Re: [Qemu-devel] [PATCH v2 03/15] migration: No need to take rcu during sync_dirty_bitmap

[Peter Xu <peterx@redhat.com>]

On Mon, May 20, 2019 at 12:48:01PM +0200, Paolo Bonzini wrote:
> On 20/05/19 05:08, Peter Xu wrote:
> > cpu_physical_memory_sync_dirty_bitmap() has one RAMBlock* as
> > parameter, which means that it must be with RCU read lock held
> > already.  Taking it again inside seems redundant.  Removing it.
> > Instead comment on the functions about the RCU read lock.
> > 
> > Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> > Signed-off-by: Peter Xu <peterx@redhat.com>
> > ---
> >  include/exec/ram_addr.h | 5 +----
> >  migration/ram.c         | 1 +
> >  2 files changed, 2 insertions(+), 4 deletions(-)
> > 
> > diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
> > index 139ad79390..993fb760f3 100644
> > --- a/include/exec/ram_addr.h
> > +++ b/include/exec/ram_addr.h
> > @@ -408,6 +408,7 @@ static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start,
> >  }
> >  
> >  
> > +/* Must be with rcu read lock held */
> 
> The usual way to spell this is "Called within RCU critical section.",
> otherwise the patch looks good.

Sure, I'm switching to this with the r-b kept.

Thanks,

-- 
Peter Xu