From 7a862fbbdec665190c5ef298c0c6ec9f3915cf45 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 23 Oct 2017 10:24:45 -0700 Subject: brd: remove dax support DAX support in brd is awkward because its backing page frames are distinct from the ones provided by pmem, dcssblk, or axonram. We need pfn_t_devmap() entries to fully support DAX, and the limited DAX support for pfn_t_special() page frames is not interesting for brd when pmem is already a superset of brd. Lastly, brd is the only dax capable driver that may sleep in its ->direct_access() implementation. So it causes a global burden with no net gain of kernel functionality. For all these reasons, remove DAX support. Cc: Jens Axboe Cc: Matthew Wilcox Cc: Ross Zwisler Reviewed-by: Christoph Hellwig Signed-off-by: Dan Williams --- drivers/block/Kconfig | 12 ------------ 1 file changed, 12 deletions(-) (limited to 'drivers/block/Kconfig') diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig index 2dfe99b328f8..da8bf0268ade 100644 --- a/drivers/block/Kconfig +++ b/drivers/block/Kconfig @@ -297,7 +297,6 @@ config BLK_DEV_SX8 config BLK_DEV_RAM tristate "RAM block device support" - select DAX if BLK_DEV_RAM_DAX ---help--- Saying Y here will allow you to use a portion of your RAM memory as a block device, so that you can make file systems on it, read and @@ -333,17 +332,6 @@ config BLK_DEV_RAM_SIZE The default value is 4096 kilobytes. Only change this if you know what you are doing. -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 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 tristate "Packet writing on CD/DVD media (DEPRECATED)" depends on !UML -- cgit v1.2.3