Messages in this thread | | | Date | Tue, 26 Jun 2012 18:55:13 +0200 | From | Sebastian Andrzej Siewior <> | Subject | Re: [PATCH 04/16] mm: allow PF_MEMALLOC from softirq context |
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On Fri, Jun 22, 2012 at 03:30:31PM +0100, Mel Gorman wrote: > This is needed to allow network softirq packet processing to make > use of PF_MEMALLOC.
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index b6c0727..5c6d9c6 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -2265,7 +2265,11 @@ gfp_to_alloc_flags(gfp_t gfp_mask) > if (likely(!(gfp_mask & __GFP_NOMEMALLOC))) { > if (gfp_mask & __GFP_MEMALLOC) > alloc_flags |= ALLOC_NO_WATERMARKS; > - else if (likely(!(gfp_mask & __GFP_NOMEMALLOC)) && !in_interrupt()) > + else if (in_serving_softirq() && (current->flags & PF_MEMALLOC)) > + alloc_flags |= ALLOC_NO_WATERMARKS; > + else if (!in_interrupt() && > + ((current->flags & PF_MEMALLOC) || > + unlikely(test_thread_flag(TIF_MEMDIE)))) > alloc_flags |= ALLOC_NO_WATERMARKS; > }
You allocate in RX path with __GFP_MEMALLOC and your sk->sk_allocation has also __GFP_MEMALLOC set. That means you should get ALLOC_NO_WATERMARKS in alloc_flags. Is this to done to avoid GFP annotations in skb_share_check() and friends on your __netif_receive_skb() path?
Sebastian
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