Re: [Qemu-devel] [PATCH] block, migration: Use qemu_madvise inplace of madvise

[Dr. David Alan Gilbert]

* Kevin Wolf (address@hidden) wrote:
> Am 17.02.2017 um 09:06 hat Pankaj Gupta geschrieben:
> >  To maintain consistency at all the places use qemu_madvise wrapper
> >  inplace of madvise call.
> > 
> > Signed-off-by: Pankaj Gupta <address@hidden>
> 
> Reviewed-by: Kevin Wolf <address@hidden>
> 
> Juan/Dave, if one of you can give an Acked-by, I can take this through
> my tree.

NACK

That's wrong; qemu_madvise can end up going through posix_madvise and
using POSIX_MADV_DONTNEED, it has different semantics to the 
madvise(MADV_DONTNEED)
and we need the semantics of madvise - i.e. it's guaranteed to throw
away the pages, where as posix_madvise *may* throw away the pages if
the kernel feels like it.

Dave

> Kevin
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK