Re: [Bug #14141] order 2 page allocation failures in iwlagn

[reinette chatre]

On Wed, 2009-10-14 at 19:02 -0700, Frans Pop wrote:
> On Wednesday 14 October 2009, reinette chatre wrote:
> > We do queue the GFP_KERNEL allocations when there are only a few buffers
> > remaining in the queue (8 right now) ... maybe we can make this higher?
> 
> I've tried increasing it to 50. Here's the result for a single test:
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 25 free buffers remaining.
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 48 free buffers remaining.
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 0 free buffers remaining.
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 0 free buffers remaining.
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 48 free buffers remaining.
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 0 free buffers remaining.
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 48 free buffers remaining.
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 0 free buffers remaining.
> __ratelimit: 1 callbacks suppressed
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 0 free buffers remaining.
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 0 free buffers remaining.
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 0 free buffers remaining.
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 0 free buffers remaining.
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 0 free buffers remaining.
> __ratelimit: 97 callbacks suppressed
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 44 free buffers remaining.
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 0 free buffers remaining.
> iwlagn 0000:10:00.0: Failed to allocate SKB buffer with GFP_ATOMIC. Only 0 free buffers remaining.
> 
> This is with current mainline (v2.6.32-rc4-149-ga3ccf63).

> The log file timestamps don't tell much as the logging gets delayed,
> so they all end up at the same time. Maybe I should enable the kernel
> timestamps so we can see how far apart these failures are.

If you can get accurate timing it will be very useful. I am interested
to see how quickly it goes from "48 free buffers" to "0 free buffers".

Thank you

Reinette



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