On 7/3/2013 2:55 AM, Peter Zijlstra wrote:
On Tue, Jul 02, 2013 at 05:50:29PM -0700, Linus Torvalds wrote:
On Mon, Jul 1, 2013 at 2:03 AM, Ingo Molnar <mi...@kernel.org> wrote:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
perf-core-for-linus
Kernel improvements:
* AMD IOMMU uncore PMU support by Suravee Suthikulpanit001a
This one prints a really annoying error message if you're not on an
AMD platform:
+ if (!amd_iommu_pc_supported()) {
+ pr_err("perf: amd_iommu PMU not installed. No support!\n");
+ return -ENODEV;
+ }
and you know what? That's not acceptable. It damn well is *not* an
error to not have an AMD IOMMU.
It should - at most - be a pr_info(). Maybe nothing at all. "pr_err()"
is just totally out of line.
Quite; it prints enough stuff when it does find one so I'm all for
scrapping that one print when it doesn't find it.
Sorry for not seeing that; when I initially read that code I thought it was for
the case where the hardware was expected to have the device but we couldn't
find it for some weird reason.
---
Subject: perf, amd: Do not print an error when the device is not present
As Linus said its not an error to not have an AMD IOMMU; esp. when you're not
even running on an AMD platform.
Requested-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Peter Zijlstra <pet...@infradead.org>
---
arch/x86/kernel/cpu/perf_event_amd_iommu.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event_amd_iommu.c
b/arch/x86/kernel/cpu/perf_event_amd_iommu.c
index 0db655e..639d128 100644
--- a/arch/x86/kernel/cpu/perf_event_amd_iommu.c
+++ b/arch/x86/kernel/cpu/perf_event_amd_iommu.c
@@ -491,10 +491,8 @@ static struct perf_amd_iommu __perf_iommu = {
static __init int amd_iommu_pc_init(void)
{
/* Make sure the IOMMU PC resource is available */
- if (!amd_iommu_pc_supported()) {
- pr_err("perf: amd_iommu PMU not installed. No support!\n");
+ if (!amd_iommu_pc_supported())
return -ENODEV;
- }
_init_perf_amd_iommu(&__perf_iommu, "amd_iommu");
Linus, sorry for inconvenience. This is a mistake in my part.
Peter, thank you for sending out the patch quickly. I have checked the
patch and this is okay.
Suravee
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