[PATCH] oprofile: hotplug cpu fixThis patch addresses problems when hotplugging cpus while profiling.Instead of allocating only online cpus, all possible cpu buffers areallocated, which allows cpus to be onlined during operation. If a cpu isofflined before profiling is shutdown wq_sync_buffer checks for thiscondition then cancels this work and does not sync this buffer.

[Chris J Arges]

---
 drivers/oprofile/cpu_buffer.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index e1bd5a9..8bb030b 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -39,7 +39,7 @@ void free_cpu_buffers(void)
 {
 	int i;
  
-	for_each_online_cpu(i) {
+	for_each_possible_cpu(i) {
 		vfree(per_cpu(cpu_buffer, i).buffer);
 		per_cpu(cpu_buffer, i).buffer = NULL;
 	}
@@ -51,7 +51,7 @@ int alloc_cpu_buffers(void)
  
 	unsigned long buffer_size = fs_cpu_buffer_size;
  
-	for_each_online_cpu(i) {
+	for_each_possible_cpu(i) {
 		struct oprofile_cpu_buffer *b = &per_cpu(cpu_buffer, i);
  
 		b->buffer = vmalloc_node(sizeof(struct op_sample) * buffer_size,
@@ -368,6 +368,11 @@ static void wq_sync_buffer(struct work_struct *work)
 	if (b->cpu != smp_processor_id()) {
 		printk(KERN_DEBUG "WQ on CPU%d, prefer CPU%d\n",
 		       smp_processor_id(), b->cpu);
+
+		if (!cpu_online(b->cpu)) {
+			cancel_delayed_work(&b->work);
+			return;
+		}
 	}
 	sync_buffer(b->cpu);
 
-- 
1.5.4.5

Signed-off-by: Chris J Arges <arges@xxxxxxxxxxxxxxxxxx>




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