* [PATCH-cgroup] cgroup/cpuset: Fix incorrect top_cpuset flags
@ 2024-04-24 1:00 Waiman Long
2024-04-24 1:02 ` Waiman Long
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Waiman Long @ 2024-04-24 1:00 UTC (permalink / raw)
To: Tejun Heo, Zefan Li, Johannes Weiner
Cc: linux-kernel, cgroups, Xiu Jianfeng, Waiman Long
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),
--
2.39.3
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH-cgroup] cgroup/cpuset: Fix incorrect top_cpuset flags
2024-04-24 1:00 [PATCH-cgroup] cgroup/cpuset: Fix incorrect top_cpuset flags Waiman Long
@ 2024-04-24 1:02 ` Waiman Long
2024-04-24 1:30 ` xiujianfeng
2024-04-24 3:32 ` Tejun Heo
2024-04-24 11:12 ` Klara Modin
2 siblings, 1 reply; 5+ messages in thread
From: Waiman Long @ 2024-04-24 1:02 UTC (permalink / raw)
To: Tejun Heo, Zefan Li, Johannes Weiner
Cc: linux-kernel, cgroups, Xiu Jianfeng, Xiu Jianfeng
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>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH-cgroup] cgroup/cpuset: Fix incorrect top_cpuset flags
2024-04-24 1:02 ` Waiman Long
@ 2024-04-24 1:30 ` xiujianfeng
0 siblings, 0 replies; 5+ messages in thread
From: xiujianfeng @ 2024-04-24 1:30 UTC (permalink / raw)
To: Waiman Long, Tejun Heo, Zefan Li, Johannes Weiner; +Cc: linux-kernel, cgroups
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. :)
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH-cgroup] cgroup/cpuset: Fix incorrect top_cpuset flags
2024-04-24 1:00 [PATCH-cgroup] cgroup/cpuset: Fix incorrect top_cpuset flags Waiman Long
2024-04-24 1:02 ` Waiman Long
@ 2024-04-24 3:32 ` Tejun Heo
2024-04-24 11:12 ` Klara Modin
2 siblings, 0 replies; 5+ messages in thread
From: Tejun Heo @ 2024-04-24 3:32 UTC (permalink / raw)
To: Waiman Long
Cc: Zefan Li, Johannes Weiner, linux-kernel, cgroups, Xiu Jianfeng
On Tue, Apr 23, 2024 at 09:00:20PM -0400, 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>
Applied to cgroup/for-6.10.
Thanks.
--
tejun
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH-cgroup] cgroup/cpuset: Fix incorrect top_cpuset flags
2024-04-24 1:00 [PATCH-cgroup] cgroup/cpuset: Fix incorrect top_cpuset flags Waiman Long
2024-04-24 1:02 ` Waiman Long
2024-04-24 3:32 ` Tejun Heo
@ 2024-04-24 11:12 ` Klara Modin
2 siblings, 0 replies; 5+ messages in thread
From: Klara Modin @ 2024-04-24 11:12 UTC (permalink / raw)
To: Waiman Long, Tejun Heo, Zefan Li, Johannes Weiner
Cc: linux-kernel, cgroups, Xiu Jianfeng
On 2024-04-24 03:00, 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),
I saw this made its way into today's next and can confirm it fixes the
issue I reported in [1].
Thanks,
Tested-by: Klara Modin <klarasmodin@gmail.com>
1.
https://lore.kernel.org/lkml/f2edf788-6ff3-43b1-9445-ac237e7910ac@gmail.com
^ permalink raw reply [flat|nested] 5+ messages in thread
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2024-04-24 1:00 [PATCH-cgroup] cgroup/cpuset: Fix incorrect top_cpuset flags Waiman Long
2024-04-24 1:02 ` Waiman Long
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2024-04-24 3:32 ` Tejun Heo
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