| Message ID | 20230629213248.3184245-2-yzhong@purestorage.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | RDMA/mlx5: align MR mem allocation size to power-of-two | expand |
diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c index 2017ede100a6..92f35fafb2c0 100644 --- a/drivers/infiniband/hw/mlx5/mr.c +++ b/drivers/infiniband/hw/mlx5/mr.c @@ -1766,6 +1766,11 @@ mlx5_alloc_priv_descs(struct ib_device *device, int ret; add_size = max_t(int, MLX5_UMR_ALIGN - ARCH_KMALLOC_MINALIGN, 0); + if (is_power_of_2(MLX5_UMR_ALIGN) && add_size) { + int end = max_t(int, MLX5_UMR_ALIGN, roundup_pow_of_two(size)); + + add_size = min_t(int, end - size, add_size); + } mr->descs_alloc = kzalloc(size + add_size, GFP_KERNEL); if (!mr->descs_alloc)
The MR memory allocation requests extra bytes to guarantee that there is enough space to find the memory aligned to MLX5_UMR_ALIGN. For power-of-two sizes, the alignment can be guaranteed by kmalloc() according to commit 59bb47985c1d ("mm, sl[aou]b: guarantee natural alignment for kmalloc(power-of-two)"). So if target alignment is power-of-two and adding the extra bytes crosses a power-of-two boundary, use the next power-of-two as the allocation size. Signed-off-by: Yuanyuan Zhong <yzhong@purestorage.com> --- drivers/infiniband/hw/mlx5/mr.c | 5 +++++ 1 file changed, 5 insertions(+)