Re: Linux 4.10-rc2 arm: dmesg flooded with alloc_contig_range: [X, Y) PFNs busy

[Vlastimil Babka]

On 01/18/2017 01:23 AM, Shuah Khan wrote:
> Hi,
> 
> dmesg floods with PFNs busy messages.
> 
> [10119.071455] alloc_contig_range: [bb900, bbc00) PFNs busy
> [10119.071631] alloc_contig_range: [bba00, bbd00) PFNs busy
> [10119.071762] alloc_contig_range: [bbb00, bbe00) PFNs busy
> [10119.071940] alloc_contig_range: [bbc00, bbf00) PFNs busy
> [10119.072039] alloc_contig_range: [bbd00, bc000) PFNs busy
> [10119.072188] alloc_contig_range: [bbe00, bc100) PFNs busy
> [10119.072301] alloc_contig_range: [bbf00, bc200) PFNs busy
> [10119.072403] alloc_contig_range: [bc000, bc300) PFNs busy
> [10119.072549] alloc_contig_range: [bc100, bc400) PFNs busy
> [10119.072584] [drm:exynos_drm_gem_create] *ERROR* failed to allocate buffer.
> 
> I think this is triggered when drm tries to allocate CMA buffers.
> I might have seen one or two messages in 4.9, but since 4.10, it
> just floods dmesg.
> 
> Is this a known problem? I am seeing this on odroid-xu4

Hi,

yes most likely it's the problem fixed by this patch in mmotm/linux-next:

http://ozlabs.org/~akpm/mmots/broken-out/mm-alloc_contig-re-allow-cma-to-compact-fs-pages.patch

> Linux odroid 4.10.0-rc2-00251-ge03c755-dirty #12 SMP PREEMPT
> Wed Jan 11 23:12:52 UTC 2017 armv7l armv7l armv7l GNU/Linux
> 
> thanks,
> -- Shuah
>