Messages in this thread | | | From | Linus Torvalds <> | Date | Thu, 20 Dec 2012 14:26:43 -0800 | Subject | Re: [PATCH] ksm: make rmap walks more scalable |
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On Thu, Dec 20, 2012 at 1:49 PM, Sasha Levin <sasha.levin@oracle.com> wrote: > On 12/19/2012 08:44 PM, Hugh Dickins wrote: >> The rmap walks in ksm.c are like those in rmap.c: >> they can safely be done with anon_vma_lock_read(). >> >> Signed-off-by: Hugh Dickins <hughd@google.com> >> --- > > Hi Hugh, > > This patch didn't fix the ksm oopses I'm seeing. > > This is with both patches applied:
Looks like another NULL mm pointer in ksmd.. Hugh fixed one in 2832bc19f666 ("sched: numa: ksm: fix oops in task_numa_placment()"), this looks like more of the same.
At a guess, it looks like get_mergeable_page() has a rmap_item with no mm. No idea how that happened. Hugh? Some race due to something that depended on the mmap_sem being exclusive, rather than for read-ownership?
Linus
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