diff options
Diffstat (limited to 'include/linux/idr.h')
| -rw-r--r-- | include/linux/idr.h | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/include/linux/idr.h b/include/linux/idr.h index 1eb755f77f2f..3c01b89aed67 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -18,12 +18,11 @@ #include <linux/rcupdate.h> /* - * We want shallower trees and thus more bits covered at each layer. 8 - * bits gives us large enough first layer for most use cases and maximum - * tree depth of 4. Each idr_layer is slightly larger than 2k on 64bit and - * 1k on 32bit. + * Using 6 bits at each layer allows us to allocate 7 layers out of each page. + * 8 bits only gave us 3 layers out of every pair of pages, which is less + * efficient except for trees with a largest element between 192-255 inclusive. */ -#define IDR_BITS 8 +#define IDR_BITS 6 #define IDR_SIZE (1 << IDR_BITS) #define IDR_MASK ((1 << IDR_BITS)-1) |