From e86584c5377f4219781492ca164664bce40c0090 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 12 Feb 2018 14:55:33 +0000 Subject: [PATCH] drm: Use idr_init_base(1) when using id==0 for invalid MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Use the new idr_init_base() function to create an IDR that knows id==0 is never allocated as it maps to an invalid identifier. By knowing that id==0 is invalid, the IDR can start from id=1 instead avoiding the issue of having to start each lookup from the zeroth leaf as id==0 is always unused (and thus the tree-of-bitmaps indicate that is the first available). References: 6ce711f27500 ("idr: Make 1-based IDRs more efficient") Signed-off-by: Chris Wilson Cc: Daniel Vetter Cc: Christian Konig Cc: Dave Airlie Reviewed-by: Ville Syrjälä Acked-by: Christian König as well. Link: https://patchwork.freedesktop.org/patch/msgid/20180212145533.30046-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/drm_gem.c | 4 ++-- drivers/gpu/drm/drm_syncobj.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 01f8d9481211..4975ba9a7bc8 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -98,7 +98,7 @@ drm_gem_init(struct drm_device *dev) struct drm_vma_offset_manager *vma_offset_manager; mutex_init(&dev->object_name_lock); - idr_init(&dev->object_name_idr); + idr_init_base(&dev->object_name_idr, 1); vma_offset_manager = kzalloc(sizeof(*vma_offset_manager), GFP_KERNEL); if (!vma_offset_manager) { @@ -776,7 +776,7 @@ drm_gem_open_ioctl(struct drm_device *dev, void *data, void drm_gem_open(struct drm_device *dev, struct drm_file *file_private) { - idr_init(&file_private->object_idr); + idr_init_base(&file_private->object_idr, 1); spin_lock_init(&file_private->table_lock); } diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index 0b7b0d1ad2d5..d4f4ce484529 100644 --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -546,7 +546,7 @@ static int drm_syncobj_export_sync_file(struct drm_file *file_private, void drm_syncobj_open(struct drm_file *file_private) { - idr_init(&file_private->syncobj_idr); + idr_init_base(&file_private->syncobj_idr, 1); spin_lock_init(&file_private->syncobj_table_lock); } -- 2.45.2