Re: [Qemu-devel] [PATCH v4 2/6] Migration: Split out ram part of qmp_query_migrate

[Amit Shah <amit.shah@redhat.com>]

On (Tue) 31 May 2016 [17:10:48], Dr. David Alan Gilbert wrote:
> * Amit Shah (amit.shah@redhat.com) wrote:
> > On (Tue) 17 May 2016 [13:55:51], Dr. David Alan Gilbert (git) wrote:
> > > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> > > 
> > > The RAM section of qmp_query_migrate is reasonably complex
> > > and repeated 3 times.  Split it out into a helper.
> > > 
> > > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > > Reviewed-by: Eric Blake <eblake@redhat.com>
> > > Reviwed-by: Denis V. Lunev <den@openvz.org>
> > > ---
> > >  migration/migration.c | 57 ++++++++++++++++++++-------------------------------
> > >  1 file changed, 22 insertions(+), 35 deletions(-)
> > > 
> > > diff --git a/migration/migration.c b/migration/migration.c
> > > index 991313a..bfb326d 100644
> > > --- a/migration/migration.c
> > > +++ b/migration/migration.c
> > > @@ -561,6 +561,25 @@ static void get_xbzrle_cache_stats(MigrationInfo *info)
> > >      }
> > >  }
> > >  
> > > +static void populate_ram_info(MigrationInfo *info, MigrationState *s)
> > > +{
> > > +    info->has_ram = true;
> > > +    info->ram = g_malloc0(sizeof(*info->ram));
> > > +    info->ram->transferred = ram_bytes_transferred();
> > > +    info->ram->total = ram_bytes_total();
> > > +    info->ram->duplicate = dup_mig_pages_transferred();
> > > +    info->ram->skipped = skipped_mig_pages_transferred();
> > > +    info->ram->normal = norm_mig_pages_transferred();
> > > +    info->ram->normal_bytes = norm_mig_bytes_transferred();
> > > +    info->ram->mbps = s->mbps;
> > > +    info->ram->dirty_sync_count = s->dirty_sync_count;
> > > +
> > > +    if (s->state != MIGRATION_STATUS_COMPLETED) {
> > > +        info->ram->remaining = ram_bytes_remaining();
> > > +        info->ram->dirty_pages_rate = s->dirty_pages_rate;
> > 
> > In the 'else' case, shouldn't these be set to 0?
> 
> There's no need to, see that the info->ram is allocated a few
> lines above using a g_malloc0 and so it's already all zero.

Ah, yeah :(

One of the side-effects of using gmalloc0 is valgrind (or compiler
warnings) won't be helpful when using stuff without writing to them
first.  That's why I prefer explicitly setting fields.

Anyway, I'll pick this series up, thanks!

		Amit