Re: GFP_ATOMIC page allocation failures.

Jeff Garzik
2008-04-02T17:22:22Z

Andrew Morton wrote:
> The appropriate thing to do here is to convert known-good drivers (such as
> e1000[e]) to use __GFP_NOWARN.
>
> Unfortunately netdev_alloc_skb() went and assumed GFP_ATOMIC, but I guess
> we can dive below the covers and use __netdev_alloc_skb():
>
>
>
> From: Andrew Morton <akpm@linux-foundation.org>
>
> We get rather a lot of reports of page allocation warnings coming out of
> e1000. But this driver is know to handle them properly so let's suppress
> them.

Do you people hear what you're saying???

I respectfully but strongly disagree with this.

We do __not__ need a whitelist (__GFP_NOWARN) of drivers that handle
allocation failures properly. That's a long list, a maintenance
nightmare, and it is punishing good behavior.

It has been true for over a decade that allocations should be checked
for NULL, and GFP_ATOMIC allocations MUST be checked for NULL.

Let's not crap all over good drivers, because a few bad apples don't
have the proper checks.

Or at the very least, this TOTALLY BOGUS spew from working drivers
should not be foisted upon users. Every time a working driver complains
about this -- as in the examples here -- the value of the warning
decreases to noise.

And the solution to noise is not _more noise_ (adding 'nowarn' to every
damn driver in the kernel).

Jeff