Re: s390 hugetlb oops with libhugetlbfs test-suite

From: Nishanth Aravamudan
Date: Tue Aug 05 2008 - 12:15:18 EST


On 05.08.2008 [17:49:32 +0200], Gerald Schaefer wrote:
> On Tue, 2008-07-29 at 14:46 -0700, Nishanth Aravamudan wrote:
> > Beyond the counters case, I saw one other issue on s390 (haven't
> > confirmed if it happens anywhere else), the icache-hygiene test, when
> > run manually a few times, will fail every so often claiming that one of
> > the mmap()s returned ENOMEM. I haven't had time to track that down yet,
> > but it might be because of the address space layout and the size of the
> > hugepage on s390.
>
> I have posted a patch that will fix the counters oops.

I'm guessing you've tested it, but I will go ahead and do so and
confirm.

> So far, I could not reproduce the icache-hygiene problem, did you use
> hardware large page support or software emulation?

It was the same box that produce the counters oops, so I'm guessing
software emulation?

> But I probably noticed a similar one:
>
> map_high_truncate_2 (32): FAIL mmap() 1: Cannot allocate memory
>
> That one should be because of the 31-bit address space layout on s390,
> as it tries to mmap too much (1.5GB).

Ah, that could easily be.

> I also noticed that task-size-overrun (64) seems to hang up on my
> system, I can only continue after ctrl+c, can you verify that?

I think that happens, yes, because of how many mmap's it takes to run
into the topmost mapping. I'll check it out.

Thanks,
Nish

--
Nishanth Aravamudan <nacc@xxxxxxxxxx>
IBM Linux Technology Center
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