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| author | Miao Xie <miaox@cn.fujitsu.com> | 2010-03-23 13:35:34 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-04-01 15:58:46 -0700 |
| commit | 893b328f07c17aa84f562fc5566eb524bd76188e (patch) | |
| tree | 6ee34077dea0834d5952d8696c60bd9543747553 /kernel | |
| parent | fa8e8558a6874707d8e30c85bb386f43cb61a6e1 (diff) | |
| download | lwn-893b328f07c17aa84f562fc5566eb524bd76188e.tar.gz lwn-893b328f07c17aa84f562fc5566eb524bd76188e.zip | |
cpuset: fix the problem that cpuset_mem_spread_node() returns an offline node
commit 5ab116c9349ef52d6fbd2e2917a53f13194b048e upstream.
cpuset_mem_spread_node() returns an offline node, and causes an oops.
This patch fixes it by initializing task->mems_allowed to
node_states[N_HIGH_MEMORY], and updating task->mems_allowed when doing
memory hotplug.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Reported-by: Nick Piggin <npiggin@suse.de>
Tested-by: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cpuset.c | 20 | ||||
| -rw-r--r-- | kernel/kthread.c | 2 |
2 files changed, 13 insertions, 9 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 39e5121a78a6..a81a91010c9f 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -921,9 +921,6 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs, * call to guarantee_online_mems(), as we know no one is changing * our task's cpuset. * - * Hold callback_mutex around the two modifications of our tasks - * mems_allowed to synchronize with cpuset_mems_allowed(). - * * While the mm_struct we are migrating is typically from some * other task, the task_struct mems_allowed that we are hacking * is for our current task, which must allocate new pages for that @@ -1392,11 +1389,10 @@ static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cont, if (cs == &top_cpuset) { cpumask_copy(cpus_attach, cpu_possible_mask); - to = node_possible_map; } else { guarantee_online_cpus(cs, cpus_attach); - guarantee_online_mems(cs, &to); } + guarantee_online_mems(cs, &to); /* do per-task migration stuff possibly for each in the threadgroup */ cpuset_attach_task(tsk, &to, cs); @@ -2091,15 +2087,23 @@ static int cpuset_track_online_cpus(struct notifier_block *unused_nb, static int cpuset_track_online_nodes(struct notifier_block *self, unsigned long action, void *arg) { + nodemask_t oldmems; + cgroup_lock(); switch (action) { case MEM_ONLINE: - case MEM_OFFLINE: + oldmems = top_cpuset.mems_allowed; mutex_lock(&callback_mutex); top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY]; mutex_unlock(&callback_mutex); - if (action == MEM_OFFLINE) - scan_for_empty_cpusets(&top_cpuset); + update_tasks_nodemask(&top_cpuset, &oldmems, NULL); + break; + case MEM_OFFLINE: + /* + * needn't update top_cpuset.mems_allowed explicitly because + * scan_for_empty_cpusets() will update it. + */ + scan_for_empty_cpusets(&top_cpuset); break; default: break; diff --git a/kernel/kthread.c b/kernel/kthread.c index ab7ae57773e1..84027cfffccf 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -196,7 +196,7 @@ int kthreadd(void *unused) set_task_comm(tsk, "kthreadd"); ignore_signals(tsk); set_cpus_allowed_ptr(tsk, cpu_all_mask); - set_mems_allowed(node_possible_map); + set_mems_allowed(node_states[N_HIGH_MEMORY]); current->flags |= PF_NOFREEZE | PF_FREEZER_NOSIG; |