Re: [PATCH v11 3/4] tools/mm: add page_owner_filter userspace tool

["zhen.ni" <zhen.ni@easystack.cn>]

在 2026/6/25 12:50, Andrew Morton 写道:
> On Thu, 25 Jun 2026 12:31:00 +0800 Zhen Ni <zhen.ni@easystack.cn> wrote:
> 
>> Add a userspace filtering tool for page_owner that supports per-fd
>> filtering with print_mode and NUMA node filters.
> 
> Could this functionality have been built into page_owner_sort.c, or
> does that not make any sense?
> 
> 
> 
Hi,

I've considered the possibility of merging the two tools. They serve
different purposes:

- page_owner_sort: a post-processing tool for sorting/aggregating
  already-captured page_owner dumps

- page_owner_filter: a real-time filtering tool

They function like two stages in a pipeline. While there may be
opportunities to share some parsing/formatting code between the two
tools in the future, a direct merge doesn't make sense.

I believe that as page_owner_filter's functionality expands,
it could potentially replace most of page_owner_sort's features.

Looking at page_owner_sort's current interface:

Usage: ./page_owner_sort [OPTIONS] <input> <output>
-a                      Sort by memory allocation time.
-m                      Sort by total memory.
-n                      Sort by task command name.
-p                      Sort by pid.
-P                      Sort by tgid.
-s                      Sort by the stacktrace.
-t                      Sort by number of times record is seen (default).

--pid <pidlist>         Select by pid.
--tgid <tgidlist>       Select by tgid.
--name <cmdlist>        Select by command name.
--cull <rules>          Cull by user-defined rules.
--sort <order>          Specify sort order.

For example:
- Sorting by task command name (-n), PID (-p), TGID (-P), or stacktrace
   (-s) seems less useful in practice — users typically care about 
specific processes rather than sorted lists.
- Sorting by total memory (-m) or occurrence count (-t) overlaps with
   /sys/kernel/debug/page_owner_stacks functionality, which is more 
efficient.
- Filtering options (--pid, --tgid, --name, --cull) could potentially be
   implemented in page_owner_filter as well.


Thanks,
Zhen