Re: [PATCH v3] tools/mm: Add script to display page state for a given PID and VADDR

Florian Weimer <[email protected]> Wed, 23 Apr 2025 11:45:53 +0200
Newsgroups org.kernel.vger.linux-debuggers,org.kernel.vger.linux-kernel,org.kernel.vger.linux-toolchains,org.kvack.linux-mm
Message-ID <[email protected]>
* Ye Liu:

> From: Ye Liu <[email protected]>
>
> 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.
>
> Output example:
> sudo ./show_page_info.py 1 0x7f43df5acf00
> PID: 1 Comm: systemd mm: 0xffff8881273bbc40
> Raw: 0017ffffc000416c ffffea00043a4508 ffffea0004381e08 ffff88810f086a70
> Raw: 0000000000000000 ffff888120c9b0c0 0000002500000007 ffff88812642c000
> User Virtual Address: 0x7f43df5acf00
> Page Address:         0xffffea00049a0b00
> Page Flags:           PG_referenced|PG_uptodate|PG_lru|PG_head|PG_active|
> 		      PG_private|PG_reported
> Page Size:            16384
> Page PFN:             0x12682c
> Page Physical:        0x12682c000
> Page Virtual:         0xffff88812682c000
> Page Refcount:        37
> Page Mapcount:        7
> Page Index:           0x0
> Page Memcg Data:      0xffff88812642c000
> Memcg Name:           init.scope
> Memcg Path:           /sys/fs/cgroup/memory/init.scope
> Page Mapping:         0xffff88810f086a70
> Page Anon/File:       File
> Page VMA:             0xffff88810e4af3b8
> VMA Start:            0x7f43df5ac000
> VMA End:              0x7f43df5b0000
> This page is part of a compound page.
> This page is the head page of a compound page.
> Head Page:            0xffffea00049a0b00
> Compound Order:       2
> Number of Pages:      4

Does this show the page access flags anywhere in the output?  If not,
would it be possible to include this information?

Thanks,
Florian