net/smc: Introduce a sysctl for setting SMC-R buffer type
This patch introduces the sysctl smcr_buf_type for setting
the type of SMC-R sndbufs and RMBs.
Valid values includes:
- SMCR_PHYS_CONT_BUFS, which means use physically contiguous
buffers for better performance and is the default value.
- SMCR_VIRT_CONT_BUFS, which means use virtually contiguous
buffers in case of physically contiguous memory is scarce.
- SMCR_MIXED_BUFS, which means first try to use physically
contiguous buffers. If not available, then use virtually
contiguous buffers.
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>