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Szmigiero" , Daniel P =?utf-8?B?LiBCZXJyYW5nw6k=?= , Joao Martins , Alex Williamson , Yishai Hadas , Fabiano Rosas , Pranav Tyagi , Zhiyi Guo , Markus Armbruster , Avihai Horon , =?utf-8?Q?C=C3=A9dric?= Le Goater Subject: Re: [PATCH RFC 11/12] migration: Calculate expected downtime on demand Message-ID: References: <20260319231302.123135-1-peterx@redhat.com> <20260319231302.123135-12-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Received-SPF: pass client-ip=170.10.133.124; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.54, 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=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-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: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Fri, Mar 27, 2026 at 06:17:03PM +0100, Juraj Marcin wrote: > > +/* Return expected downtime (unit: milliseconds) */ > > +int64_t migration_downtime_calc_expected(MigrationState *s) > > +{ > > + if (mig_stats.dirty_sync_count <= 1) { > > + return migrate_downtime_limit(); > > + } > > + > > + return 1.0 * mig_stats.dirty_bytes_last_sync / > > If the intention of '1.0 *' was to get double out of dirty_bytes_last_sync, I think > an explicit cast would be better. Let me drop the "1.0 *"; it's not needed when the divisor is double. Thanks, > > > + migration_get_switchover_bw(s) * 1000; > > +} -- Peter Xu