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From: Juri Lelli <juri.lelli@redhat.com>
To: Waiman Long <longman@redhat.com>
Cc: Tejun Heo <tj@kernel.org>, Li Zefan <lizefan@huawei.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-doc@vger.kernel.org, kernel-team@fb.com, pjt@google.com,
	luto@amacapital.net, Mike Galbraith <efault@gmx.de>,
	torvalds@linux-foundation.org, Roman Gushchin <guro@fb.com>,
	Patrick Bellasi <patrick.bellasi@arm.com>
Subject: Re: [PATCH] cpuset: Enforce that a child's cpus must be a subset of the parent
Date: Wed, 30 May 2018 16:00:21 +0200	[thread overview]
Message-ID: <20180530140021.GF3320@localhost.localdomain> (raw)
In-Reply-To: <1527687991-1431-1-git-send-email-longman@redhat.com>

Hi,

On 30/05/18 09:46, Waiman Long wrote:
> It was found that the cpuset.cpus could contain CPUs that are not listed
> in their parent's cpu list as shown by the command sequence below:
> 
>   # echo "+cpuset" >cgroup.subtree_control
>   # mkdir g1
>   # echo 0-5 >g1/cpuset.cpus
>   # mkdir g1/g11
>   # echo "+cpuset" > g1/cgroup.subtree_control
>   # echo 6-11 >g1/g11/cpuset.cpus
>   # grep -R . g1 | grep "\.cpus"
>   g1/cpuset.cpus:0-5
>   g1/cpuset.cpus.effective:0-5
>   g1/g11/cpuset.cpus:6-11
>   g1/g11/cpuset.cpus.effective:0-5
> 
> As the intersection of g11's cpus and that of g1 is empty, the effective
> cpus of g11 is just that of g1. The check in update_cpumask() is now
> corrected to make sure that cpus in a child cpus must be a subset of
> its parent's cpus. The error "write error: Invalid argument" will now
> be reported in the above case.
> 
> Reported-by: Juri Lelli <juri.lelli@redhat.com>
> Signed-off-by: Waiman Long <longman@redhat.com>

Looks like it fixes the bug.

Reviewed-and-Tested-by: Juri Lelli <juri.lelli@redhat.com>

Thanks,

- Juri

WARNING: multiple messages have this Message-ID (diff)
From: Juri Lelli <juri.lelli@redhat.com>
To: Waiman Long <longman@redhat.com>
Cc: Tejun Heo <tj@kernel.org>, Li Zefan <lizefan@huawei.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-doc@vger.kernel.org, kernel-team@fb.com, pjt@google.com,
	luto@amacapital.net, Mike Galbraith <efault@gmx.de>,
	torvalds@linux-foundation.org, Roman Gushchin <guro@fb.com>,
	Patrick Bellasi <patrick.bellasi@arm.com>
Subject: Re: [PATCH] cpuset: Enforce that a child's cpus must be a subset of the parent
Date: Wed, 30 May 2018 16:00:21 +0200	[thread overview]
Message-ID: <20180530140021.GF3320@localhost.localdomain> (raw)
In-Reply-To: <1527687991-1431-1-git-send-email-longman@redhat.com>

Hi,

On 30/05/18 09:46, Waiman Long wrote:
> It was found that the cpuset.cpus could contain CPUs that are not listed
> in their parent's cpu list as shown by the command sequence below:
> 
>   # echo "+cpuset" >cgroup.subtree_control
>   # mkdir g1
>   # echo 0-5 >g1/cpuset.cpus
>   # mkdir g1/g11
>   # echo "+cpuset" > g1/cgroup.subtree_control
>   # echo 6-11 >g1/g11/cpuset.cpus
>   # grep -R . g1 | grep "\.cpus"
>   g1/cpuset.cpus:0-5
>   g1/cpuset.cpus.effective:0-5
>   g1/g11/cpuset.cpus:6-11
>   g1/g11/cpuset.cpus.effective:0-5
> 
> As the intersection of g11's cpus and that of g1 is empty, the effective
> cpus of g11 is just that of g1. The check in update_cpumask() is now
> corrected to make sure that cpus in a child cpus must be a subset of
> its parent's cpus. The error "write error: Invalid argument" will now
> be reported in the above case.
> 
> Reported-by: Juri Lelli <juri.lelli@redhat.com>
> Signed-off-by: Waiman Long <longman@redhat.com>

Looks like it fixes the bug.

Reviewed-and-Tested-by: Juri Lelli <juri.lelli@redhat.com>

Thanks,

- Juri
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  reply	other threads:[~2018-05-30 14:00 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-30 13:46 [PATCH] cpuset: Enforce that a child's cpus must be a subset of the parent Waiman Long
2018-05-30 13:46 ` Waiman Long
2018-05-30 14:00 ` Juri Lelli [this message]
2018-05-30 14:00   ` Juri Lelli
2018-05-31  1:25 ` Zefan Li
2018-05-31  1:25   ` Zefan Li
2018-05-31  1:25   ` Zefan Li
2018-05-31  7:43   ` Peter Zijlstra
2018-05-31  7:43     ` Peter Zijlstra
2018-05-31  8:12   ` Zefan Li
2018-05-31  8:12     ` Zefan Li
2018-05-31  8:12     ` Zefan Li
2018-05-31  8:26     ` Peter Zijlstra
2018-05-31  8:26       ` Peter Zijlstra
2018-05-31  8:41       ` Juri Lelli
2018-05-31  8:41         ` Juri Lelli
2018-05-31  8:42       ` Zefan Li
2018-05-31  8:42         ` Zefan Li
2018-05-31  8:42         ` Zefan Li
2018-05-31 13:22         ` Waiman Long
2018-05-31 13:22           ` Waiman Long
2018-05-31 15:58           ` Tejun Heo
2018-05-31 15:58             ` Tejun Heo
2018-05-31 16:16             ` Peter Zijlstra
2018-05-31 16:16               ` Peter Zijlstra
2018-05-31 16:19               ` Tejun Heo
2018-05-31 16:19                 ` Tejun Heo
2018-05-31 16:38                 ` Peter Zijlstra
2018-05-31 16:38                   ` Peter Zijlstra
2018-06-06 20:56                   ` Tejun Heo
2018-06-06 20:56                     ` Tejun Heo
2018-05-31 16:28             ` Waiman Long
2018-05-31 16:28               ` Waiman Long

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