Re: [Bug #13319] Page allocation failures with b43 and p54usb

From: Larry Finger
Date: Sun May 17 2009 - 19:17:01 EST


Andrew Morton wrote:
>
> Well.. order-1 GFP_ATOMIC allocations are unreliable. The networking
> code should hanlde the situation and recover. I assume that is
> happening in this case?

Yes, the driver has recovered in all cases so far.

> Perhaps we did something in that code after 2.6.29 which increased the
> frequency of the order-1 allocation attempts? Maybe earlier kernels
> used order-0 all the time? Those are much more reliable.

I think something happened to change the allocation as I never saw these O(1)
failures before with these particular drivers. I put in a few test printk's and
the buffers were 700-800 bytes long, and I would not expect them to require more
than an O(0) allocation.

I pushed 2.6.30-rc6 hard for ~12 hours without any recurrence of the problem.
Given the relative infrequency of the error, this certainly does not indicate a
fix in recent code. I will be trying to force it again.

Larry

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