Messages in this thread | | | Date | Tue, 24 Apr 2012 14:35:10 +0900 | From | Minchan Kim <> | Subject | Re: [RFC] propagate gfp_t to page table alloc functions |
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On 04/24/2012 02:16 PM, KAMEZAWA Hiroyuki wrote:
> (2012/04/23 17:55), Minchan Kim wrote: > >> As I test some code, I found a problem about deadlock by lockdep. >> The reason I saw the message is __vmalloc calls map_vm_area which calls >> pud/pmd_alloc without gfp_t. so although we call __vmalloc with >> GFP_ATOMIC or GFP_NOIO, it ends up allocating pages with GFP_KERNEL. >> The should be a BUG. This patch fixes it by passing gfp_to to low page >> table allocate functions. >> >> Signed-off-by: Minchan Kim <minchan@kernel.org> > > > Hmm ? vmalloc should support GFP_ATOMIC ?
I'm not sure but alloc_large_system_hash already has used. And it's not specific on GFP_ATOMIC. We have to care of GFP_NOFS and GFP_NOIO to prevent deadlock on reclaim context. There are some places to use GFP_NOFS and we don't emit any warning message in case of that.
> > And, do we need to change all pud_,pgd_,pmd_,pte_alloc() for users pgtables ?
Maybe.
-- Kind regards, Minchan Kim
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