Re: [PATCH] cgroup: use assign_bit() where applicable

[Michal Koutný]

On Sun, Sep 20, 2026 at 10:27:37AM +0800, "Peng Fan (OSS)" <peng.fan@xxxxxxxxxxx> wrote:
> From: Peng Fan <peng.fan@xxxxxxx>
> 
> Convert open-coded if/else with set_bit/clear_bit and their
> non-atomic __set_bit/__clear_bit variants to the assign_bit/__assign_bit
> API.
> 
> Done with Coccinelle semantic patch:
>     // set_bit -> clear_bit => assign_bit
> 
>     @@
>     expression cond, bit, addr;
>     @@
> 
>     -if (cond)
>     -        set_bit(bit, addr);
>     -else
>     -        clear_bit(bit, addr);
>     +assign_bit(bit, addr, cond);
> 
>     // clear_bit -> set_bit => assign_bit
> 
>     @@
>     expression cond, bit, addr;
>     @@
> 
>     -if (cond)
>     -        clear_bit(bit, addr);
>     -else
>     -        set_bit(bit, addr);
>     +assign_bit(bit, addr, !cond);
> 
>     // __set_bit -> __clear_bit => __assign_bit
> 
>     @@
>     expression cond, bit, addr;
>     @@
> 
>     -if (cond)
>     -        __set_bit(bit, addr);
>     -else
>     -        __clear_bit(bit, addr);
>     +__assign_bit(bit, addr, cond);
> 
>     // __clear_bit -> __set_bit => __assign_bit
> 
>     @@
>     expression cond, bit, addr;
>     @@
> 
>     -if (cond)
>     -        __clear_bit(bit, addr);
>     -else
>     -        __set_bit(bit, addr);
>     +__assign_bit(bit, addr, !cond);
> 
> Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> ---
>  kernel/cgroup/cgroup-v1.c | 10 ++--------
>  kernel/cgroup/cpuset.c    | 16 ++++------------
>  kernel/cgroup/freezer.c   |  5 +----
>  3 files changed, 7 insertions(+), 24 deletions(-)

Nice use of Coccinelle,
Acked-by: Michal Koutný <mkoutny@xxxxxxxx>

(You may consider sharing an adjusted variant for
scripts/coccinelle/misc/ via cocci@xxxxxxxx ML.)