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* [PATCH] trace-cmd: Only support tsc2nsec if multiplier or shift is non-zero
@ 2021-03-31 17:24 Steven Rostedt
  0 siblings, 0 replies; only message in thread
From: Steven Rostedt @ 2021-03-31 17:24 UTC (permalink / raw)
  To: Linux Trace Devel

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

perf on KVM guests does not support the multiplier or shift even though the
page has those fields. Instead, they are set to zeros. Only consider the
tsc2nsec supported if one of those is non-zero.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---

This applies on top of:

   https://patchwork.kernel.org/project/linux-trace-devel/list/?series=457305

 tracecmd/trace-record.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index bebecdbd..f642a5e3 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -5808,7 +5808,8 @@ static int get_tsc_nsec(int *shift, int *mult)
 	if (i < cpus)
 		return -1;
 
-	supported = 1;
+	if (cpu_shift || cpu_mult)
+		supported = 1;
 out:
 	if (supported < 0)
 		return -1;
-- 
2.29.2


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2021-03-31 17:24 [PATCH] trace-cmd: Only support tsc2nsec if multiplier or shift is non-zero Steven Rostedt

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