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authorDavid Rientjes <rientjes@google.com>2009-01-06 14:39:01 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-06 15:58:59 -0800
commit75aa199410359dc5fbcf9025ff7af98a9d20f0d5 (patch)
tree569bffa181ccba56d884ec7e826ae61384297f56
parentc7d4caeb1d68d07f77cc09fc20b7759d6d7aa3b1 (diff)
oom: print triggering task's cpuset and mems allowed
When cpusets are enabled, it's necessary to print the triggering task's set of allowable nodes so the subsequently printed meminfo can be interpreted correctly. We also print the task's cpuset name for informational purposes. [rientjes@google.com: task lock current before dereferencing cpuset] Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/cpuset.h6
-rw-r--r--kernel/cpuset.c34
-rw-r--r--mm/oom_kill.c3
3 files changed, 43 insertions, 0 deletions
diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h
index 8e540d32c9f..51ea2bdea0f 100644
--- a/include/linux/cpuset.h
+++ b/include/linux/cpuset.h
@@ -78,6 +78,8 @@ extern int current_cpuset_is_being_rebound(void);
extern void rebuild_sched_domains(void);
+extern void cpuset_print_task_mems_allowed(struct task_struct *p);
+
#else /* !CONFIG_CPUSETS */
static inline int cpuset_init_early(void) { return 0; }
@@ -159,6 +161,10 @@ static inline void rebuild_sched_domains(void)
partition_sched_domains(1, NULL, NULL);
}
+static inline void cpuset_print_task_mems_allowed(struct task_struct *p)
+{
+}
+
#endif /* !CONFIG_CPUSETS */
#endif /* _LINUX_CPUSET_H */
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 39c1a4c1c5a..345ace5117d 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -240,6 +240,17 @@ static struct cpuset top_cpuset = {
static DEFINE_MUTEX(callback_mutex);
/*
+ * cpuset_buffer_lock protects both the cpuset_name and cpuset_nodelist
+ * buffers. They are statically allocated to prevent using excess stack
+ * when calling cpuset_print_task_mems_allowed().
+ */
+#define CPUSET_NAME_LEN (128)
+#define CPUSET_NODELIST_LEN (256)
+static char cpuset_name[CPUSET_NAME_LEN];
+static char cpuset_nodelist[CPUSET_NODELIST_LEN];
+static DEFINE_SPINLOCK(cpuset_buffer_lock);
+
+/*
* This is ugly, but preserves the userspace API for existing cpuset
* users. If someone tries to mount the "cpuset" filesystem, we
* silently switch it to mount "cgroup" instead
@@ -2356,6 +2367,29 @@ int cpuset_mems_allowed_intersects(const struct task_struct *tsk1,
return nodes_intersects(tsk1->mems_allowed, tsk2->mems_allowed);
}
+/**
+ * cpuset_print_task_mems_allowed - prints task's cpuset and mems_allowed
+ * @task: pointer to task_struct of some task.
+ *
+ * Description: Prints @task's name, cpuset name, and cached copy of its
+ * mems_allowed to the kernel log. Must hold task_lock(task) to allow
+ * dereferencing task_cs(task).
+ */
+void cpuset_print_task_mems_allowed(struct task_struct *tsk)
+{
+ struct dentry *dentry;
+
+ dentry = task_cs(tsk)->css.cgroup->dentry;
+ spin_lock(&cpuset_buffer_lock);
+ snprintf(cpuset_name, CPUSET_NAME_LEN,
+ dentry ? (const char *)dentry->d_name.name : "/");
+ nodelist_scnprintf(cpuset_nodelist, CPUSET_NODELIST_LEN,
+ tsk->mems_allowed);
+ printk(KERN_INFO "%s cpuset=%s mems_allowed=%s\n",
+ tsk->comm, cpuset_name, cpuset_nodelist);
+ spin_unlock(&cpuset_buffer_lock);
+}
+
/*
* Collection of memory_pressure is suppressed unless
* this flag is enabled by writing "1" to the special
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index e5f50cfdca4..6b9e758c98a 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -392,6 +392,9 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
printk(KERN_WARNING "%s invoked oom-killer: "
"gfp_mask=0x%x, order=%d, oomkilladj=%d\n",
current->comm, gfp_mask, order, current->oomkilladj);
+ task_lock(current);
+ cpuset_print_task_mems_allowed(current);
+ task_unlock(current);
dump_stack();
show_mem();
if (sysctl_oom_dump_tasks)