On Fri, Sep 04, 2015 at 03:31:24PM +1000, David Gibson wrote: > On Thu, Aug 06, 2015 at 10:57:07AM +0530, Bharata B Rao wrote: > > CPUState *cpu gets added to the cpus list during cpu_exec_init(). It > > should be removed from cpu_exec_exit(). > > > > cpu_exec_init() is called from generic CPU::instance_finalize and some > > archs like PowerPC call it from CPU unrealizefn. So ensure that we > > dequeue the cpu only once. > > > > Instead of introducing a new field CPUState.queued, I could have used > > CPUState.cpu_index to check if the cpu is already dequeued from the list. > > Since that doesn't work for CONFIG_USER_ONLY, I had to add a new field. > > > > Signed-off-by: Bharata B Rao <bhar...@linux.vnet.ibm.com> > > This seems reasonable to me, but I'm wondering how x86 cpu hotplug / > unplug is working without it.
x86 hotplug/unplug code currently resides in Zhu's git tree (git://github.com/zhugh/qemu). They are removing the CPU from the list explicitly in x86 CPU's instance_finalize routine. Since we add CPU to the list in cpu_exec_init(), I thought it makes sense to remove it in cpu_exec_exit(). May be it makes sense to separately purse this patch and the next one so that other archs are also taken into account correctly. Regards, Bharata.
