From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: [PATCH] skbuff: remove unused dma_head & dma_maps fields Date: Tue, 23 Mar 2010 23:40:50 -0700 Message-ID: <20100324064049.32298.87859.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, gospo@redhat.com, Alexander Duyck , Jeff Kirsher To: davem@davemloft.net Return-path: Received: from qmta11.westchester.pa.mail.comcast.net ([76.96.59.211]:48877 "EHLO QMTA11.westchester.pa.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751891Ab0CXGlJ (ORCPT ); Wed, 24 Mar 2010 02:41:09 -0400 Sender: netdev-owner@vger.kernel.org List-ID: From: Alexander Duyck The dma map fields in the skb_shared_info structure no longer has any users and can be dropped since it is making the skb_shared_info unecessarily larger. Running slabtop show that we were using 4K slabs for the skb->head on x86_64 w/ an allocation size of 1522. It turns out that the dma_head and dma_maps array made skb_shared large enough that we had crossed over the 2k boundary with standard frames and as such we were using 4k blocks of memory for all skbs. Signed-off-by: Alexander Duyck Signed-off-by: Jeff Kirsher --- include/linux/skbuff.h | 6 ------ 1 files changed, 0 insertions(+), 6 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 03f816a..124f90c 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -190,9 +190,6 @@ struct skb_shared_info { atomic_t dataref; unsigned short nr_frags; unsigned short gso_size; -#ifdef CONFIG_HAS_DMA - dma_addr_t dma_head; -#endif /* Warning: this field is not always filled in (UFO)! */ unsigned short gso_segs; unsigned short gso_type; @@ -201,9 +198,6 @@ struct skb_shared_info { struct sk_buff *frag_list; struct skb_shared_hwtstamps hwtstamps; skb_frag_t frags[MAX_SKB_FRAGS]; -#ifdef CONFIG_HAS_DMA - dma_addr_t dma_maps[MAX_SKB_FRAGS]; -#endif /* Intermediate layers must ensure that destructor_arg * remains valid until skb destructor */ void * destructor_arg;