[PATCH] workqueue: Add the allocation flags to function schedule_on_each_cpu_gfp

[Minfei Huang <mnfhuang@gmail.com>]

Rename the function schedule_on_each_cpu to schedule_on_each_cpu_gfp to
add the allocation flags as parameter.

In several situation in ftrace, we are nervous and never come back, once
schedule_on_each_cpu fails to alloc the percpu work. Add the allocation
flags __GFP_NOFAIL to guarantee it.

Signed-off-by: Minfei Huang <mnfhuang@gmail.com>
---
 arch/x86/platform/uv/uv_time.c |  2 +-
 include/linux/ftrace.h         |  2 +-
 include/linux/workqueue.h      |  2 +-
 kernel/trace/ftrace.c          |  5 +++--
 kernel/trace/trace_events.c    |  2 +-
 kernel/workqueue.c             | 11 ++++++-----
 6 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/arch/x86/platform/uv/uv_time.c b/arch/x86/platform/uv/uv_time.c
index a244237..a87a16a 100644
--- a/arch/x86/platform/uv/uv_time.c
+++ b/arch/x86/platform/uv/uv_time.c
@@ -405,7 +405,7 @@ static __init int uv_rtc_setup_clock(void)
 	clock_event_device_uv.max_delta_ns = clocksource_uv.mask *
 				(NSEC_PER_SEC / sn_rtc_cycles_per_second);
 
-	rc = schedule_on_each_cpu(uv_rtc_register_clockevents);
+	rc = schedule_on_each_cpu_gfp(uv_rtc_register_clockevents, GFP_KERNEL);
 	if (rc) {
 		x86_platform_ipi_callback = NULL;
 		uv_rtc_deallocate_timers();
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 6cd8c0e..d6d3cf5 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -154,7 +154,7 @@ struct ftrace_ops_hash {
  *
  * Any private data added must also take care not to be freed and if private
  * data is added to a ftrace_ops that is in core code, the user of the
- * ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
+ * ftrace_ops must perform a schedule_on_each_cpu_gfp() before freeing it.
  */
 struct ftrace_ops {
 	ftrace_func_t			func;
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 738b30b..2de50fe 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -436,7 +436,7 @@ extern bool mod_delayed_work_on(int cpu, struct workqueue_struct *wq,
 extern void flush_workqueue(struct workqueue_struct *wq);
 extern void drain_workqueue(struct workqueue_struct *wq);
 
-extern int schedule_on_each_cpu(work_func_t func);
+extern int schedule_on_each_cpu_gfp(work_func_t func, gfp_t gfp);
 
 int execute_in_process_context(work_func_t fn, struct execute_work *);
 
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index eb11011..f8d3111 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -324,7 +324,7 @@ static void update_ftrace_function(void)
 	 * Make sure all CPUs see this. Yes this is slow, but static
 	 * tracing is slow and nasty to have enabled.
 	 */
-	schedule_on_each_cpu(ftrace_sync);
+	schedule_on_each_cpu_gfp(ftrace_sync, GFP_KERNEL | __GFP_NOFAIL);
 	/* Now all cpus are using the list ops. */
 	function_trace_op = set_function_trace_op;
 	/* Make sure the function_trace_op is visible on all CPUs */
@@ -2716,7 +2716,8 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command)
 	 * ourselves.
 	 */
 	if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_CONTROL)) {
-		schedule_on_each_cpu(ftrace_sync);
+		schedule_on_each_cpu_gfp(ftrace_sync,
+				GFP_KERNEL | __GFP_NOFAIL);
 
 		arch_ftrace_trampoline_free(ops);
 
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 404a372..6cf0dba 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -2722,7 +2722,7 @@ static __init int event_test_thread(void *unused)
 	if (!test_malloc)
 		pr_info("failed to kmalloc\n");
 
-	schedule_on_each_cpu(test_work);
+	schedule_on_each_cpu_gfp(test_work, GFP_KERNEL);
 
 	kfree(test_malloc);
 
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 4c4f061..f7ef6bb 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2917,22 +2917,23 @@ bool cancel_delayed_work_sync(struct delayed_work *dwork)
 EXPORT_SYMBOL(cancel_delayed_work_sync);
 
 /**
- * schedule_on_each_cpu - execute a function synchronously on each online CPU
+ * schedule_on_each_cpu_gfp - execute function synchronously on each online CPU
  * @func: the function to call
+ * @gfp: allocation flags
  *
- * schedule_on_each_cpu() executes @func on each online CPU using the
+ * schedule_on_each_cpu_gfp() executes @func on each online CPU using the
  * system workqueue and blocks until all CPUs have completed.
- * schedule_on_each_cpu() is very slow.
+ * schedule_on_each_cpu_gfp() is very slow.
  *
  * Return:
  * 0 on success, -errno on failure.
  */
-int schedule_on_each_cpu(work_func_t func)
+int schedule_on_each_cpu_gfp(work_func_t func, gfp_t gfp)
 {
 	int cpu;
 	struct work_struct __percpu *works;
 
-	works = alloc_percpu(struct work_struct);
+	works = alloc_percpu_gfp(struct work_struct, gfp);
 	if (!works)
 		return -ENOMEM;
 
-- 
2.4.0