Re: [PATCH for-next] RDMA/hns: Create CQ with selected CQN for bank load balance

[liweihang <liweihang@huawei.com>]

On 2021/1/4 15:06, Leon Romanovsky wrote:
> On Mon, Jan 04, 2021 at 02:35:15PM +0800, Weihang Li wrote:
>> From: Yangyang Li <liyangyang20@huawei.com>
>>
>> In order to improve performance by balancing the load between different
>> banks of cache, the CQC cache is desigend to choose one of 4 banks
>> according to lower 2 bits of CQN. The hns driver needs to count the number
>> of CQ on each bank and then assigns the CQ being created to the bank with
>> the minimum load first.
>>
>> Signed-off-by: Yangyang Li <liyangyang20@huawei.com>
>> Signed-off-by: Weihang Li <liweihang@huawei.com>
>> ---
>>  drivers/infiniband/hw/hns/hns_roce_cq.c     | 114 +++++++++++++++++++++++-----
>>  drivers/infiniband/hw/hns/hns_roce_device.h |  10 ++-
>>  drivers/infiniband/hw/hns/hns_roce_main.c   |   8 +-
>>  3 files changed, 104 insertions(+), 28 deletions(-)
>>
>> diff --git a/drivers/infiniband/hw/hns/hns_roce_cq.c b/drivers/infiniband/hw/hns/hns_roce_cq.c
>> index 8533fc2..00350a3 100644
>> --- a/drivers/infiniband/hw/hns/hns_roce_cq.c
>> +++ b/drivers/infiniband/hw/hns/hns_roce_cq.c
>> @@ -38,11 +38,74 @@
>>  #include "hns_roce_hem.h"
>>  #include "hns_roce_common.h"
>>
> 
> <...>
> 
>> +	id = ida_alloc_range(&bank->ida, bank->min, bank->max, GFP_ATOMIC);
> 
> Do you create CQ in atomic context?
> It is probably GFP_KERNEL and not GFP_ATOMIC.
> 
> Thanks
> 

Hi Leon,

Thanks for your reminder, we should use GFP_KERNEL and the spin lock of banks
needs to be changed to mutex lock.

Weihang