Re: [PATCH 04/16] mm: allow PF_MEMALLOC from softirq context
From: Sebastian Andrzej Siewior <hidden>
Date: 2012-06-26 16:55:36
Also in:
linux-mm, lkml
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.
quoted hunk ↗ jump to hunk
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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>