From a5c016d93ee24e851cd8752b014170a308f231da Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Fri, 29 Jun 2012 16:07:12 +0100 Subject: [iobuf] Relax alignment requirement for small I/O buffers iPXE currently aligns all I/O buffers on a 2kB boundary. This is overkill for transmitted packets, which are typically much smaller than 2kB. Align I/O buffers on their own size. This reduces the alignment requirement for small buffers, while preserving the guarantee that I/O buffers will never cross boundaries that might cause problems for some DMA engines. Signed-off-by: Michael Brown --- src/include/ipxe/iobuf.h | 11 ----------- 1 file changed, 11 deletions(-) (limited to 'src/include') diff --git a/src/include/ipxe/iobuf.h b/src/include/ipxe/iobuf.h index 82c8b8896..8134ae76a 100644 --- a/src/include/ipxe/iobuf.h +++ b/src/include/ipxe/iobuf.h @@ -13,17 +13,6 @@ FILE_LICENCE ( GPL2_OR_LATER ); #include #include -/** - * I/O buffer alignment - * - * I/O buffers allocated via alloc_iob() are guaranteed to be - * physically aligned to this boundary. Some cards cannot DMA across - * a 4kB boundary. With a standard Ethernet MTU, aligning to a 2kB - * boundary is sufficient to guarantee no 4kB boundary crossings. For - * a jumbo Ethernet MTU, a packet may be larger than 4kB anyway. - */ -#define IOB_ALIGN 2048 - /** * Minimum I/O buffer length * -- cgit v1.2.3-55-g7522