From: Pasha Tatashin <pasha.tatashin@soleen.com>
To: Zhu Yanjun <yanjun.zhu@linux.dev>
Cc: akpm@linux-foundation.org, brauner@kernel.org, corbet@lwn.net,
graf@amazon.com, jgg@ziepe.ca, linux-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-mm@kvack.org,
masahiroy@kernel.org, ojeda@kernel.org, pratyush@kernel.org,
rdunlap@infradead.org, rppt@kernel.org, tj@kernel.org
Subject: Re: [PATCH v9 1/9] kho: make debugfs interface optional
Date: Fri, 7 Nov 2025 07:02:53 -0500 [thread overview]
Message-ID: <CA+CK2bC_+repP-q183hjAuYYB2-Yx7fr_U3zr2cxysAWx5hzpg@mail.gmail.com> (raw)
In-Reply-To: <CA+CK2bDSvtuwrrXGOC07Rj42yGFHWR4Sse7Q5z1z8f1ZFHWQ2Q@mail.gmail.com>
On Fri, Nov 7, 2025 at 7:00 AM Pasha Tatashin <pasha.tatashin@soleen.com> wrote:
>
> > Hi, Pasha
> >
> > In our previous discussion, we talked about counting the number of times
> > the kernel is rebooted via kexec. At that time, you suggested adding a
> > variable in debugfs to keep track of this count.
> > However, since debugfs is now optional, where would be an appropriate
> > place to store this variable?
>
> It is an optional config and can still be enabled if the live update
> reboot number value needs to be accessed through debugfs. However,
> given that debugfs does not guarantee a stable interface, tooling
> should not be built to require these interfaces.
>
> In the WIP LUO [1] I have, I pr_info() the live update number during
> boot and also store it in the incoming LUO FDT tree, which can also be
> accessed through this optional debugfs interface.
>
> The pr_info message appears like this during boot:
> [ 0.000000] luo: Retrieved live update data, liveupdate number: 17
>
> Pasha
Forgot to add link to WIP LUOv5:
[1] https://github.com/soleen/linux/tree/luo/v5rc04
next prev parent reply other threads:[~2025-11-07 12:03 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-01 14:23 [PATCH v9 0/9] liveupdate: Rework KHO for in-kernel users Pasha Tatashin
2025-11-01 14:23 ` [PATCH v9 1/9] kho: make debugfs interface optional Pasha Tatashin
2025-11-07 6:03 ` Zhu Yanjun
2025-11-07 12:00 ` Pasha Tatashin
2025-11-07 12:02 ` Pasha Tatashin [this message]
2025-11-07 23:35 ` Yanjun.Zhu
2025-11-08 18:13 ` Pasha Tatashin
2025-11-10 0:20 ` Zhu Yanjun
2025-11-10 13:16 ` Pratyush Yadav
2025-11-10 15:26 ` Pasha Tatashin
2025-11-11 4:11 ` Zhu Yanjun
2025-11-11 15:26 ` Pasha Tatashin
2025-11-13 1:41 ` Yanjun.Zhu
2025-11-13 2:11 ` Yanjun.Zhu
2025-11-13 19:59 ` Pasha Tatashin
2025-11-13 20:07 ` Yanjun.Zhu
2025-11-13 19:55 ` Yanjun.Zhu
2025-11-13 20:10 ` Pasha Tatashin
2025-11-13 20:13 ` Pasha Tatashin
2025-11-13 20:28 ` Yanjun.Zhu
2025-11-01 14:23 ` [PATCH v9 2/9] kho: drop notifiers Pasha Tatashin
2025-11-06 8:41 ` kernel test robot
2025-11-06 21:46 ` Pasha Tatashin
2025-11-06 22:14 ` Pasha Tatashin
2025-11-01 14:23 ` [PATCH v9 3/9] kho: add interfaces to unpreserve folios, page ranges, and vmalloc Pasha Tatashin
2025-11-03 18:05 ` Pratyush Yadav
2025-11-01 14:23 ` [PATCH v9 4/9] memblock: Unpreserve memory in case of error Pasha Tatashin
2025-11-02 6:51 ` Mike Rapoport
2025-11-05 10:26 ` Pratyush Yadav
2025-11-01 14:23 ` [PATCH v9 5/9] test_kho: " Pasha Tatashin
2025-11-01 14:23 ` [PATCH v9 6/9] kho: don't unpreserve memory during abort Pasha Tatashin
2025-11-05 10:28 ` Pratyush Yadav
2025-11-01 14:23 ` [PATCH v9 7/9] liveupdate: kho: move to kernel/liveupdate Pasha Tatashin
2025-11-06 7:21 ` kernel test robot
2025-11-07 22:23 ` Andrew Morton
2025-11-08 18:01 ` Pasha Tatashin
2025-11-01 14:23 ` [PATCH v9 8/9] MAINTAINERS: update KHO maintainers Pasha Tatashin
2025-11-01 16:36 ` Mike Rapoport
2025-11-01 14:23 ` [PATCH v9 9/9] liveupdate: kho: Use %pe format specifier for error pointer printing Pasha Tatashin
2025-11-01 19:45 ` Zhu Yanjun
2025-11-02 6:59 ` Mike Rapoport
2025-11-03 12:59 ` Pratyush Yadav
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