Re: Re : .... get_page_from_freelist : MInority Suggestion to acceptGFP_NOFAIL accept during boot

From: David Rientjes
Date: Fri Jul 03 2009 - 05:01:26 EST


On Thu, 2 Jul 2009, Mitchell Erblich wrote:

> Group,
>
>
> If I may suggest a minority opinion about the depreciating of the
> GFP_NOFAIL flag..
>
> I saw no discussion on the acceptance of using this flag during boot
> and shortly
> after boot.
>
> Many kernel structures require memory and thus should guarantee memory
> before they continue.
>
> As Linux is moved within embedded environments with smaller amounts of
> physical memory, the chance that earlier mem failures becomes higher.
>
> For this logic alone, my minority opinion is to not depreciate the
> GFP_NOFAIL flag.
>

I'm confused by your request because all allocations with orders under
PAGE_ALLOC_COSTLY_ORDER are inherently __GFP_NOFAIL and those that are not
can easily implement the same behavior in the caller:

struct page *page;
do {
page = alloc_pages(...);
} while (!page);

Hopefully something could be done to ensure the next call to alloc_pages()
would be more likely to succeed, but __GFP_NOFAIL doesn't provide that
anyway.
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