diff options
| -rw-r--r-- | Documentation/filesystems/dax.txt | 3 | ||||
| -rw-r--r-- | fs/Kconfig | 1 |
2 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/filesystems/dax.txt b/Documentation/filesystems/dax.txt index be376d91d058..baf41118660d 100644 --- a/Documentation/filesystems/dax.txt +++ b/Documentation/filesystems/dax.txt @@ -82,6 +82,9 @@ Shortcomings Even if the kernel or its modules are stored on a filesystem that supports DAX on a block device that supports DAX, they will still be copied into RAM. +The DAX code does not work correctly on architectures which have virtually +mapped caches such as ARM, MIPS and SPARC. + Calling get_user_pages() on a range of user memory that has been mmaped from a DAX file will fail as there are no 'struct page' to describe those pages. This problem is being worked on. That means that O_DIRECT diff --git a/fs/Kconfig b/fs/Kconfig index 5331497d5b25..ec35851e5b71 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -36,6 +36,7 @@ source "fs/nilfs2/Kconfig" config FS_DAX bool "Direct Access (DAX) support" depends on MMU + depends on !(ARM || MIPS || SPARC) help Direct Access (DAX) can be used on memory-backed block devices. If the block device supports DAX and the filesystem supports DAX, |