Re: [Qemu-devel] [PATCH] numa: check for busy memory backend

[Michael S. Tsirkin]

On Mon, Jun 30, 2014 at 01:33:42PM +0800, Hu Tao wrote:
> On Sun, Jun 29, 2014 at 06:20:22PM +0300, Michael S. Tsirkin wrote:
> > On Wed, Jun 25, 2014 at 05:04:14PM +0800, Hu Tao wrote:
> > > ..to prevent one memory backend from being used by more than one numa
> > > node.
> > 
> > Thanks, but please always make the msg content self-contained
> > so it can be understood without the subject.
> > E.g. here, just drop "..to".
> > 
> > Are you sure we want this? Is there a chance sharing a backend
> > can be useful?
> 
> This patch is actually a bug fix.

It is?  What is the bug and how to reproduce it?
I am not sure we should write a ton of code to validate qemu
configuration, as long as qemu does not assert.

> Even if we will want backend sharing, we
> can do it after.

By reverting this patch? So why merge it?

> > 
> > Igor, what's your take?
> > 
> > > 
> > > Signed-off-by: Hu Tao <address@hidden>
> > > ---
> > >  numa.c | 7 +++++++
> > >  1 file changed, 7 insertions(+)
> > > 
> > > diff --git a/numa.c b/numa.c
> > > index e471afe..6c1c554 100644
> > > --- a/numa.c
> > > +++ b/numa.c
> > > @@ -279,6 +279,13 @@ void 
> > > memory_region_allocate_system_memory(MemoryRegion *mr, Object *owner,
> > >              exit(1);
> > >          }
> > >  
> > > +        if (memory_region_is_mapped(seg)) {
> > > +            char *path = 
> > > object_get_canonical_path_component(OBJECT(backend));
> > > +            error_report("memory backend %s is busy", path);
> > > +            g_free(path);
> > > +            exit(1);
> > > +        }
> > > +
> > >          memory_region_add_subregion(mr, addr, seg);
> > >          vmstate_register_ram_global(seg);
> > >          addr += size;
> > > -- 
> > > 1.9.3