From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: [RFC 2/2] shrink size of scatterlist on common i386/x86-64 Date: Thu, 05 Jul 2007 16:14:14 -0700 Message-ID: <20070705231615.451797310@linux-foundation.org> References: <20070705231412.021359760@linux-foundation.org> Cc: netdev@vger.kernel.org To: David Miller Return-path: Received: from smtp2.linux-foundation.org ([207.189.120.14]:41609 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758538AbXGEXRk (ORCPT ); Thu, 5 Jul 2007 19:17:40 -0400 Content-Disposition: inline; filename=scatterlist-shrink.patch Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org The scatterlist only needs 16 bits for length/offset because PAGE_SIZE is 4K Signed-off-by: Stephen Hemminger --- a/include/asm-i386/scatterlist.h 2007-07-05 14:37:11.000000000 -0700 +++ b/include/asm-i386/scatterlist.h 2007-07-05 15:44:51.000000000 -0700 @@ -5,9 +5,9 @@ struct scatterlist { struct page *page; - unsigned int offset; dma_addr_t dma_address; - unsigned int length; + u16 offset; + u16 length; }; /* These macros should be used after a pci_map_sg call has been done --- a/include/asm-x86_64/scatterlist.h 2007-07-05 14:37:11.000000000 -0700 +++ b/include/asm-x86_64/scatterlist.h 2007-07-05 15:46:49.000000000 -0700 @@ -5,10 +5,10 @@ struct scatterlist { struct page *page; - unsigned int offset; - unsigned int length; dma_addr_t dma_address; unsigned int dma_length; + u16 offset; + u16 length; }; #define ISA_DMA_THRESHOLD (0x00ffffff) -- Stephen Hemminger