From: Avi Kivity <avi@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@elte.hu>,
Frederic Weisbecker <fweisbec@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>
Cc: kvm-devel <kvm@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: ftrace/perf_event leak
Date: Wed, 01 Sep 2010 11:42:13 +0300 [thread overview]
Message-ID: <4C7E11E5.1040402@redhat.com> (raw)
I recently added perf_event support to kvm_stat, to display kvm
tracepoints as statistics (I'd like to fold this to tools/perf
eventually, but that's another story). However I'm seeing a resource
leak - after I quit the tool, there are quite a few references into the
kvm module:
kvm_intel 43655 0
kvm 272984 269 kvm_intel
The tool is just a python script that reads
/sys/kernel/debug/tracing/events/kvm to find out which events are
available, uses perf_event_open() to create one group per cpu to which a
lot of events are attached. The only special thing I can think of is
that we use an ioctl to attach a filter to many perf_event descriptors.
You can find the source at
http://git.kernel.org/?p=virt/kvm/qemu-kvm.git;a=blob_plain;f=kvm/kvm_stat;hb=5bd5f131b50cb373ff4e2a3632c6dad00a1f0b55.
All it needs are the kvm modules loaded; no need to actually run a
guest. Run as root.
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
next reply other threads:[~2010-09-01 8:42 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-01 8:42 Avi Kivity [this message]
2010-09-01 9:04 ` ftrace/perf_event leak Peter Zijlstra
2010-09-01 9:26 ` Avi Kivity
2010-09-01 9:35 ` Peter Zijlstra
2010-09-01 9:38 ` Li Zefan
2010-09-01 9:41 ` Peter Zijlstra
2010-09-01 10:38 ` Avi Kivity
2010-09-01 11:02 ` Peter Zijlstra
2010-09-01 11:07 ` Ingo Molnar
2010-09-01 12:15 ` Frederic Weisbecker
2010-09-01 13:59 ` Steven Rostedt
2010-09-01 17:32 ` Ingo Molnar
2010-09-02 1:20 ` Li Zefan
2010-09-09 19:45 ` [tip:perf/core] perf, trace: Fix module leak tip-bot for Li Zefan
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