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Date: Thu, 7 Dec 2017 12:30:25 +0300
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Alan Stern <stern@rowland.harvard.edu>,
        SF Markus Elfring <elfring@users.sourceforge.net>,
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Subject: Re: USB: hub: Delete an error message for a failed memory allocation
 in usb_hub_clear_tt_buffer()
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On Thu, Dec 07, 2017 at 09:45:38AM +0100, Geert Uytterhoeven wrote:
> >
> > Small allocations never fail in the current kernel.
> 
> A few comments (this is in response to a patch from Markus, so there have
> to be lots of questions and uncertainties ;-)
> 1. In the current kernel. What about the future?

Right.  No one can predict.  And the small allocations don't fail rule
causes some problems.

> 2. If a small allocation cannot fail, what happens if the small memory slab
>    is exhausted? A new page must be allocated, which will trigger an OOM,
>    and some other part of the system will be killed and fail.

Right.


> 3. This driver uses GFP_ATOMIC, is that guaranteed to succeed? I think not.
> 

Right again.  I was missing the first email in the thread because of my
email filters so I didn't see this was atomic.

regards,
dan carpenter