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From: zhang fangzheng <fangzheng.zhang1003@gmail.com>
Date: Tue, 20 Feb 2024 14:25:06 +0800
Message-ID: <CA+kNDJKCbd8ygfsZYELKHjCa0BNUSvMM40zWCnkPo7Hrg=HBhQ@mail.gmail.com>
Subject: Re: [PATCH V2 0/2] Introduce slabinfo version 2.2
To: Chengming Zhou <zhouchengming@bytedance.com>
Cc: Fangzheng Zhang <fangzheng.zhang@unisoc.com>, Christoph Lameter <cl@linux.com>, 
	Pekka Enberg <penberg@kernel.org>, David Rientjes <rientjes@google.com>, 
	Joonsoo Kim <iamjoonsoo.kim@lge.com>, Andrew Morton <akpm@linux-foundation.org>, 
	Vlastimil Babka <vbabka@suse.cz>, Roman Gushchin <roman.gushchin@linux.dev>, 
	Hyeonggon Yoo <42.hyeyoo@gmail.com>, Greg KH <gregkh@linuxfoundation.org>, linux-mm@kvack.org, 
	linux-kernel@vger.kernel.org, tkjos@google.com, 
	Yuming Han <yuming.han@unisoc.com>, Chunyan Zhang <zhang.lyra@gmail.com>
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On Mon, Feb 19, 2024 at 7:29=E2=80=AFPM Chengming Zhou
<zhouchengming@bytedance.com> wrote:
>
> On 2024/2/19 11:19, Fangzheng Zhang wrote:
> > Hi all,
> >
> > This series introduces slabinfo version 2.2 to users.
> > In slabinfo V2.2, we added a slabreclaim column to
> > record whether each slab pool is of reclaim type.
> > This will be more conducive for users to obtain
> > the type of each slabdata more intuitively than through
> > the interface /sys/kernel/slab/$cache/reclaim_account.
>
> I want to recommend a better tool: drgn[1] for these tasks, instead of ch=
anging
> the output format of /proc/slabinfo, which may break existing userspace t=
ools.
>
> [1] https://drgn.readthedocs.io/en/latest/index.html#
>

Thank you very much for providing a new way.
I have the following three questions about the new tool you provided:
---- 1. From the introduction, the tool is described as an alternative
to the crash utility.
          Will the permission requirements have different effects when
used, user or userdebug?
----  2. The 'Helpers' chapter introduces the simple use of
common.memory, but there is no output example.
           It involves the use of slab objects, but it also needs to
provide a specific slab_cache_name,
           which cannot give an intuitive overall information like
proc/slabinfo.
           I guess it is difficult to achieve direct output of slab
type (reclaim or unreclaim). I don=E2=80=99t know, right?
---- 3. Regarding the supported versions, is it supported for both
arm/arm64? I don't seem to have seen any similar instructions.
Finally, I would like to express my gratitude again. This tool will be
very helpful for me in other future work.

> > And we have added an example of the output result
> > executing '> cat proc/slabinfo' in the file
> > Documentation/filesystems/proc.rst.
> >
> > Changes in v2:
> > - Modify the slabinfo version number to 2.2.
> > - Add an example of slabinfo output and future works.
> >
> > Changes in v1:
> > - Add a slabreclaim column to record type of each slab
> >   in file proc/slabinfo.
> >
> > [1] https://lore.kernel.org/linux-mm/20240131094442.28834-1-fangzheng.z=
hang@unisoc.com/
> >
> > Fangzheng Zhang (2):
> >   mm/slab: Add slabreclaim flag to slabinfo
> >   Documentation: filesystems: introduce proc/slabinfo to users
> >
> >  Documentation/filesystems/proc.rst | 33 ++++++++++++++++++++++++++++++
> >  mm/slab_common.c                   |  9 ++++----
> >  2 files changed, 38 insertions(+), 4 deletions(-)
> >