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    SubjectRE: [BUG] Page allocation failures with newest kernels
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    Hi Robin 

    During some of the stress tests we also came across a different warning from the arm64 page management code
    It looks like a race is detected between HW and SW marking a bit in the PTE

    Not sure it's really related but I thought it might give a clue on the issue
    http://pastebin.com/ASv19vZP

    Thanks

    Yehuda


    > -----Original Message-----
    > From: Marcin Wojtas [mailto:mw@semihalf.com]
    > Sent: Tuesday, May 31, 2016 13:30
    > To: Robin Murphy
    > Cc: linux-mm@kvack.org; linux-kernel@vger.kernel.org; linux-arm-
    > kernel@lists.infradead.org; Lior Amsalem; Thomas Petazzoni; Yehuda
    > Yitschak; Catalin Marinas; Arnd Bergmann; Grzegorz Jaszczyk; Will Deacon;
    > Nadav Haklai; Tomasz Nowicki; Gregory Clément
    > Subject: Re: [BUG] Page allocation failures with newest kernels
    >
    > Hi Robin,
    >
    > >
    > > I remember there were some issues around 4.2 with the revision of the
    > > arm64 atomic implementations affecting the cmpxchg_double() in SLUB,
    > > but those should all be fixed (and the symptoms tended to be
    > considerably more fatal).
    > > A stronger candidate would be 97303480753e (which landed in 4.4),
    > > which has various knock-on effects on the layout of SLUB internals -
    > > does fiddling with L1_CACHE_SHIFT make any difference?
    > >
    >
    > I'll check the commits, thanks. I forgot to add L1_CACHE_SHIFT was my first
    > suspect - I had spent a long time debugging network controller, which
    > stopped working because of this change - L1_CACHE_BYTES (and hence
    > NET_SKB_PAD) not fitting HW constraints. Anyway reverting it didn't help at
    > all for page alloc issue.
    >
    > Best regards,
    > Marcin
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