On 2021/7/27 20:07, Leon Romanovsky wrote:
> On Tue, Jul 27, 2021 at 11:27:21AM +0800, Wenpeng Liang wrote:
>> From: Xi Wang <wangxi11@xxxxxxxxxx>
>>
>> The hip09 introduces the DCA(Dynamic context attachment) feature which
>> supports many RC QPs to share the WQE buffer in a memory pool, this will
>> reduce the memory consumption when there are too many QPs are inactive.
>>
>> If a QP enables DCA feature, the WQE's buffer will not be allocated when
>> creating. But when the users start to post WRs, the hns driver will
>> allocate a buffer from the memory pool and then fill WQEs which tagged with
>> this QP's number.
>>
>> The hns ROCEE will stop accessing the WQE buffer when the user polled all
>> of the CQEs for a DCA QP, then the driver will recycle this WQE's buffer
>> to the memory pool.
>>
>> This patch adds a group of methods to support the user space register
>> buffers to a memory pool which belongs to the user context. The hns kernel
>> driver will update the pages state in this pool when the user calling the
>> post/poll methods and the user driver can get the QP's WQE buffer address
>> by the key and offset which queried from kernel.
>>
>> Signed-off-by: Xi Wang <wangxi11@xxxxxxxxxx>
>> Signed-off-by: Wenpeng Liang <liangwenpeng@xxxxxxxxxx>
>> ---
>> drivers/infiniband/hw/hns/Makefile | 2 +-
>> drivers/infiniband/hw/hns/hns_roce_dca.c | 343 ++++++++++++++++++++++++++++
>> drivers/infiniband/hw/hns/hns_roce_dca.h | 22 ++
>> drivers/infiniband/hw/hns/hns_roce_device.h | 9 +
>> drivers/infiniband/hw/hns/hns_roce_main.c | 27 ++-
>> include/uapi/rdma/hns-abi.h | 27 +++
>> 6 files changed, 427 insertions(+), 3 deletions(-)
>> create mode 100644 drivers/infiniband/hw/hns/hns_roce_dca.c
>> create mode 100644 drivers/infiniband/hw/hns/hns_roce_dca.h
>
> <...>
>
>> +static struct hns_dca_page_state *alloc_dca_states(void *pages, int count)
>> +{
>> + struct hns_dca_page_state *states;
>> +
>> + states = kcalloc(count, sizeof(*states), GFP_NOWAIT);
>
> GFP_NOWAIT ????
> Why do you use this flag while in the function before you used classic GFP_KERNEL?
>
> Thanks
> .
>
The next version will change this flag to GFP_KERNEL.
Thanks
