-06-24 11:17 ` Julien Grall
2021-06-16 14:43 ` [PATCH 10/10] tools/xenstored: Delay new transaction while Live-Update is pending Julien Grall
2021-06-21 9:30 ` Luca Fancellu
2021-06-24 9:23 ` Juergen Gross [this message]
2021-06-24 10:43 ` [PATCH 00/10] tools/xenstored: Bug fixes + Improve Live-Update Julien Grall
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