Re: [PATCH v3 0/8] mm/page_owner: Add PID/TGID/COMM and cgroup filtering

["David Hildenbrand (Arm)" <david@kernel.org>]

On 9/7/26 10:26, Zhen Ni wrote:
> This patch series adds process and memory cgroup filtering support to
> page_owner. Following the previous series that introduced print_mode and
> NUMA node filters:
>   https://lore.kernel.org/linux-mm/20260707115411.1714314-1-zhen.ni@easystack.cn/
> 
> This series adds filtering capabilities to page_owner, allowing users to
> filter output by specific processes and memory cgroups. Users can now
> filter page_owner output by PID, TGID, COMM (with wildcard support), and
> memory cgroup path. This makes page_owner debugging more focused and
> efficient for tracking memory allocations in specific contexts.
> 
> Targeted filtering provides significant performance benefits on large memory
> servers by reducing both execution time and output size. By filtering at the
> kernel level before reading, only relevant page allocations are processed,
> dramatically reducing the amount of data that needs to be handled in userspace.

page_owner is used for debugging. Why do we have to add kernel code to make it
faster?

How much faster are we talking about?

Or are there other limits to actually implementing it without kernel pre-filtering?

-- 
Cheers,

David