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| author | Peter Maydell <peter.maydell@linaro.org> | 2014-02-21 14:38:23 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2014-02-21 14:38:23 +0000 |
| commit | 7a87a7b3e4213f7b020e434b14f8890d41b93fb7 (patch) | |
| tree | 8ab8b8c40280a3693718f5f095a61d7ab64407bb /docs/tracing.txt | |
| parent | e607784fedbf235599dc9a7ed96b624f6ecd1dd5 (diff) | |
| parent | 94783de6fe746f86a357bc4e3e6759f7f8ad3b39 (diff) | |
Merge remote-tracking branch 'remotes/stefanha/tags/tracing-pull-request' into staging
Tracing pull request
# gpg: Signature made Wed 19 Feb 2014 15:42:20 GMT using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35 775A 9CA4 ABB3 81AB 73C8
* remotes/stefanha/tags/tracing-pull-request:
trace-events: Fix typo in "offset"
Add ust generated files to .gitignore
Update documentation for LTTng ust tracing
Adapt Makefiles to the new LTTng ust interface
Modified the tracetool framework for LTTng 2.x
Fix configure script for LTTng 2.x
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'docs/tracing.txt')
| -rw-r--r-- | docs/tracing.txt | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/docs/tracing.txt b/docs/tracing.txt index bfc261bcaf..bf2e15ce30 100644 --- a/docs/tracing.txt +++ b/docs/tracing.txt @@ -214,6 +214,42 @@ The "ust" backend uses the LTTng Userspace Tracer library. There are no monitor commands built into QEMU, instead UST utilities should be used to list, enable/disable, and dump traces. +Package lttng-tools is required for userspace tracing. You must ensure that the +current user belongs to the "tracing" group, or manually launch the +lttng-sessiond daemon for the current user prior to running any instance of +QEMU. + +While running an instrumented QEMU, LTTng should be able to list all available +events: + + lttng list -u + +Create tracing session: + + lttng create mysession + +Enable events: + + lttng enable-event qemu:g_malloc -u + +Where the events can either be a comma-separated list of events, or "-a" to +enable all tracepoint events. Start and stop tracing as needed: + + lttng start + lttng stop + +View the trace: + + lttng view + +Destroy tracing session: + + lttng destroy + +Babeltrace can be used at any later time to view the trace: + + babeltrace $HOME/lttng-traces/mysession-<date>-<time> + === SystemTap === The "dtrace" backend uses DTrace sdt probes but has only been tested with |