Re: __vmalloc with GFP_ATOMIC causes 'sleeping from invalid context'

[Nick Piggin]

Giridhar Pemmasani wrote:
> On Mon, 22 May 2006 16:14:03 +1000, Nick Piggin <nickpiggin@xxxxxxxxxxxx> said:
>
>    > Nick Piggin wrote:
>
>   >> OTOH, it doesn't seem to be particularly wrong to allow __vmalloc
>   >> GFP_ATOMIC allocations. The correct fix is to pass the gfp_mask
>   >> to kmalloc: if you're worried about breaking the API, introduce a
>   >> new __get_vm_area_node_mask() and implement __get_vm_area_node()
>   >> as a simple wrapper that passes in GFP_KERNEL.
>
>    > Oh, and __get_vm_area_node{_mask} should BUG_ON(in_interrupt());
>
> With the patch I sent earlier, this may not be required: Since
> __get_vm_area_node calls kmalloc, it should be taken care of in
> kmalloc and friends. Currently cache_alloc_debugcheck_before doesn't
> check for in_interrupt(); perhaps that is the right place to add

vmlist_lock is not irq safe. If you call it from interrupt, you can
deadlock.

--
SUSE Labs, Novell Inc.
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