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Tue, 27 Oct 2020 16:37:43 +0100 (CET) From: Markus Armbruster To: marcandre.lureau@redhat.com Subject: Re: [PATCH 0/3] console: make QMP screendump use coroutine References: <20201010204106.1368710-1-marcandre.lureau@redhat.com> Date: Tue, 27 Oct 2020 16:37:43 +0100 In-Reply-To: <20201010204106.1368710-1-marcandre.lureau@redhat.com> (marcandre lureau's message of "Sun, 11 Oct 2020 00:41:03 +0400") Message-ID: <87pn5365o8.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=63.128.21.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/27 01:06:07 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_H5=0.001, RCVD_IN_MSPIKE_WL=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: Kevin Wolf , Gerd Hoffmann , qemu-devel@nongnu.org, Stefan Hajnoczi , "Dr. David Alan Gilbert" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" marcandre.lureau@redhat.com writes: > From: Marc-Andr=C3=A9 Lureau > > Hi, > > Thanks to recent work by Kevin, it becomes possible to run HMP/QMP comman= ds i=3D > n a > coroutine. The screendump command is a good target, as it requires to re-= enter > the main-loop in ordre to flush the display, and write to file in a non-b= lock=3D > ing > way. > > Despite the flush, the dump may still have glitches. The graphic device m= ay > perform some operations during the write on the same framebuffer. Doing a= mem=3D > ory > copy could help, but it would also create a number of other issues. Keepi= ng t=3D > he > BQL would defeat a number of advantages of using a coroutine. Afaik, ther= e is=3D > no > mechanism to "freeze" the device either (and this could also have bad > consequences anyway). Good enough? This is v2 of Message-Id: <20200113144848.2168018-1-marcandre.lureau@redhat.com> https://lists.nongnu.org/archive/html/qemu-devel/2020-01/msg02313.html The title has become slightly misleading: v2 covers HMP, too, as the description says. A changelog would've helped me review. Next time :) [...]