Re: [PATCH v2] tools/mm: Add thpmaps script to dump THP usage info

[John Hubbard <jhubbard@nvidia.com>]

On 1/16/24 00:53, Ryan Roberts wrote:
> On 15/01/2024 21:30, John Hubbard wrote:
>> On 1/15/24 07:56, Ryan Roberts wrote:
>> ...
>>   -----
>>   When run without options, cgroups v1 or v2 (depending on what is active
>>   on the system) is used in order to get a listing of all user space pids.
>>   That pid list is passed into the core script, as if the user had provided
>>   "--pids pid1 pid2 ...".
>>   -----
> 
> Agree with the sentiment; I'll add something similar. Although, I'm no longer
> using cgroups to get all the pids - I'm grabbing them from /proc.
> 
> --8<--
> When run with --pid, the user explicitly specifies the set of pids to scan. e.g.
> "--pid 10 [--pid 134 ...]". When run with --cgroup, the user passes either a v1
> or v2 cgroup and all pids that belong to the cgroup subtree are scanned. When
> run with neither --pid nor --cgroup, the full set of pids on the system is
> gathered from /proc and scanned as if the user had provided "--pid 1 --pid 2 ...".
> --8<--
> 

Sounds good.

>>
>> This reminds me that maybe a --pids options is helpful, what do you think?
> 
> How about I allow --pid to be specified multiple times? That will make the
> parsing easier (and be consistent with the way it works for --cont):
> 
> --pid 1 --pid 2 --pid 3 ...
> 

Sure, that works nicely.


thanks,
-- 
John Hubbard
NVIDIA