Re: [BUG] fatal hang untarring 90GB file, possibly writeback related.

Mel Gorman
2011-05-06T15:44:44Z

On Fri, May 06, 2011 at 08:42:24AM +0100, Mel Gorman wrote:
>
> 1. High-order allocations? You machine is using i915 and RPC, something
> neither of my test machine uses. i915 is potentially a source for
> high-order allocations. I'm attaching a perl script. Please run it as
> ./watch-highorder.pl --output /tmp/highorders.txt
> while you are running tar. When kswapd is running for about 30
> seconds, interrupt it with ctrl+c twice in quick succession and
> post /tmp/highorders.txt
>

Colin send me this information for his test case at least and I see

11932 instances order=1 normal gfp_flags=GFP_NOWARN|GFP_NORETRY|GFP_COMP|GFP_NOMEMALLOC
=> alloc_pages_current+0xa5/0x110 <ffffffff81149ef5>
=> new_slab+0x1f5/0x290 <ffffffff81153645>
=> __slab_alloc+0x262/0x390 <ffffffff81155192>
=> kmem_cache_alloc+0x115/0x120 <ffffffff81155ab5>
=> mempool_alloc_slab+0x15/0x20 <ffffffff8110e705>
=> mempool_alloc+0x59/0x140 <ffffffff8110ea49>
=> bio_alloc_bioset+0x3e/0xf0 <ffffffff811976ae>
=> bio_alloc+0x15/0x30 <ffffffff81197805>

Colin and James: Did you happen to switch from SLAB to SLUB between
2.6.37 and 2.6.38? My own tests were against SLAB which might be why I
didn't see the problem. Am restarting the tests with SLUB.

--
Mel Gorman
SUSE Labs

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