..and why we got to this situation. (per Anthony's request, and if you'll excuse the puny attempt to write biblically, a new beginning)
In the begining there was screendump. It was a synchronous monitor command. Libvirt said: I want a screendump. And qemu waited for the vga device to produce it. When the vga device said it was done, libvirt was done. Then there came qxl. Qxl used a spice library to render the contents. It would say to libvirt: wait, while I read on this thread, which will tell me I am done. And so it was possible to hang the libvirt process: tl;dr if spice client hangs libvirt screenshot hangs and qemu's vcpus starve. http://lists.gnu.org/archive/html/qemu-devel/2012-03/msg00864.html Then a new patchset landed, which stopped the read, by waiting for a callback from the spice server. It is here: http://patchwork.ozlabs.org/patch/142985/ commited as 81fb6f1504fb9ef71f2382f44af34756668296e8 But now screendump for qxl is broken: It produces a file that is old, because it calls ppm_save before spice server is done rendering. Now we come to now. My understanding from the previous thread is: * monitor async is not good because Luiz said so. (yes, I know I'm putting my head in the sand here) If the above is enough to convince you of $SUBJECT, then the screendump-async patchset is still waiting review :) http://patchwork.ozlabs.org/patch/144704/ http://patchwork.ozlabs.org/patch/144705/ http://patchwork.ozlabs.org/patch/144706/ Alon
