Hi This implements anon_inodes_new() to create anonymous inodes. Patch #1 describes the changes to anon_inodes.c and why DRM could make great use of this. Patch #2 converts DRM core to use anon_inodes_new() instead of delayed dev_mapping initialization (but kept simple, TTM can be converted later). The idea is to get an anonymous backing inode for DRM devices without waiting for the first char-dev inode. We use it to unmap userspace mappings via unmap_mapping_range() if we have to evict buffers if GTT runs short or if the FW framebuffers are destroyed. We need the inode only once the first user-space mapping was created, but the delayed initialization causes an ugly code base and keeps inodes of char-devs around just to preserve the address_space. We actually only need the address_space, but mm core requires an corresponding file* and FS core requires mapping->host to be set (although I am not sure whether we can hit those paths with char-devs). So I went with the whole anonymous inode approach. If anyone has an idea how to use an embedded "struct address_space" inside of "drm_device" and set "dev_mapping->host" to the shared anon_inode_inode, I'd be happy to implement it. However, I didn't succeed and I am actually not sure that separate "struct address_space" are actually supported. For instance, DRM core uses code like: container_of(dev_mapping, struct inode, i_data) So I didn't spent much time on that approach. Cheers David David Herrmann (2): anon_inodes: allow external inode allocations DRM: use anon_inode instead of delayed inode init drivers/gpu/drm/drm_drv.c | 1 - drivers/gpu/drm/drm_fops.c | 24 +++-------------------- drivers/gpu/drm/drm_stub.c | 12 +++++++++++- drivers/gpu/drm/i915/i915_gem.c | 4 ++-- drivers/gpu/drm/nouveau/nouveau_gem.c | 2 +- drivers/gpu/drm/omapdrm/omap_gem.c | 7 ++++--- drivers/gpu/drm/qxl/qxl_object.c | 2 +- drivers/gpu/drm/qxl/qxl_ttm.c | 2 +- drivers/gpu/drm/radeon/radeon_object.c | 2 +- drivers/gpu/drm/radeon/radeon_ttm.c | 2 +- drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 2 +- fs/anon_inodes.c | 36 +++++++++++++++++++++++++++------- include/drm/drmP.h | 2 +- include/linux/anon_inodes.h | 1 + 14 files changed, 57 insertions(+), 42 deletions(-) -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
