From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D5EF5D1CDC7 for ; Tue, 22 Oct 2024 09:22:17 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t3B55-0006RF-RR; Tue, 22 Oct 2024 05:21:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1t3B54-0006QZ-0e for qemu-devel@nongnu.org; Tue, 22 Oct 2024 05:21:34 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1t3B51-0006sO-CC for qemu-devel@nongnu.org; Tue, 22 Oct 2024 05:21:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1729588889; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=b5qVkVFEWz5v7AcT89LrvzcUTgpVk05nxhe4LucWPsk=; b=DtWHq0W2fpypYBlsTFeTx8VbTBelIOq5ryUvVwxVbQe0v7a/1tN1JAGQWmA/7FOqVLZpCn ct/lx5oSD5VCpHu101T57J2nQ2pjLyNy6G0Ri3xR/z6w030FM7uTJvy/mpZuF9kLDY8nRy iHM/68CAVr3TxlPmwPRm0CqNMYQW4bA= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-623-B3Fs-k1JPO6wnaTNnA-LWw-1; Tue, 22 Oct 2024 05:21:27 -0400 X-MC-Unique: B3Fs-k1JPO6wnaTNnA-LWw-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B3FF4195608B; Tue, 22 Oct 2024 09:21:26 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.59]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 63B9119560AE; Tue, 22 Oct 2024 09:21:22 +0000 (UTC) Date: Tue, 22 Oct 2024 10:21:18 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Markus Armbruster Cc: Peter Xu , qemu-devel@nongnu.org, "Dr . David Alan Gilbert" , Juraj Marcin , Prasad Pandit , Julia Suvorova , Fabiano Rosas Subject: Re: [PATCH] migration: Deprecate query-migrationthreads command Message-ID: References: <20241021215220.982325-1-peterx@redhat.com> <87froo34xy.fsf@pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <87froo34xy.fsf@pond.sub.org> User-Agent: Mutt/2.2.12 (2023-09-09) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.421, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-1.699, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, Oct 22, 2024 at 10:41:29AM +0200, Markus Armbruster wrote: > Peter Xu writes: > > > Per previous discussion [1,2], this patch deprecates query-migrationthreads > > command. > > > > To summarize, the major reason of the deprecation is due to no sensible way > > to consume the API properly: > > > > (1) The reported list of threads are incomplete (ignoring destination > > threads and non-multifd threads). > > > > (2) For CPU pinning, there's no way to properly pin the threads with > > the API if the threads will start running right away after migration > > threads can be queried, so the threads will always run on the default > > cores for a short window. > > > > (3) For VM debugging, one can use "-name $VM,debug-threads=on" instead, > > which will provide proper names for all migration threads. > > > > [1] https://lore.kernel.org/r/20240930195837.825728-1-peterx@redhat.com > > [2] https://lore.kernel.org/r/20241011153417.516715-1-peterx@redhat.com > > > > Signed-off-by: Peter Xu > > --- > > docs/about/deprecated.rst | 8 ++++++++ > > qapi/migration.json | 6 +++++- > > migration/threadinfo.c | 4 ++++ > > 3 files changed, 17 insertions(+), 1 deletion(-) > > > > diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst > > index ce38a3d0cf..ffb147e896 100644 > > --- a/docs/about/deprecated.rst > > +++ b/docs/about/deprecated.rst > > @@ -147,6 +147,14 @@ options are removed in favor of using explicit ``blockdev-create`` and > > ``blockdev-add`` calls. See :doc:`/interop/live-block-operations` for > > details. > > > > +``query-migrationthreads`` (since 9.2) > > +''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' > > + > > +To be removed with no replacement, as it reports only a limited set of > > +threads (for example, it only reports source side of multifd threads, > > +without reporting any destination threads, or non-multifd source threads). > > +For debugging purpose, please use ``-name $VM,debug-threads=on`` instead. > > This covers commit message items (1) and (3), but not (2). Observation, > not objection. > > > + > > Incorrectly typed ``device_add`` arguments (since 6.2) > > '''''''''''''''''''''''''''''''''''''''''''''''''''''' > > > > diff --git a/qapi/migration.json b/qapi/migration.json > > index 3af6aa1740..a71a9f0cd3 100644 > > --- a/qapi/migration.json > > +++ b/qapi/migration.json > > @@ -2284,12 +2284,16 @@ > > # > > # Returns information of migration threads > > # > > +# Features: > > Blank line, please. > > > +# @deprecated: This command is deprecated with no replacement yet. > > +# > > # Returns: @MigrationThreadInfo > > # > > # Since: 7.2 > > ## > > { 'command': 'query-migrationthreads', > > - 'returns': ['MigrationThreadInfo'] } > > + 'returns': ['MigrationThreadInfo'], > > + 'features': ['deprecated'] } > > > > ## > > # @snapshot-save: > > diff --git a/migration/threadinfo.c b/migration/threadinfo.c > > index 262990dd75..2867413420 100644 > > --- a/migration/threadinfo.c > > +++ b/migration/threadinfo.c > > @@ -13,6 +13,7 @@ > > #include "qemu/osdep.h" > > #include "qemu/queue.h" > > #include "qemu/lockable.h" > > +#include "qemu/error-report.h" > > #include "threadinfo.h" > > > > QemuMutex migration_threads_lock; > > @@ -52,6 +53,9 @@ MigrationThreadInfoList *qmp_query_migrationthreads(Error **errp) > > MigrationThread *thread = NULL; > > > > QEMU_LOCK_GUARD(&migration_threads_lock); > > + > > + warn_report("Command 'query-migrationthreads' is deprecated"); > > We don't normally do this for QMP commands. > > Management applications can use -compat deprecated-input=reject to check > they're not sending deprecated commands or arguments. > > Suggest to drop. They could, but in practice I don't believe anything is doing this, so the warning message is a practical way to alert people to the usage. > > > + > > QLIST_FOREACH(thread, &migration_threads, node) { > > MigrationThreadInfo *info = g_new0(MigrationThreadInfo, 1); > > info->name = g_strdup(thread->name); > > Acked-by: Markus Armbruster > With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|