Re: [PATCH 1/1] migration/multifd: solve zero page causing multiple page faults

[Peter Xu <peterx@redhat.com>]

On Tue, Apr 02, 2024 at 09:57:49AM -0300, Fabiano Rosas wrote:
> Yuan Liu <yuan1.liu@intel.com> writes:
> 
> > Implemented recvbitmap tracking of received pages in multifd.
> >
> > If the zero page appears for the first time in the recvbitmap, this
> > page is not checked and set.
> >
> > If the zero page has already appeared in the recvbitmap, there is no
> > need to check the data but directly set the data to 0, because it is
> > unlikely that the zero page will be migrated multiple times.
> >
> > Signed-off-by: Yuan Liu <yuan1.liu@intel.com>
> 
> Reviewed-by: Fabiano Rosas <farosas@suse.de>
> 

I queued it with below squashed to update the comment. I hope it works for
you.  Thanks,

===8<===
diff --git a/include/exec/ramblock.h b/include/exec/ramblock.h
index 848915ea5b..7062da380b 100644
--- a/include/exec/ramblock.h
+++ b/include/exec/ramblock.h
@@ -57,7 +57,7 @@ struct RAMBlock {
     off_t bitmap_offset;
     uint64_t pages_offset;
 
-    /* bitmap of already received pages in postcopy */
+    /* Bitmap of already received pages.  Only used on destination side. */
     unsigned long *receivedmap;
 
     /*
===8<===

-- 
Peter Xu