pub const BLOCK: usize = 8_192;Expand description
Elements a block buffer holds.
The working set is slots buffers of this size — two or three for the
benchmark kernels — so 8,192 f64 is 128 to 192 KB and stays inside a
256 KB L2. The value is not delicate: measured at 2,048 / 4,096 / 8,192 /
16,384 / 32,768 on +/ w * x and +/ ^ x over 20M rows, the whole range
lands within a few per cent of the best, because what the kernel is
really bounded by is streaming the leaves in from memory once.