From: "Daniel P. Berrange" <berrange@redhat.com>
To: Jim Fehlig <jfehlig@suse.com>
Cc: LibVir <libvir-list@redhat.com>,
xen-devel@lists.xensource.com,
Ian Jackson <Ian.Jackson@eu.citrix.com>,
Ian Campbell <ian.campbell@citrix.com>
Subject: Re: [libvirt] [Xen-devel] [PATCH 00/12] libxl: fork: SIGCHLD flexibility
Date: Thu, 30 Jan 2014 16:17:30 +0000 [thread overview]
Message-ID: <20140130161730.GN3139@redhat.com> (raw)
In-Reply-To: <52EA7A49.2040105@suse.com>
On Thu, Jan 30, 2014 at 09:14:01AM -0700, Jim Fehlig wrote:
> Daniel P. Berrange wrote:
> > 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 ?
> >
>
> This is related to child processes started by libxl. E.g. running a
> bootloader when creating PV VMs, running a save/restore helper when
> saving/restoring a VM, etc.
>
> > 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.
> >
>
> Nod. VMs are "daemonized", in the context of Xen. Once running,
> libvirtd can be restarted without reaping them.
Great, thanks for clarifying, this sounds fine then.
Daniel
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next prev parent reply other threads:[~2014-01-30 16:17 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-17 16:23 [PATCH 00/12] libxl: fork: SIGCHLD flexibility Ian Jackson
2014-01-17 16:23 ` [PATCH 01/12] libxl: fork: Break out checked_waitpid Ian Jackson
2014-01-17 16:23 ` [PATCH 02/12] libxl: fork: Break out childproc_reaped_ours Ian Jackson
2014-01-17 16:23 ` [PATCH 03/12] libxl: fork: Clarify docs for libxl_sigchld_owner Ian Jackson
2014-01-17 16:23 ` [PATCH 04/12] libxl: fork: Document libxl_sigchld_owner_libxl better Ian Jackson
2014-01-17 16:28 ` Ian Campbell
2014-01-17 16:23 ` [PATCH 05/12] libxl: fork: assert that chldmode is right Ian Jackson
2014-01-17 16:23 ` [PATCH 06/12] libxl: fork: Provide libxl_childproc_sigchld_occurred Ian Jackson
2014-01-17 16:24 ` [PATCH 07/12] libxl: fork: Provide ..._always_selective_reap Ian Jackson
2014-01-17 22:17 ` Jim Fehlig
2014-01-17 16:24 ` [PATCH 08/12] libxl: fork: Provide LIBXL_HAVE_SIGCHLD_SELECTIVE_REAP Ian Jackson
2014-01-17 16:24 ` [PATCH 09/12] libxl: fork: Rename sigchld handler functions Ian Jackson
2014-01-20 9:59 ` Ian Campbell
2014-01-17 16:24 ` [PATCH 10/12] libxl: fork: Break out sigchld_installhandler_core Ian Jackson
2014-01-20 9:59 ` Ian Campbell
2014-01-17 16:24 ` [PATCH 11/12] libxl: fork: Break out sigchld_sethandler_raw Ian Jackson
2014-01-20 9:58 ` Ian Campbell
2014-01-20 17:57 ` Ian Jackson
2014-01-17 16:24 ` [PATCH 12/12] libxl: fork: Share SIGCHLD handler amongst ctxs Ian Jackson
2014-01-17 18:13 ` Ian Jackson
2014-01-20 9:56 ` Ian Campbell
2014-01-21 14:40 ` Ian Jackson
2014-01-21 14:53 ` Ian Campbell
2014-01-21 15:09 ` Ian Jackson
2014-01-17 16:37 ` [PATCH 00/12] libxl: fork: SIGCHLD flexibility Ian Jackson
2014-01-17 22:29 ` Jim Fehlig
2014-01-20 18:14 ` Jim Fehlig
2014-01-21 14:46 ` Ian Jackson
2014-01-21 15:11 ` [PATCH 13/12] libxl: events: Break out libxl__pipe_nonblock, _close Ian Jackson
2014-01-21 15:11 ` [PATCH 14/12] libxl: fork: Make SIGCHLD self-pipe nonblocking Ian Jackson
2014-01-21 15:32 ` Ian Campbell
2014-01-21 15:48 ` Ian Jackson
2014-01-21 15:27 ` [PATCH 13/12] libxl: events: Break out libxl__pipe_nonblock, _close Ian Campbell
2014-01-21 15:31 ` Ian Jackson
2014-01-21 15:28 ` [PATCH 00/12] libxl: fork: SIGCHLD flexibility Ian Jackson
2014-01-22 5:32 ` Jim Fehlig
2014-01-23 4:05 ` Jim Fehlig
2014-01-23 10:56 ` Ian Jackson
2014-01-23 21:36 ` Jim Fehlig
2014-01-24 4:27 ` Jim Fehlig
2014-01-24 12:41 ` Ian Jackson
2014-01-24 12:52 ` Ian Campbell
2014-01-24 15:14 ` Ian Jackson
2014-01-24 15:18 ` Ian Jackson
2014-01-24 16:36 ` Ian Jackson
2014-01-24 16:57 ` Ian Jackson
2014-01-27 5:39 ` Jim Fehlig
2014-01-27 5:22 ` Jim Fehlig
2014-01-27 14:48 ` Ian Jackson
2014-01-28 1:39 ` [libvirt] [Xen-devel] " Jim Fehlig
2014-01-28 10:06 ` Daniel P. Berrange
2014-01-29 16:23 ` [libvirt] " Ian Jackson
2014-01-30 12:18 ` [libvirt] [Xen-devel] " Daniel P. Berrange
2014-01-30 16:14 ` Jim Fehlig
2014-01-30 16:17 ` Daniel P. Berrange [this message]
2014-01-30 16:28 ` Ian Jackson
2014-01-30 16:56 ` Jim Fehlig
2014-01-30 17:12 ` [libvirt] [Xen-devel] " Ian Jackson
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