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Date: Wed, 24 Apr 2024 09:30:21 +0800
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Subject: Re: [PATCH-cgroup] cgroup/cpuset: Fix incorrect top_cpuset flags
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To: Waiman Long <longman@redhat.com>, Tejun Heo <tj@kernel.org>, Zefan Li
	<lizefan.x@bytedance.com>, Johannes Weiner <hannes@cmpxchg.org>
CC: <linux-kernel@vger.kernel.org>, <cgroups@vger.kernel.org>
References: <20240424010020.181305-1-longman@redhat.com>
 <5c5089de-311c-4563-b534-2340e328a5ee@redhat.com>
From: xiujianfeng <xiujianfeng@huawei.com>
In-Reply-To: <5c5089de-311c-4563-b534-2340e328a5ee@redhat.com>
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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@redhat.com>
>> ---
>>   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@huawei.com>

Thanks, this looks good. :)

>