Re: [Qemu-devel] [PATCH] migration/ram.c: Fix codes conflict about bitmap_mutex

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Zhang, Chen (chen.zhang@intel.com) wrote:
> Ping~  Anyone have comments about this patch?

No, it looks good to me, we need to get it merged.


Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> Thanks
> Zhang Chen
> 
> 
> > -----Original Message-----
> > From: Wang, Wei W
> > Sent: Monday, April 1, 2019 5:12 PM
> > To: Zhang, Chen <chen.zhang@intel.com>; Zhang Chen
> > <zhangckid@gmail.com>; Dr. David Alan Gilbert <dgilbert@redhat.com>; Juan
> > Quintela <quintela@redhat.com>; qemu-dev <qemu-devel@nongnu.org>
> > Subject: Re: [PATCH] migration/ram.c: Fix codes conflict about bitmap_mutex
> > 
> > On 03/30/2019 06:29 AM, Zhang Chen wrote:
> > > From: Zhang Chen <chen.zhang@intel.com>
> > >
> > > I found upstream codes conflict with COLO and lead to crash, and I
> > > located to this patch:
> > >
> > > commit 386a907b37a9321bc5d699bc37104d6ffba1b34d
> > > Author: Wei Wang <wei.w.wang@intel.com>
> > > Date:   Tue Dec 11 16:24:49 2018 +0800
> > >
> > > migration: use bitmap_mutex in migration_bitmap_clear_dirty
> > >
> > > My colleague Wei's patch add bitmap_mutex in
> > > migration_bitmap_clear_dirty, but COLO didn't initialize the
> > > bitmap_mutex. So we always get an error when COLO start up. like that:
> > > qemu-system-x86_64: util/qemu-thread-posix.c:64: qemu_mutex_lock_impl:
> > Assertion `mutex->initialized' failed.
> > >
> > > This patch add the bitmap_mutex initialize and destroy in COLO
> > > lifecycle.
> > >
> > > Signed-off-by: Zhang Chen <chen.zhang@intel.com>
> > > ---
> > >   migration/ram.c | 2 ++
> > >   1 file changed, 2 insertions(+)
> > >
> > > diff --git a/migration/ram.c b/migration/ram.c index
> > > d7f8fe45a8..f68beeeeff 100644
> > > --- a/migration/ram.c
> > > +++ b/migration/ram.c
> > > @@ -3918,6 +3918,7 @@ int colo_init_ram_cache(void)
> > >       }
> > >       ram_state = g_new0(RAMState, 1);
> > >       ram_state->migration_dirty_pages = 0;
> > > +    qemu_mutex_init(&ram_state->bitmap_mutex);
> > >       memory_global_dirty_log_start();
> > >
> > >       return 0;
> > > @@ -3956,6 +3957,7 @@ void colo_release_ram_cache(void)
> > >       }
> > >
> > >       rcu_read_unlock();
> > > +    qemu_mutex_destroy(&ram_state->bitmap_mutex);
> > >       g_free(ram_state);
> > >       ram_state = NULL;
> > >   }
> > 
> > Reviewed-by: Wei Wang <wei.w.wang@intel.com>
> > 
> > Best,
> > Wei
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK