* cpuset: Check if the cpus allowed is a subset of the cpuset's cpus for PF_THREAD_BOUND threads
@ 2009-03-12 17:45 Dhaval Giani
2009-03-13 0:06 ` [tip:sched/urgent] " Dhaval Giani
0 siblings, 1 reply; 4+ messages in thread
From: Dhaval Giani @ 2009-03-12 17:45 UTC (permalink / raw)
To: Srivatsa Vaddagiri, lkml, Andrew Morton, menage; +Cc: Balbir Singh
When a kernel thread which has been bound to a CPU is moved to
a cpuset which is a superset of the CPU it is bound to, the
movement fails.
[root@llm11 cgroups]# mkdir a
[root@llm11 cgroups]# echo 3 > a/cpuset.cpus
[root@llm11 cgroups]# echo 0 > a/cpuset.mems
[root@llm11 cgroups]# echo 12 > a/tasks
[root@llm11 cgroups]# echo 12 > tasks
-bash: echo: write error: Invalid argument
[root@llm11 cgroups]# cat cpuset.cpus
0-7
[root@llm11 cgroups]#
(pid 12 is the migration thread bound to CPU 3)
Change the check to see if the cpus allowed is a subset of the
cpus allowed for that cpuset.
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
---
kernel/cpuset.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1362,7 +1362,7 @@ static int cpuset_can_attach(struct cgro
if (tsk->flags & PF_THREAD_BOUND) {
mutex_lock(&callback_mutex);
- if (!cpumask_equal(&tsk->cpus_allowed, cs->cpus_allowed))
+ if (!cpumask_subset(&tsk->cpus_allowed, cs->cpus_allowed))
ret = -EINVAL;
mutex_unlock(&callback_mutex);
}
--
regards,
Dhaval
^ permalink raw reply [flat|nested] 4+ messages in thread* [tip:sched/urgent] cpuset: Check if the cpus allowed is a subset of the cpuset's cpus for PF_THREAD_BOUND threads
2009-03-12 17:45 cpuset: Check if the cpus allowed is a subset of the cpuset's cpus for PF_THREAD_BOUND threads Dhaval Giani
@ 2009-03-13 0:06 ` Dhaval Giani
2009-03-13 1:32 ` Ingo Molnar
0 siblings, 1 reply; 4+ messages in thread
From: Dhaval Giani @ 2009-03-13 0:06 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, vatsa, hpa, mingo, dhaval, balbir, akpm, tglx, mingo
Commit-ID: 5a98d36112f4301f068b638d6e0db2357f7deb75
Gitweb: http://git.kernel.org/tip/5a98d36112f4301f068b638d6e0db2357f7deb75
Author: Dhaval Giani <dhaval@linux.vnet.ibm.com>
AuthorDate: Thu, 12 Mar 2009 23:15:01 +0530
Commit: Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 13 Mar 2009 00:21:25 +0100
cpuset: Check if the cpus allowed is a subset of the cpuset's cpus for PF_THREAD_BOUND threads
When a kernel thread which has been bound to a CPU is moved to
a cpuset which is a superset of the CPU it is bound to, the
movement fails.
[root@llm11 cgroups]# mkdir a
[root@llm11 cgroups]# echo 3 > a/cpuset.cpus
[root@llm11 cgroups]# echo 0 > a/cpuset.mems
[root@llm11 cgroups]# echo 12 > a/tasks
[root@llm11 cgroups]# echo 12 > tasks
-bash: echo: write error: Invalid argument
[root@llm11 cgroups]# cat cpuset.cpus
0-7
[root@llm11 cgroups]#
(pid 12 is the migration thread bound to CPU 3)
Change the check to see if the cpus allowed is a subset of the
cpus allowed for that cpuset.
