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 <[email protected]> Signed-off-by: Robert Richter <[email protected]> --- drivers/oprofile/cpu_buffer.c | 11 +++-------- 1 files changed, 3 insertions(+), 8 deletions(-) diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c index b8ef8dd..8aa73fa 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); -- 1.7.8.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
