From mboxrd@z Thu Jan 1 00:00:00 1970 From: Govindarajulu Varadarajan <_govind@gmx.com> Subject: [PATCH RFC net-next 2/2] net: skbuff: do not allocate emergency memory if flags is not __GFP_MEMALLOC Date: Sun, 24 Aug 2014 03:07:19 +0530 Message-ID: <1408829839-20742-3-git-send-email-_govind@gmx.com> References: <1408829839-20742-1-git-send-email-_govind@gmx.com> Cc: davem@davemloft.net, edumazet@google.com, mgorman@suse.de, Govindarajulu Varadarajan <_govind@gmx.com> To: netdev@vger.kernel.org Return-path: Received: from mout.gmx.com ([74.208.4.200]:53598 "EHLO mout.gmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751717AbaHWVhw (ORCPT ); Sat, 23 Aug 2014 17:37:52 -0400 In-Reply-To: <1408829839-20742-1-git-send-email-_govind@gmx.com> Sender: netdev-owner@vger.kernel.org List-ID: It is possible that nc->frag.page is previously allocated from emergency memory. For new alloc call, if the flags does not contain __GFP_MEMALLOC, do not return pfmemalloc memory. Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com> --- net/core/skbuff.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 51a3328..792ce89 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -364,6 +364,13 @@ recycle: atomic_set(&nc->frag.page->_count, NETDEV_PAGECNT_MAX_BIAS); nc->pagecnt_bias = NETDEV_PAGECNT_MAX_BIAS; nc->frag.offset = 0; + } else if (nc->frag.page->pfmemalloc && !(gfp_mask & __GFP_MEMALLOC)) { + if (atomic_sub_and_test(nc->pagecnt_bias, + &nc->frag.page->_count)) { + atomic_set(&nc->frag.page->_count, 1); + kfree(page_address(nc->frag.page)); + } + goto refill; } if (nc->frag.offset + fragsz > nc->frag.size) { -- 2.1.0