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| author | Robert Richter <robert.richter@amd.com> | 2012-08-22 09:23:51 +0200 |
|---|---|---|
| committer | Robert Richter <robert.richter@amd.com> | 2012-08-27 14:49:39 +0200 |
| commit | 61bccf191fe2d55b8d003b4ea3f94913745aaefa (patch) | |
| tree | f91fb75d321f775bf4ea59e35c0534320d7c4597 | |
| parent | oprofile, s390: Fix uninitialized memory access when writing to oprofilefs (diff) | |
| download | linux-61bccf191fe2d55b8d003b4ea3f94913745aaefa.tar.xz linux-61bccf191fe2d55b8d003b4ea3f94913745aaefa.zip | |
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.c | 11 |
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); |