diff options
authorStefan Hajnoczi <stefanha@redhat.com>2021-01-12 16:58:58 +0000
committerStefan Hajnoczi <stefanha@redhat.com>2021-02-01 11:23:04 +0000
commit3faf22ef4465d064617dee524c97afa8d4400d9c (patch)
parentc6e93c9d62c47d628d993db482839a4fd38d603f (diff)
trace: document how to specify multiple --trace patterns
It is possible to repeat the --trace option to specify multiple patterns. This may be preferrable to users who do not want to create a file with a list of patterns. Suggested-by: BALATON Zoltan <balaton@eik.bme.hu> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20210112165859.225534-2-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
1 files changed, 7 insertions, 2 deletions
diff --git a/docs/devel/tracing.rst b/docs/devel/tracing.rst
index af395e957d..e8f9b82c5e 100644
--- a/docs/devel/tracing.rst
+++ b/docs/devel/tracing.rst
@@ -22,10 +22,15 @@ events::
This output comes from the "log" trace backend that is enabled by default when
``./configure --enable-trace-backends=BACKENDS`` was not explicitly specified.
-More than one trace event pattern can be specified by providing a file
+Multiple patterns can be specified by repeating the ``--trace`` option::
+ $ qemu --trace "kvm_*" --trace "virtio_*" ...
+When patterns are used frequently it is more convenient to store them in a
+file to avoid long command-line options::
$ echo "memory_region_ops_*" >/tmp/events
+ $ echo "kvm_*" >>/tmp/events
$ qemu --trace events=/tmp/events ...
Trace events