Re: [PATCH] adjust gfp mask passed on nested vmalloc() invocation

[Jan Beulich]

>>> Hugh Dickins <hugh.dickins@xxxxxxxxxxxxx> 06.10.09 23:58 >>>
>On Mon, 5 Oct 2009, Jan Beulich wrote:
>
>> - fix a latent bug resulting from blindly or-ing in __GFP_ZERO, since
>>   the combination of this and __GFP_HIGHMEM (possibly passed into the
>>   function) is forbidden in interrupt context
>> - avoid wasting more precious resources (DMA or DMA32 pools), when
>>   being called through vmalloc_32{,_user}()
>> - explicitly allow using high memory here even if the outer allocation
>>   request doesn't allow it, unless is collides with __GFP_ZERO
>> 
>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
>
>I thought vmalloc.c was a BUG_ON(in_interrupt()) zone?
>The locking is all spin_lock stuff, not spin_lock_irq stuff.
>That's probably why your "bug" has remained "latent".

Actually, my previous reply to this was bogus, and I agree with your
statement. Hence, from a second version of the patch (depending on
your response on my question regarding the other part of your reply),
I should drop that part of the description.

Jan

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