Re: [Qemu-devel] [PATCH] vl: Adjust the place of processing '-mon'

[zhanghailiang]

On 2015/3/5 1:02, Markus Armbruster wrote:
> zhanghailiang <address@hidden> writes:
>
> > From: Xiangyou Xie <address@hidden>
> >
> > If VM is configured with large size of hugepage, when startup,
> > it will consume lots of time to zero the hugepage memory in the function
> > 'os_mem_prealloc'.
> > Libvirtd will wait 30 seconds for qemu to establish the monitor,
> > If the timeout triggers, libvirtd will send TERM signal to kill qemu.
> >
> > To solve the problem, adjust the processing of '-mon' to the ahead of '-object'.
> >
> > Signed-off-by: Xiangyou Xie <address@hidden>
> > Signed-off-by: zhanghailiang <address@hidden>
> > ---
> >   vl.c | 8 ++++----
> >   1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/vl.c b/vl.c
> > index 86bdce0..d0c03fe 100644
> > --- a/vl.c
> > +++ b/vl.c
> > @@ -4000,6 +4000,10 @@ int main(int argc, char **argv, char **envp)
> >           exit(0);
> >       }
> >
> > +    if (qemu_opts_foreach(qemu_find_opts("mon"), mon_init_func, NULL, 1) != 0) 
> > {
> > +        exit(1);
> > +    }
> > +
> >       if (qemu_opts_foreach(qemu_find_opts("object"),
> >                             object_create, NULL, 0) != 0) {
> >           exit(1);
> > @@ -4154,10 +4158,6 @@ int main(int argc, char **argv, char **envp)
> >
> >       parse_numa_opts();
> >
> > -    if (qemu_opts_foreach(qemu_find_opts("mon"), mon_init_func, NULL, 1) != 0) 
> > {
> > -        exit(1);
> > -    }
> > -
> >       if (foreach_device_config(DEV_SERIAL, serial_parse) < 0)
> >           exit(1);
> >       if (foreach_device_config(DEV_PARALLEL, parallel_parse) < 0)
>
>
> Errors after monitor initialization look ugly when a monitor is on
> stdio:
>
>      $ qemu -nodefaults -monitor stdio -vga xxx
>      QEMU 2.2.50 monitor - type 'help' for more information
>      (qemu) Unknown vga type: xxx
>      $
>
> This patch initializes monitors earlier, thus makes more errors look
> ugly.  Do we care?

Hmm, i don't think it will make any difference, no matter monitor or stdio,
it is all OK, it is just error reports, let people know what's wrong.

> If not: should we initialize them even earlier?  They depend on
> character devices, so what about right after loop calling
> chardev_init_func()?

This is reasonable, will fix it like that in v2, thanks.

> Our startup is a big happy ad hoc mess.  A more organizes program would

Yes, maybe some cleanup work should be done.

> read and check configuration first (quick, can fail), then allocate
> resources (quick, can fail), then initialize (somewhat slow, failure
> unlikely).
>
> .