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From: Milian Wolff <milian.wolff@kdab.com>
To: linux-perf-users@vger.kernel.org
Subject: LBR unwinding for user defined dynamic trace point
Date: Tue, 15 Sep 2015 15:12:02 +0200	[thread overview]
Message-ID: <2495974.rH49Pff4SO@milian-kdab2> (raw)

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Hey all,

I just tried to use LBR with a user defined dynamic trace point and get a 
strange error message:

$ sudo perf probe -x /lib64/libc.so.6 malloc
$ sudo perf record -e probe_libc:malloc --call-graph lbr -F 1000 ./foo
Error:
The sys_perf_event_open() syscall returned with 95 (Operation not supported) 
for event (probe_libc:malloc).
/bin/dmesg may provide additional information.
No CONFIG_PERF_EVENTS=y kernel support configured?

When I do the same with the Dwarf unwinder, it works just fine. Using the LBR 
unwinder with a performance counter like instructions also works fine. Does 
anyone know what the issue is here?
-- 
Milian Wolff | milian.wolff@kdab.com | Software Engineer
KDAB (Deutschland) GmbH&Co KG, a KDAB Group company
Tel: +49-30-521325470
KDAB - The Qt Experts

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             reply	other threads:[~2015-09-15 13:12 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-15 13:12 Milian Wolff [this message]
2015-09-15 14:02 ` LBR unwinding for user defined dynamic trace point Andi Kleen
2015-09-16  9:55   ` Milian Wolff
2015-09-16 18:56     ` Andi Kleen
2016-04-07 15:05       ` Milian Wolff
2016-04-07 15:55         ` Andi Kleen

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