On Thu, Nov 18, 2021 at 11:26:30AM +0800, Gang Li wrote:

On 11/17/21 6:10 PM, Mel Gorman wrote:

quoted

On Wed, Nov 17, 2021 at 05:38:28PM +0800, Gang Li wrote:

quoted

If those APIs are ok with you, I will send v2 soon.

1. prctl(PR_NUMA_BALANCING, PR_SET_THP_DISABLE);

It would be (PR_SET_NUMAB_DISABLE, 1)

quoted

2. prctl(PR_NUMA_BALANCING, PR_SET_THP_ENABLE);

An enable prctl will have the same problems as
prctl(PR_NUMA_BALANCING, PR_SET_NUMA_BALANCING, 0/1) -- it should have
meaning if the numa_balancing sysctl is disabled.

quoted

3. prctl(PR_NUMA_BALANCING, PR_GET_THP);

PR_GET_NUMAB_DISABLE

How about this:

1. prctl(PR_NUMA_BALANCING, PR_SET_NUMAB_DEFAULT); //follow global
2. prctl(PR_NUMA_BALANCING, PR_SET_NUMAB_DISABLE); //disable
3. prctl(PR_NUMA_BALANCING, PR_SET_NUMAB_ENABLE);  //enable

If PR_SET_NUMAB_ENABLE enables numa balancing for a task when
kernel.numa_balancing == 0 instead of returning an error then sure.

4. prctl(PR_NUMA_BALANCING, PR_GET_NUMAB);

PR_SET_NUMAB_DISABLE/ENABLE can always have meaning whether the
numa_balancing sysctl is disabled or not,

-- 
Thanks,
Gang Li

-- 
Mel Gorman
SUSE Labs