Re: [PATCH RFC 00/15] mm: memory book keeping and lru_lock splitting

Hugh Dickins
2012-02-18T07:14:30Z

On Sat, 18 Feb 2012, Konstantin Khlebnikov wrote:
> Hugh Dickins wrote:
> > On Thu, 16 Feb 2012, Hugh Dickins wrote:
> > >
> > > Yours are not the only patches I was testing in that tree, I tried to
> > > gather several other series which I should be reviewing if I ever have
> > > time: Kamezawa-san's page cgroup diet 6, Xiao Guangrong's 4 prio_tree
> > > cleanups, your 3 radix_tree changes, your 6 shmem changes, your 4 memcg
> > > miscellaneous, and then your 15 books.
> > >
> > > The tree before your final 15 did well under pressure, until I tried to
> > > rmdir one of the cgroups afterwards: then it crashed nastily, I'll have
> > > to bisect into that, probably either Kamezawa's or your memcg changes.
> >
> > So far I haven't succeeded in reproducing that at all: it was real,
> > but obviously harder to get than I assumed - indeed, no good reason
> > to associate it with any of those patches, might even be in 3.3-rc.
> >
> > It did involve a NULL pointer dereference in mem_cgroup_page_lruvec(),
> > somewhere below compact_zone() - but repercussions were causing the
> > stacktrace to scroll offscreen, so I didn't get good details.
>
> There some stupid bugs in my v1 patchset, it shouldn't works at all.
> I did not expect that someone will try to use it. I sent it just to discuss.

Yes, but as I said, that bug appeared before I put your patchset (the 15) on.

Hugh