From: "Daniel P. Berrangé" <berrange@redhat.com>
To: Markus Armbruster <armbru@redhat.com>
Cc: Peter Xu <peterx@redhat.com>,
qemu-devel@nongnu.org, Prasad Pandit <ppandit@redhat.com>,
Julia Suvorova <jusual@redhat.com>,
Fabiano Rosas <farosas@suse.de>,
Juraj Marcin <jmarcin@redhat.com>,
"Dr . David Alan Gilbert" <dave@treblig.org>
Subject: Re: [PATCH 0/7] migration: query-migrationthreads enhancements and cleanups
Date: Tue, 1 Oct 2024 15:25:14 +0100 [thread overview]
Message-ID: <ZvwGSgDnW8KfgFEh@redhat.com> (raw)
In-Reply-To: <87o744e5pa.fsf@pond.sub.org>
On Tue, Oct 01, 2024 at 07:46:09AM +0200, Markus Armbruster wrote:
> Command query-migrationthreads went in without a QAPI ACK. Issues
> review should have caught:
>
> * Flawed documentation. Fixed in commit e6c60bf02d1.
>
> * It should have been spelled query-migration-threads. Not worth fixing
> now, I guess.
>
> * What are the use cases? The commit message doesn't tell! If it's
> just for debugging, the command should be marked unstable.
It is hard to use too.
Lets say a mgmt app wants to restrict migration threads to some
certain pCPUs. It can't call query-migrationthreads beforehand
as the threads don't exist until migration is started. If it
calls after migration is started, then there's a window where
threads are running on arbitrary pCPUs that QEMU has access
to. There's no synchronization point where threads have been
created & can be queried, but are not yet sending data (and
thus burning CPU time)
With regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
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next prev parent reply other threads:[~2024-10-01 14:29 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-30 19:58 [PATCH 0/7] migration: query-migrationthreads enhancements and cleanups Peter Xu
2024-09-30 19:58 ` [PATCH 1/7] migration: Unify names of migration src main thread Peter Xu
2024-09-30 19:58 ` [PATCH 2/7] migration: Put thread names together with macros Peter Xu
2024-09-30 19:58 ` [PATCH 3/7] migration: Remove thread_id in migration_threads_add() Peter Xu
2024-09-30 19:58 ` [PATCH 4/7] migration: Simplify migration-threads API Peter Xu
2024-09-30 19:58 ` [PATCH 5/7] migration: Add all threads with QMP query-migrationthreads Peter Xu
2024-09-30 19:58 ` [PATCH 6/7] migration: Remove MigrationThread and threadinfo.h Peter Xu
2024-09-30 19:58 ` [PATCH 7/7] hmp: Add "info migrationthreads" Peter Xu
2024-09-30 23:43 ` Dr. David Alan Gilbert
2024-10-01 5:46 ` [PATCH 0/7] migration: query-migrationthreads enhancements and cleanups Markus Armbruster
2024-10-01 14:25 ` Daniel P. Berrangé [this message]
2024-10-01 15:06 ` Peter Xu
2024-10-02 5:58 ` Markus Armbruster
2024-10-10 19:46 ` Peter Xu
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