Re: [PATCH-cgroup] cgroup/cpuset: Fix incorrect top_cpuset flags
From: xiujianfeng
Date: Tue Apr 23 2024 - 21:30:40 EST
On 2024/4/24 9:02, Waiman Long wrote:
>
> On 4/23/24 21:00, Waiman Long wrote:
>> Commit 8996f93fc388 ("cgroup/cpuset: Statically initialize more
>> members of top_cpuset") uses an incorrect "<" relational operator for
>> the CS_SCHED_LOAD_BALANCE bit when initializing the top_cpuset. This
>> results in load_balancing turned off by default in the top cpuset which
>> is bad for performance.
>>
>> Fix this by using the BIT() helper macro to set the desired top_cpuset
>> flags and avoid similar mistake from being made in the future.
>>
>> Fixes: 8996f93fc388 ("cgroup/cpuset: Statically initialize more
>> members of top_cpuset")
>> Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
>> ---
>> kernel/cgroup/cpuset.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
>> index e70008a1d86a..b0a97efa5f20 100644
>> --- a/kernel/cgroup/cpuset.c
>> +++ b/kernel/cgroup/cpuset.c
>> @@ -368,8 +368,8 @@ static inline void notify_partition_change(struct
>> cpuset *cs, int old_prs)
>> }
>> static struct cpuset top_cpuset = {
>> - .flags = ((1 << CS_ONLINE) | (1 << CS_CPU_EXCLUSIVE) |
>> - (1 << CS_MEM_EXCLUSIVE) | (1 < CS_SCHED_LOAD_BALANCE)),
>> + .flags = BIT(CS_ONLINE) | BIT(CS_CPU_EXCLUSIVE) |
>> + BIT(CS_MEM_EXCLUSIVE) | BIT(CS_SCHED_LOAD_BALANCE),
>> .partition_root_state = PRS_ROOT,
>> .relax_domain_level = -1,
>> .remote_sibling = LIST_HEAD_INIT(top_cpuset.remote_sibling),
> Add cc to xiujianfeng <xiujianfeng@xxxxxxxxxx>
Thanks, this looks good. :)
>