* [PATCH] migration: Don't try and recover return path in non-postcopy
@ 2019-10-07 10:35 Dr. David Alan Gilbert (git)
2019-10-07 10:38 ` Greg Kurz
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Dr. David Alan Gilbert (git) @ 2019-10-07 10:35 UTC (permalink / raw)
To: qemu-devel, peterx, quintela, groug
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
In normal precopy we can't do reconnection recovery - but we also
don't need to, since you can just rerun migration.
At the moment if the 'return-path' capability is on, we use
the return path in precopy to give a postiive 'OK' to the end
of migration; however if migration fails then we fall into
the postcopy recovery path and hang. This fixes it by only
running the return path in the postcopy case.
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
migration/migration.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/migration/migration.c b/migration/migration.c
index 5f7e4d15e9..d5d9b31bb7 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -2481,7 +2481,7 @@ retry:
out:
res = qemu_file_get_error(rp);
if (res) {
- if (res == -EIO) {
+ if (res == -EIO && migration_in_postcopy()) {
/*
* Maybe there is something we can do: it looks like a
* network down issue, and we pause for a recovery.
--
2.21.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] migration: Don't try and recover return path in non-postcopy
2019-10-07 10:35 [PATCH] migration: Don't try and recover return path in non-postcopy Dr. David Alan Gilbert (git)
@ 2019-10-07 10:38 ` Greg Kurz
2019-10-08 14:14 ` Peter Xu
2019-10-11 13:26 ` Dr. David Alan Gilbert
2 siblings, 0 replies; 4+ messages in thread
From: Greg Kurz @ 2019-10-07 10:38 UTC (permalink / raw)
To: Dr. David Alan Gilbert (git); +Cc: qemu-devel, peterx, quintela
On Mon, 7 Oct 2019 11:35:07 +0100
"Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> In normal precopy we can't do reconnection recovery - but we also
> don't need to, since you can just rerun migration.
> At the moment if the 'return-path' capability is on, we use
> the return path in precopy to give a postiive 'OK' to the end
s/postiive/positive
> of migration; however if migration fails then we fall into
> the postcopy recovery path and hang. This fixes it by only
> running the return path in the postcopy case.
>
> Reported-by: Greg Kurz <groug@kaod.org>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
Thanks !
Tested-by: Greg Kurz <groug@kaod.org>
> migration/migration.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/migration/migration.c b/migration/migration.c
> index 5f7e4d15e9..d5d9b31bb7 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -2481,7 +2481,7 @@ retry:
> out:
> res = qemu_file_get_error(rp);
> if (res) {
> - if (res == -EIO) {
> + if (res == -EIO && migration_in_postcopy()) {
> /*
> * Maybe there is something we can do: it looks like a
> * network down issue, and we pause for a recovery.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] migration: Don't try and recover return path in non-postcopy
2019-10-07 10:35 [PATCH] migration: Don't try and recover return path in non-postcopy Dr. David Alan Gilbert (git)
2019-10-07 10:38 ` Greg Kurz
@ 2019-10-08 14:14 ` Peter Xu
2019-10-11 13:26 ` Dr. David Alan Gilbert
2 siblings, 0 replies; 4+ messages in thread
From: Peter Xu @ 2019-10-08 14:14 UTC (permalink / raw)
To: Dr. David Alan Gilbert (git); +Cc: groug, qemu-devel, quintela
On Mon, Oct 07, 2019 at 11:35:07AM +0100, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> In normal precopy we can't do reconnection recovery - but we also
> don't need to, since you can just rerun migration.
> At the moment if the 'return-path' capability is on, we use
> the return path in precopy to give a postiive 'OK' to the end
> of migration; however if migration fails then we fall into
> the postcopy recovery path and hang. This fixes it by only
> running the return path in the postcopy case.
>
> Reported-by: Greg Kurz <groug@kaod.org>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
> migration/migration.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/migration/migration.c b/migration/migration.c
> index 5f7e4d15e9..d5d9b31bb7 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -2481,7 +2481,7 @@ retry:
> out:
> res = qemu_file_get_error(rp);
> if (res) {
> - if (res == -EIO) {
> + if (res == -EIO && migration_in_postcopy()) {
Makes sense! I saw that in qemu_loadvm_state_main() we're using
(postcopy_state_get() == POSTCOPY_INCOMING_RUNNING) to check. That
also makes sense because I think we can't really do the recover if the
migration stream failed at status like POSTCOPY_INCOMING_DISCARD even
if it switched to POSTCOPY_ACTIVE... However that should really be a
very corner case even if it's true, and afaict it's nowhere worse...
Reviewed-by: Peter Xu <peterx@redhat.com>
--
Peter Xu
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] migration: Don't try and recover return path in non-postcopy
2019-10-07 10:35 [PATCH] migration: Don't try and recover return path in non-postcopy Dr. David Alan Gilbert (git)
2019-10-07 10:38 ` Greg Kurz
2019-10-08 14:14 ` Peter Xu
@ 2019-10-11 13:26 ` Dr. David Alan Gilbert
2 siblings, 0 replies; 4+ messages in thread
From: Dr. David Alan Gilbert @ 2019-10-11 13:26 UTC (permalink / raw)
To: qemu-devel, peterx, quintela, groug
* Dr. David Alan Gilbert (git) (dgilbert@redhat.com) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> In normal precopy we can't do reconnection recovery - but we also
> don't need to, since you can just rerun migration.
> At the moment if the 'return-path' capability is on, we use
> the return path in precopy to give a postiive 'OK' to the end
> of migration; however if migration fails then we fall into
> the postcopy recovery path and hang. This fixes it by only
> running the return path in the postcopy case.
>
> Reported-by: Greg Kurz <groug@kaod.org>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Queued
> ---
> migration/migration.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/migration/migration.c b/migration/migration.c
> index 5f7e4d15e9..d5d9b31bb7 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -2481,7 +2481,7 @@ retry:
> out:
> res = qemu_file_get_error(rp);
> if (res) {
> - if (res == -EIO) {
> + if (res == -EIO && migration_in_postcopy()) {
> /*
> * Maybe there is something we can do: it looks like a
> * network down issue, and we pause for a recovery.
> --
> 2.21.0
>
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-10-11 13:27 UTC | newest]
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2019-10-07 10:35 [PATCH] migration: Don't try and recover return path in non-postcopy Dr. David Alan Gilbert (git)
2019-10-07 10:38 ` Greg Kurz
2019-10-08 14:14 ` Peter Xu
2019-10-11 13:26 ` Dr. David Alan Gilbert
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