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: menage@google.com
LKML-Reference: <20090312174501.GA7821@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/cpuset.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index f76db9d..34cfd46 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1362,7 +1362,7 @@ static int cpuset_can_attach(struct cgroup_subsys *ss,
if (tsk->flags & PF_THREAD_BOUND) {
mutex_lock(&callback_mutex);
- if (!cpumask_equal(&tsk->cpus_allowed, cs->cpus_allowed))
+ if (!cpumask_subset(&tsk->cpus_allowed, cs->cpus_allowed))
ret = -EINVAL;
mutex_unlock(&callback_mutex);
}
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [tip:sched/urgent] cpuset: Check if the cpus allowed is a subset of the cpuset's cpus for PF_THREAD_BOUND threads
2009-03-13 0:06 ` [tip:sched/urgent] " Dhaval Giani
@ 2009-03-13 1:32 ` Ingo Molnar
2009-03-13 1:43 ` Li Zefan
0 siblings, 1 reply; 4+ messages in thread
From: Ingo Molnar @ 2009-03-13 1:32 UTC (permalink / raw)
To: mingo, hpa, vatsa, linux-kernel, dhaval, balbir, akpm, tglx
Cc: linux-tip-commits
* Dhaval Giani <dhaval@linux.vnet.ibm.com> wrote:
> Commit-ID: 5a98d36112f4301f068b638d6e0db2357f7deb75
> Gitweb: http://git.kernel.org/tip/5a98d36112f4301f068b638d6e0db2357f7deb75
> Author: Dhaval Giani <dhaval@linux.vnet.ibm.com>
> AuthorDate: Thu, 12 Mar 2009 23:15:01 +0530
> Commit: Ingo Molnar <mingo@elte.hu>
> CommitDate: Fri, 13 Mar 2009 00:21:25 +0100
>
> cpuset: Check if the cpus allowed is a subset of the cpuset's
> cpus for PF_THREAD_BOUND threads
Dropped this patch for now - Andrew says it got NAK-ed and he's
handling it with other fixes.
Ingo
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [tip:sched/urgent] cpuset: Check if the cpus allowed is a subset of the cpuset's cpus for PF_THREAD_BOUND threads
2009-03-13 1:32 ` Ingo Molnar
@ 2009-03-13 1:43 ` Li Zefan
0 siblings, 0 replies; 4+ messages in thread
From: Li Zefan @ 2009-03-13 1:43 UTC (permalink / raw)
To: Ingo Molnar
Cc: mingo, hpa, vatsa, linux-kernel, dhaval, balbir, akpm, tglx,
linux-tip-commits
CC: David Rientjes <rientjes@google.com>
Ingo Molnar wrote:
> * Dhaval Giani <dhaval@linux.vnet.ibm.com> wrote:
>
>> Commit-ID: 5a98d36112f4301f068b638d6e0db2357f7deb75
>> Gitweb: http://git.kernel.org/tip/5a98d36112f4301f068b638d6e0db2357f7deb75
>> Author: Dhaval Giani <dhaval@linux.vnet.ibm.com>
>> AuthorDate: Thu, 12 Mar 2009 23:15:01 +0530
>> Commit: Ingo Molnar <mingo@elte.hu>
>> CommitDate: Fri, 13 Mar 2009 00:21:25 +0100
>>
>> cpuset: Check if the cpus allowed is a subset of the cpuset's
>> cpus for PF_THREAD_BOUND threads
>
> Dropped this patch for now - Andrew says it got NAK-ed and he's
> handling it with other fixes.
>
It's not a bug, it's David Rientjes that introduced this behavior:
9985b0bab332289f14837eff3c6e0bcc658b58f7
And here was the discussion:
http://lkml.org/lkml/2008/6/5/310
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2009-03-13 1:43 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2009-03-12 17:45 cpuset: Check if the cpus allowed is a subset of the cpuset's cpus for PF_THREAD_BOUND threads Dhaval Giani
2009-03-13 0:06 ` [tip:sched/urgent] " Dhaval Giani
2009-03-13 1:32 ` Ingo Molnar
2009-03-13 1:43 ` Li Zefan
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