From 3faf22ef4465d064617dee524c97afa8d4400d9c Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 12 Jan 2021 16:58:58 +0000 Subject: [PATCH] trace: document how to specify multiple --trace patterns MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Stefan Hajnoczi Reviewed-by: Philippe Mathieu-Daudé Message-id: 20210112165859.225534-2-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi --- docs/devel/tracing.rst | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/docs/devel/tracing.rst b/docs/devel/tracing.rst index af395e957de7..e8f9b82c5e04 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 -instead:: +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