Re: [BUG] Page allocation failures with newest kernels

From: Marcin Wojtas
Date: Tue May 31 2016 - 06:37:56 EST

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,