From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f43.google.com (mail-pa0-f43.google.com [209.85.220.43]) by kanga.kvack.org (Postfix) with ESMTP id 9181382BDC for ; Thu, 25 Sep 2014 16:34:40 -0400 (EDT) Received: by mail-pa0-f43.google.com with SMTP id kx10so11601051pab.16 for ; Thu, 25 Sep 2014 13:34:40 -0700 (PDT) Received: from mga02.intel.com (mga02.intel.com. [134.134.136.20]) by mx.google.com with ESMTP id rz7si5681479pab.123.2014.09.25.13.34.38 for ; Thu, 25 Sep 2014 13:34:38 -0700 (PDT) From: Matthew Wilcox Subject: [PATCH v11 21/21] brd: Rename XIP to DAX Date: Thu, 25 Sep 2014 16:33:38 -0400 Message-Id: <1411677218-29146-22-git-send-email-matthew.r.wilcox@intel.com> In-Reply-To: <1411677218-29146-1-git-send-email-matthew.r.wilcox@intel.com> References: <1411677218-29146-1-git-send-email-matthew.r.wilcox@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Matthew Wilcox , Matthew Wilcox From: Matthew Wilcox Since this is relating to FS_XIP, not KERNEL_XIP, it should be called DAX instead of XIP. Signed-off-by: Matthew Wilcox --- drivers/block/Kconfig | 13 +++++++------ drivers/block/brd.c | 14 +++++++------- fs/Kconfig | 4 ++-- 3 files changed, 16 insertions(+), 15 deletions(-) diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig index 014a1cf..1b8094d 100644 --- a/drivers/block/Kconfig +++ b/drivers/block/Kconfig @@ -393,14 +393,15 @@ config BLK_DEV_RAM_SIZE The default value is 4096 kilobytes. Only change this if you know what you are doing. -config BLK_DEV_XIP - bool "Support XIP filesystems on RAM block device" - depends on BLK_DEV_RAM +config BLK_DEV_RAM_DAX + bool "Support Direct Access (DAX) to RAM block devices" + depends on BLK_DEV_RAM && FS_DAX default n help - Support XIP filesystems (such as ext2 with XIP support on) on - top of block ram device. This will slightly enlarge the kernel, and - will prevent RAM block device backing store memory from being + Support filesystems using DAX to access RAM block devices. This + avoids double-buffering data in the page cache before copying it + to the block device. Answering Y will slightly enlarge the kernel, + and will prevent RAM block device backing store memory from being allocated from highmem (only a problem for highmem systems). config CDROM_PKTCDVD diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 78fe510..97c55db 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -97,13 +97,13 @@ static struct page *brd_insert_page(struct brd_device *brd, sector_t sector) * Must use NOIO because we don't want to recurse back into the * block or filesystem layers from page reclaim. * - * Cannot support XIP and highmem, because our ->direct_access - * routine for XIP must return memory that is always addressable. - * If XIP was reworked to use pfns and kmap throughout, this + * Cannot support DAX and highmem, because our ->direct_access + * routine for DAX must return memory that is always addressable. + * If DAX was reworked to use pfns and kmap throughout, this * restriction might be able to be lifted. */ gfp_flags = GFP_NOIO | __GFP_ZERO; -#ifndef CONFIG_BLK_DEV_XIP +#ifndef CONFIG_BLK_DEV_RAM_DAX gfp_flags |= __GFP_HIGHMEM; #endif page = alloc_page(gfp_flags); @@ -369,7 +369,7 @@ static int brd_rw_page(struct block_device *bdev, sector_t sector, return err; } -#ifdef CONFIG_BLK_DEV_XIP +#ifdef CONFIG_BLK_DEV_RAM_DAX static long brd_direct_access(struct block_device *bdev, sector_t sector, void **kaddr, unsigned long *pfn, long size) { @@ -388,6 +388,8 @@ static long brd_direct_access(struct block_device *bdev, sector_t sector, * file happens to be mapped to the next page of physical RAM */ return PAGE_SIZE; } +#else +#define brd_direct_access NULL #endif static int brd_ioctl(struct block_device *bdev, fmode_t mode, @@ -428,9 +430,7 @@ static const struct block_device_operations brd_fops = { .owner = THIS_MODULE, .rw_page = brd_rw_page, .ioctl = brd_ioctl, -#ifdef CONFIG_BLK_DEV_XIP .direct_access = brd_direct_access, -#endif }; /* diff --git a/fs/Kconfig b/fs/Kconfig index a9eb53d..117900f 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -34,7 +34,7 @@ source "fs/btrfs/Kconfig" source "fs/nilfs2/Kconfig" config FS_DAX - bool "Direct Access support" + bool "Direct Access (DAX) support" depends on MMU help Direct Access (DAX) can be used on memory-backed block devices. @@ -45,7 +45,7 @@ config FS_DAX If you do not have a block device that is capable of using this, or if unsure, say N. Saying Y will increase the size of the kernel - by about 2kB. + by about 5kB. endif # BLOCK -- 2.1.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org