Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755181AbbEGKk5 (ORCPT ); Thu, 7 May 2015 06:40:57 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:47492 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752034AbbEGJrW (ORCPT ); Thu, 7 May 2015 05:47:22 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Eric Dumazet , "David S. Miller" , Luis Henriques Subject: [PATCH 3.16.y-ckt 039/180] net: do not deplete pfmemalloc reserve Date: Thu, 7 May 2015 10:44:08 +0100 Message-Id: <1430991989-23170-40-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1430991989-23170-1-git-send-email-luis.henriques@canonical.com> References: <1430991989-23170-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2008 Lines: 58 3.16.7-ckt11 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit 79930f5892e134c6da1254389577fffb8bd72c66 upstream. build_skb() should look at the page pfmemalloc status. If set, this means page allocator allocated this page in the expectation it would help to free other pages. Networking stack can do that only if skb->pfmemalloc is also set. Also, we must refrain using high order pages from the pfmemalloc reserve, so __page_frag_refill() must also use __GFP_NOMEMALLOC for them. Under memory pressure, using order-0 pages is probably the best strategy. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller [ luis: backported to 3.16: used davem's backport to 3.14 ] Signed-off-by: Luis Henriques --- net/core/skbuff.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index fe07faaed256..0f27eae2ccc1 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -309,7 +309,11 @@ struct sk_buff *build_skb(void *data, unsigned int frag_size) memset(skb, 0, offsetof(struct sk_buff, tail)); skb->truesize = SKB_TRUESIZE(size); - skb->head_frag = frag_size != 0; + if (frag_size) { + skb->head_frag = 1; + if (virt_to_head_page(data)->pfmemalloc) + skb->pfmemalloc = 1; + } atomic_set(&skb->users, 1); skb->head = data; skb->data = data; @@ -352,7 +356,8 @@ refill: gfp_t gfp = gfp_mask; if (order) - gfp |= __GFP_COMP | __GFP_NOWARN; + gfp |= __GFP_COMP | __GFP_NOWARN | + __GFP_NOMEMALLOC; nc->frag.page = alloc_pages(gfp, order); if (likely(nc->frag.page)) break; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/