Re: [PATCH v4 16/18] migration/rdma: add rdma_channel into Migrationstate field

From: Zheng Chuan <zhengchuan@huawei.com>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: yubihong@huawei.com, berrange@redhat.com,
	zhang.zhanghailiang@huawei.com, quintela@redhat.com,
	qemu-devel@nongnu.org, xiexiangyou@huawei.com,
	alex.chen@huawei.com, wanghao232@huawei.com
Subject: Re: [PATCH v4 16/18] migration/rdma: add rdma_channel into Migrationstate field
Date: Mon, 1 Mar 2021 20:27:03 +0800	[thread overview]
Message-ID: <8c76d7f7-b23d-25b3-4a9a-e8c1fec4a7aa@huawei.com> (raw)
In-Reply-To: <20210203201946.GY2950@work-vm>


On 2021/2/4 4:19, Dr. David Alan Gilbert wrote:
> * Chuan Zheng (zhengchuan@huawei.com) wrote:
>> Multifd RDMA is need to poll when we send data, record it.
> 
> This looks like it's trying to be the equivalent of the 'static int
> next_channel' in multifd_send_pages.
> 
> If so, why not mkae this 'multifd_channel' and make the function
> 'multifd_next_channel' and replace the code in multifd_send_pages to use
> this as well, rather than make it a special for rdma.
> 
> Dave
> 
Yes, that's a good suggestion. I'll do it in V5.

>> Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
>> ---
>>  migration/migration.c |  1 +
>>  migration/migration.h |  1 +
>>  migration/rdma.c      | 14 ++++++++++++++
>>  3 files changed, 16 insertions(+)
>>
>> diff --git a/migration/migration.c b/migration/migration.c
>> index b8f4844..47bd11d 100644
>> --- a/migration/migration.c
>> +++ b/migration/migration.c
>> @@ -1926,6 +1926,7 @@ void migrate_init(MigrationState *s)
>>      s->migration_thread_running = false;
>>      s->enabled_rdma_migration = false;
>>      s->host_port = NULL;
>> +    s->rdma_channel = 0;
>>      error_free(s->error);
>>      s->error = NULL;
>>      s->hostname = NULL;
>> diff --git a/migration/migration.h b/migration/migration.h
>> index 537ee09..5ff46e6 100644
>> --- a/migration/migration.h
>> +++ b/migration/migration.h
>> @@ -288,6 +288,7 @@ struct MigrationState {
>>  
>>      /* Need by Multi-RDMA */
>>      char *host_port;
>> +    int rdma_channel;
>>  };
>>  
>>  void migrate_set_state(int *state, int old_state, int new_state);
>> diff --git a/migration/rdma.c b/migration/rdma.c
>> index f5eb563..2097839 100644
>> --- a/migration/rdma.c
>> +++ b/migration/rdma.c
>> @@ -183,6 +183,20 @@ typedef struct {
>>  } RDMAWorkRequestData;
>>  
>>  /*
>> + * Get the multifd RDMA channel used to send data.
>> + */
>> +static int get_multifd_RDMA_channel(void)
>> +{
>> +    int thread_count = migrate_multifd_channels();
>> +    MigrationState *s = migrate_get_current();
>> +
>> +    s->rdma_channel++;
>> +    s->rdma_channel %= thread_count;
>> +
>> +    return s->rdma_channel;
>> +}
>> +
>> +/*
>>   * Negotiate RDMA capabilities during connection-setup time.
>>   */
>>  typedef struct {
>> -- 
>> 1.8.3.1
>>

-- 
Regards.
Chuan