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

Hugh Dickins
2012-02-18T02:14:06Z

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.

Hugh