* [PATCH] x86: print microcode revision on PEBs errors
@ 2013-10-30 19:31 Michael S. Tsirkin
2013-10-30 19:36 ` Joe Perches
2013-10-31 8:15 ` Ingo Molnar
0 siblings, 2 replies; 3+ messages in thread
From: Michael S. Tsirkin @ 2013-10-30 19:31 UTC (permalink / raw)
Cc: Peter Zijlstra, Paul Mackerras, Ingo Molnar,
Arnaldo Carvalho de Melo, Thomas Gleixner, H. Peter Anvin, x86,
Stephane Eranian, Andi Kleen, linux-kernel
On Sandy bridge CPUs with old microcode, PEBs
fails and suggests a microcode update.
Print out the required and the actual revision to
make it easier to figure out what's wrong.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
arch/x86/kernel/cpu/perf_event_intel.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index f31a165..81f2789 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -2105,6 +2105,8 @@ static int intel_snb_pebs_broken(int cpu)
}
}
+ pr_info("PEBS checking: microcode 0x%x min legal 0x%x\n",
+ cpu_data(cpu).microcode, rev);
return (cpu_data(cpu).microcode < rev);
}
--
MST
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] x86: print microcode revision on PEBs errors
2013-10-30 19:31 [PATCH] x86: print microcode revision on PEBs errors Michael S. Tsirkin
@ 2013-10-30 19:36 ` Joe Perches
2013-10-31 8:15 ` Ingo Molnar
1 sibling, 0 replies; 3+ messages in thread
From: Joe Perches @ 2013-10-30 19:36 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Peter Zijlstra, Paul Mackerras, Ingo Molnar,
Arnaldo Carvalho de Melo, Thomas Gleixner, H. Peter Anvin, x86,
Stephane Eranian, Andi Kleen, linux-kernel
On Wed, 2013-10-30 at 21:31 +0200, Michael S. Tsirkin wrote:
> On Sandy bridge CPUs with old microcode, PEBs
> fails and suggests a microcode update.
> Print out the required and the actual revision to
> make it easier to figure out what's wrong.
[]
> diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
[]
> @@ -2105,6 +2105,8 @@ static int intel_snb_pebs_broken(int cpu)
> }
> }
>
> + pr_info("PEBS checking: microcode 0x%x min legal 0x%x\n",
> + cpu_data(cpu).microcode, rev);
Maybe only emit this with microcode < rev
otherwise it gets emitted once for each online cpu
> return (cpu_data(cpu).microcode < rev);
> }
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] x86: print microcode revision on PEBs errors
2013-10-30 19:31 [PATCH] x86: print microcode revision on PEBs errors Michael S. Tsirkin
2013-10-30 19:36 ` Joe Perches
@ 2013-10-31 8:15 ` Ingo Molnar
1 sibling, 0 replies; 3+ messages in thread
From: Ingo Molnar @ 2013-10-31 8:15 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Peter Zijlstra, Paul Mackerras, Ingo Molnar,
Arnaldo Carvalho de Melo, Thomas Gleixner, H. Peter Anvin, x86,
Stephane Eranian, Andi Kleen, linux-kernel
* Michael S. Tsirkin <mst@redhat.com> wrote:
> On Sandy bridge CPUs with old microcode, PEBs
> fails and suggests a microcode update.
> Print out the required and the actual revision to
> make it easier to figure out what's wrong.
>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> arch/x86/kernel/cpu/perf_event_intel.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
> index f31a165..81f2789 100644
> --- a/arch/x86/kernel/cpu/perf_event_intel.c
> +++ b/arch/x86/kernel/cpu/perf_event_intel.c
> @@ -2105,6 +2105,8 @@ static int intel_snb_pebs_broken(int cpu)
> }
> }
>
> + pr_info("PEBS checking: microcode 0x%x min legal 0x%x\n",
> + cpu_data(cpu).microcode, rev);
That's not a very informative message though.
Something like:
"x86/perf/intel: PEBS turned off due to too old microcode version 0x%x\n"
"x86/perf/intel: Minimum required microcode version for PEBS: 0x%x\n"
would work better I think.
Also, only output this once, and only output it if the check
_fails_.
> return (cpu_data(cpu).microcode < rev);
Btw., please also fix the return statement, it doesn't need
parentheses.
Thanks,
Ingo
^ permalink raw reply [flat|nested] 3+ messages in thread
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2013-10-30 19:31 [PATCH] x86: print microcode revision on PEBs errors Michael S. Tsirkin
2013-10-30 19:36 ` Joe Perches
2013-10-31 8:15 ` Ingo Molnar
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