Messages in this thread Patch in this message | | | Date | Wed, 3 Jul 2013 09:55:42 +0200 | From | Peter Zijlstra <> | Subject | Re: [GIT PULL] perf changes for v3.11 |
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On Tue, Jul 02, 2013 at 05:50:29PM -0700, Linus Torvalds wrote: > On Mon, Jul 1, 2013 at 2:03 AM, Ingo Molnar <mingo@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 <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <peterz@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");
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