[libvirt] [Xen-devel] [PATCH 00/12] libxl: fork: SIGCHLD flexibility

Daniel P. Berrange berrange at redhat.com
Thu Jan 30 12:18:05 UTC 2014

On Mon, Jan 27, 2014 at 06:39:36PM -0700, Jim Fehlig wrote:
> [Adding libvirt list...]
> Ian Jackson wrote:
> > Jim Fehlig writes ("Re: [Xen-devel] [PATCH 00/12] libxl: fork: SIGCHLD flexibility"):

BTW, I meant to ask before - what is the SIGCHLD reference about in the
subject line ?

libvirt drivers that live inside libvirtd should never use or rely on
the SIGCHLD signal at all. All VM processes started by libvirtd ought
to be fully daemonized so that their parent is pid 1 / init. This ensures
that the libvirtd daemon can be restarted without all the VMs getting
reaped. Once the VMs are reparented to init, then libvirt or library
code it uses has no way of ever receiving SIGCHLD.

I'm unclear if the libvirt libxl driver is currently daemonizing the
processes associated with VMs it starts, but if not, it really should

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