Re: [PATCH] tools/drgn: Add script to display page state for a given PID and VADDR

[Ye Liu <ye.liu@linux.dev>]

在 2025/4/16 12:02, Paul E. McKenney 写道:
> On Tue, Apr 15, 2025 at 11:28:41PM -0400, Sweet Tea Dorminy wrote:
>>
>> On 4/15/25 10:46 PM, Ye Liu wrote:
>>> 在 2025/4/16 10:14, Andrew Morton 写道:
>>>> On Tue, 15 Apr 2025 15:50:24 +0800 Ye Liu <ye.liu@linux.dev> wrote:
>>>>
>>>>> From: Ye Liu <liuye@kylinos.cn>
>>>>>
>>>>> Introduces a new drgn script, `show_page_info.py`, which allows users
>>>>> to analyze the state of a page given a process ID (PID) and a virtual
>>>>> address (VADDR). This can help kernel developers or debuggers easily
>>>>> inspect page-related information in a live kernel or vmcore.
>>>>>
>>>>> The script extracts information such as the page flags, mapping, and
>>>>> other metadata relevant to diagnosing memory issues.
>>>>>
>>>>> Currently, there is no specific maintainer entry for `tools/drgn/` in the
>>>>> MAINTAINERS file. Therefore, this patch is sent to the general kernel and
>>>>> tools mailing lists for review.
>>>> Help.  My copy of linux has no tools/drgn/
>>> I noticed that the current upstream Linux tree doesn't contain a
>>> `tools/drgn/` directory.
>>>
>>> I'm interested in contributing a drgn script tool as well.
>>> Given that this directory does not yet exist in mainline, where would
>>> be the appropriate place to add new drgn scripts? Would it make sense
>>> to create a new `tools/drgn/` directory, or is there a preferred
>>> location for such debugging scripts?
>>>
>>> Thanks,
>>> Ye
>> I believe the traditional thing to do with new drgn scripts is to add them
>> to the contrib directory in drgn via pull request:
>> https://github.com/osandov/drgn/blob/main/contrib/README.rst
> I have an RCU-related drgn script in tools/rcu, so maybe this one should
> go in tools/mm.


To determine the most appropriate place to submit this script, I looked

into existing drgn-based tooling in the kernel tree. Several drgn scripts
have already been added under `tools/`, such as:

- `tools/sched_ext/scx_show_state.py`
- `tools/cgroup/iocost_monitor.py`
- `tools/cgroup/memcg_slabinfo.py`
- `tools/writeback/wb_monitor.py`
- `tools/rcu/rcu-cbs.py`
- `tools/workqueue/wq_dump.py`
- `tools/workqueue/wq_monitor.py`

Given this precedent, I believe it would be reasonable to place
`show_page_info.py` under `tools/mm/`, since it's focused on memory
subsystem internals and would follow a similar organizational pattern
to the above.

I'd appreciate any input on whether this is a suitable direction.
I'm happy to send the script for review once the location is agreed upon.

Thanks,  

Ye Liu