On Mon 29-07-13 17:20:01, Peter Zijlstra wrote: > On Mon, Jul 29, 2013 at 04:53:08PM +0200, Michal Hocko wrote: > > Peter, for you context the lockdep splat has been reported > > here: https://lkml.org/lkml/2013/7/17/381 > > > > Minchan has proposed to workaround it by using SINGLE_DEPTH_NESTING > > https://lkml.org/lkml/2013/7/23/812 > > > > my idea was to use a separate class key for hugetlb as it is quite > > special in many ways: > > https://lkml.org/lkml/2013/7/25/277 > > > > What is the preferred way of fixing such an issue? > > The class is the safer annotation.
OK, I will use the class then. It should prevent other false positives AFAIU. > That said; it is a rather horrible issue any which way. This PMD sharing > is very unique to hugetlbfs (also is that really worth the effort these > days?) and it will make it impossible to make hugetlbfs swappable. No idea. > The other solution is to make the pmd allocation GFP_NOFS. That would be just papering over the lockdep limitation. So I would rather stick with something lockdep specific. I will cook up a patch. Thanks! -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
