Messages in this thread | | | Date | Wed, 29 Aug 2012 14:41:40 +0300 | From | Haggai Eran <> | Subject | Re: [patch v3.6] mm, slab: lock the correct nodelist after reenabling irqs |
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On 29/08/2012 05:57, David Rientjes wrote: > On Tue, 28 Aug 2012, Haggai Eran wrote: > >> Hi, >> >> I believe I have encountered a bug in kernel 3.6-rc3. It starts with the >> assertion in mm/slab.c:2629 failing, and then the system hangs. I can >> reproduce this bug by running a large compilation (compiling the kernel >> for instance). >> >> Here's what I see in netconsole: >>> ------------[ cut here ]------------ >>> kernel BUG at mm/slab.c:2629! >>> invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC >> I'm attaching netconsole logs I got with kernel 3.6-rc1, which contain a >> little more details after the crash, but for some reason netconsole >> didn't capture the full stack trace of the assertion. I caught a glimpse >> at the console and I saw RIP was at cache_alloc_refill. >> > It only gets called from cache_alloc_refill(). > > Looks like a problem in 072bb0aa5e0 ("mm: sl[au]b: add knowledge of > PFMEMALLOC reserve pages"). cache_grow() can reenable irqs which allows > this to be scheduled on a different cpu, possibly with a different node. > So it turns out that we lock the wrong node's list_lock because we don't > check the new node id when irqs are disabled again. > > I doubt you can reliably reproduce this, but the following should fix the > issue. Your patch did solve the issue. Thanks!
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