+ cpuset-check-if-the-cpus-allowed-is-a-subset-of-the-cpusets-cpus-for-pf_thread_bound-threads.patch added to -mm tree

* + cpuset-check-if-the-cpus-allowed-is-a-subset-of-the-cpusets-cpus-for-pf_thread_bound-threads.patch added to -mm tree
@ 2009-03-12 22:51 akpm
       [not found] ` <alpine.DEB.2.00.0903121619540.19505@chino.kir.corp.google.com>
  0 siblings, 1 reply; 3+ messages in thread
From: akpm @ 2009-03-12 22:51 UTC (permalink / raw)
  To: mm-commits; +Cc: dhaval, balbir, menage, rientjes, vatsa


The patch titled
     cpuset: check if the cpus allowed is a subset of the cpuset's cpus for PF_THREAD_BOUND threads
has been added to the -mm tree.  Its filename is
     cpuset-check-if-the-cpus-allowed-is-a-subset-of-the-cpusets-cpus-for-pf_thread_bound-threads.patch

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------------------------------------------------------
Subject: cpuset: check if the cpus allowed is a subset of the cpuset's cpus for PF_THREAD_BOUND threads
From: Dhaval Giani <dhaval@linux.vnet.ibm.com>

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>
Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/cpuset.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN kernel/cpuset.c~cpuset-check-if-the-cpus-allowed-is-a-subset-of-the-cpusets-cpus-for-pf_thread_bound-threads kernel/cpuset.c

--- a/kernel/cpuset.c~cpuset-check-if-the-cpus-allowed-is-a-subset-of-the-cpusets-cpus-for-pf_thread_bound-threads
+++ a/kernel/cpuset.c
@@ -1349,7 +1349,7 @@ 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);
 	}
_

Patches currently in -mm which might be from dhaval@linux.vnet.ibm.com are

origin.patch
cgroup-css-id-support-remove-rcu_read_lock-from-css_get_next.patch
cpuset-check-if-the-cpus-allowed-is-a-subset-of-the-cpusets-cpus-for-pf_thread_bound-threads.patch


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