From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To: Wei Yang <richardw.yang@linux.intel.com>
Cc: qemu-devel@nongnu.org, quintela@redhat.com
Subject: Re: [PATCH 2/3] migration/postcopy: postpone setting PostcopyState to END
Date: Tue, 8 Oct 2019 20:06:04 +0100 [thread overview]
Message-ID: <20191008190604.GM3441@work-vm> (raw)
In-Reply-To: <20191006000249.29926-3-richardw.yang@linux.intel.com>
* Wei Yang (richardw.yang@linux.intel.com) wrote:
> There are two places to call function postcopy_ram_incoming_cleanup()
>
> postcopy_ram_listen_thread on migration success
> loadvm_postcopy_handle_listen one setup failure
>
> On success, the vm will never accept another migration. On failure,
> PostcopyState is transited from LISTENING to END and would be checked in
> qemu_loadvm_state_main(). If PostcopyState is RUNNING, migration would
> be paused and retried.
>
> Currently PostcopyState is set to END in function
> postcopy_ram_incoming_cleanup(). With above analysis, we can take this
> step out and postpone this till the end of listen thread to indicate the
> listen thread is done.
>
> This is a preparation patch for later cleanup.
>
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Yes, I think that's OK - I couldn't see anywhere that's currently
checking the state in between.
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
> migration/postcopy-ram.c | 2 --
> migration/savevm.c | 2 ++
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
> index a394c7c3a6..5da6de8c8b 100644
> --- a/migration/postcopy-ram.c
> +++ b/migration/postcopy-ram.c
> @@ -577,8 +577,6 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
> }
> }
>
> - postcopy_state_set(POSTCOPY_INCOMING_END, NULL);
> -
> if (mis->postcopy_tmp_page) {
> munmap(mis->postcopy_tmp_page, mis->largest_page_size);
> mis->postcopy_tmp_page = NULL;
> diff --git a/migration/savevm.c b/migration/savevm.c
> index eaa4cf58ef..dcad8897a3 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1837,6 +1837,8 @@ static void *postcopy_ram_listen_thread(void *opaque)
>
> rcu_unregister_thread();
> mis->have_listen_thread = false;
> + postcopy_state_set(POSTCOPY_INCOMING_END, NULL);
> +
> return NULL;
> }
>
> --
> 2.17.1
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
next prev parent reply other threads:[~2019-10-08 19:07 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-06 0:02 [PATCH 0/3] migration/postcopy: replace have_listen_thread check with PostcopyState check Wei Yang
2019-10-06 0:02 ` [PATCH 1/3] migration/postcopy: mis->have_listen_thread check will never be touched Wei Yang
2019-10-08 18:47 ` Dr. David Alan Gilbert
2019-10-06 0:02 ` [PATCH 2/3] migration/postcopy: postpone setting PostcopyState to END Wei Yang
2019-10-08 19:06 ` Dr. David Alan Gilbert [this message]
2019-10-06 0:02 ` [PATCH 3/3] migration/postcopy: replace have_listen_thread check with PostcopyState check Wei Yang
2019-10-08 19:15 ` Dr. David Alan Gilbert
2019-10-09 1:37 ` Wei Yang
2019-10-09 10:17 ` Dr. David Alan Gilbert
2019-10-10 1:21 ` Wei Yang
2019-10-11 13:58 ` [PATCH 0/3] " Dr. David Alan Gilbert
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