Re: [PATCH v3 1/8] user_namespace: Use acquire/release for nr_extents synchronization

[Jinjie Ruan]

在 2026/9/2 21:03, Andy Shevchenko 写道:
> On Wed, Sep 02, 2026 at 03:47:58PM +0800, Jinjie Ruan wrote:
>> Replace smp_wmb()/smp_rmb() with smp_store_release()/smp_load_acquire()
>> when publishing and consuming `nr_extents`. This expresses the
>> publish/subscribe pattern more clearly and allows architectures with
>> native acquire/release instructions (e.g. arm64's STLR/LDAR) to avoid
>> the cost of full one-way barriers (DMB ISHST/ISHLD).
>>
>> No functional change intended.
> 
> Please, locate Cc list...
> 
>> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
>> Cc: Christian Brauner <brauner@xxxxxxxxxx>
>> Cc: Jan Kara <jack@xxxxxxx>
>> Cc: Seth Forshee <sforshee@xxxxxxxxxx>
>> Cc: Kees Cook <kees@xxxxxxxxxx>
>> Cc: Aleksa Sarai <cyphar@xxxxxxxxxx>o
> 
> ...(all the above)...
> 
>> Assisted-by: DeepSeek:DeepSeek-V3
>> Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
>> ---
> 
> ...somewhere here. It will have the same effect on the email thread and it will
> unload the commit message from the unneeded noise.

Many thanks for your kind reminder.

> 
>> v2:
>> - Add missing load replace in copy_mnt_idmap()
>> ---
>>  fs/mnt_idmapping.c      |  5 ++---
>>  kernel/user_namespace.c | 24 +++++++++++++-----------
>>  2 files changed, 15 insertions(+), 14 deletions(-)
> 
> ...
> 
> This comment applies to the whole series.
> Also note, `b4 trailers` can handle that, you can keep the

Previously, I added Cc and review tags manually. I'll take some time to
learn how to use b4 trailers to manage the format properly.

> 
>   ---
>   Cc: ...
> 
> in the local Git. You can find some details in the subthread here
> https://lore.kernel.org/lkml/20260123113708.416727-19-bigeasy@xxxxxxxxxxxxx/
>