From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx128.postini.com [74.125.245.128]) by kanga.kvack.org (Postfix) with SMTP id 0EB346B005A for ; Tue, 26 Jun 2012 12:55:34 -0400 (EDT) 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 Message-ID: <20120626165513.GD6509@breakpoint.cc> References: <1340375443-22455-1-git-send-email-mgorman@suse.de> <1340375443-22455-5-git-send-email-mgorman@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1340375443-22455-5-git-send-email-mgorman@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Andrew Morton , Linux-MM , Linux-Netdev , LKML , David Miller , Neil Brown , Peter Zijlstra , Mike Christie , Eric B Munson , Eric Dumazet 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 -- 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: email@kvack.org