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Thu, 02 Sep 2021 00:27:03 -0700 (PDT) X-Google-Smtp-Source: ABdhPJx6eh8Pgn/5MimyjfksiNrDG0fkNAHMcck/xShRHyrf92n9TE/xU5+JyBk1ipDqJPx533CvaE0tFT8mDcLx30Q= X-Received: by 2002:a05:651c:10a2:: with SMTP id k2mr1378199ljn.262.1630567623169; Thu, 02 Sep 2021 00:27:03 -0700 (PDT) MIME-Version: 1.0 References: <20210831110238.299458-1-leobras@redhat.com> <20210831110238.299458-4-leobras@redhat.com> In-Reply-To: From: Leonardo Bras Soares Passos Date: Thu, 2 Sep 2021 04:27:14 -0300 Message-ID: Subject: Re: [PATCH v1 3/3] migration: multifd: Enable zerocopy To: Peter Xu Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=lsoaresp@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=216.205.24.124; envelope-from=lsoaresp@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.392, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Elena Ufimtseva , John G Johnson , Jagannathan Raman , qemu-block@nongnu.org, Juan Quintela , qemu-devel , =?UTF-8?Q?Daniel_P=2E_Berrang=C3=A9?= , "Dr. David Alan Gilbert" , Paolo Bonzini , =?UTF-8?B?TWFyYy1BbmRyw6kgTHVyZWF1?= , Fam Zheng Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Hello Peter, thank you for this feedback! On Tue, Aug 31, 2021 at 5:29 PM Peter Xu wrote: > Yes it would be great to be a migration capability in parallel to multifd. At > initial phase if it's easy to be implemented on multi-fd only, we can add a > dependency between the caps. In the future we can remove that dependency when > the code is ready to go without multifd. Thanks, I thought the idea was to use MSG_ZEROCOPY whenever possible, and otherwise fall back to the default copying mechanism. On replies to 2/3 I mentioned a new method to QIOChannel interface, that would fall back to copying, and that may be a way to not have to use a capability. Best regards, Leonardo