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authorRobert Richter <robert.richter@amd.com>2012-08-22 09:23:51 +0200
committerRobert Richter <robert.richter@amd.com>2012-08-27 14:49:39 +0200
commit61bccf191fe2d55b8d003b4ea3f94913745aaefa (patch)
treef91fb75d321f775bf4ea59e35c0534320d7c4597
parent81ff3478d9ba7f0b48b0abef740e542fd83adf79 (diff)
downloadlinux-61bccf191fe2d55b8d003b4ea3f94913745aaefa.tar.bz2
oprofile: Remove 'WQ on CPUx, prefer CPUy' warning
Under certain workloads we see the following warnings: WQ on CPU0, prefer CPU1 WQ on CPU0, prefer CPU2 WQ on CPU0, prefer CPU3 It warns the user that the wq to access a per-cpu buffers runs not on the same cpu. This happens if the wq is rescheduled on a different cpu than where the buffer is located. This was probably implemented to detect performance issues. Not sure if there actually is one as the buffers are copied to a single buffer anyway which should be the actual bottleneck. We wont change WQ implementation. Since a user can do nothing the warning is pointless. Removing it. Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Robert Richter <robert.richter@amd.com>
-rw-r--r--drivers/oprofile/cpu_buffer.c11
1 files changed, 3 insertions, 8 deletions
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index b8ef8ddcc292..8aa73fac6ad4 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -451,14 +451,9 @@ static void wq_sync_buffer(struct work_struct *work)
{
struct oprofile_cpu_buffer *b =
container_of(work, struct oprofile_cpu_buffer, work.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;
- }
+ if (b->cpu != smp_processor_id() && !cpu_online(b->cpu)) {
+ cancel_delayed_work(&b->work);
+ return;
}
sync_buffer(b->cpu);