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authorStefan Hajnoczi <stefanha@redhat.com>2012-11-05 08:48:29 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2012-11-16 13:12:13 +0100
commit8f5a0fb1f4e3167b893e3a4272446e2cf1568058 (patch)
treee3187b84bc6c75fb16bf930775b8920cdd761c4b
parentddde8acc989d9e59b37605d438d5cb6b5ce8fbae (diff)
downloadqemu-arm-8f5a0fb1f4e3167b893e3a4272446e2cf1568058.tar.gz
trace: document '-' syntax for disabling events
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
-rw-r--r--docs/tracing.txt4
1 files changed, 4 insertions, 0 deletions
diff --git a/docs/tracing.txt b/docs/tracing.txt
index c541133368..79014093db 100644
--- a/docs/tracing.txt
+++ b/docs/tracing.txt
@@ -139,6 +139,10 @@ having a common prefix in a batch. For example, virtio-blk trace events could
be enabled using:
trace-event virtio_blk_* on
+If a line in the "-trace events=<file>" file begins with a '-', the trace event
+will be disabled instead of enabled. This is useful when a wildcard was used
+to enable an entire family of events but one noisy event needs to be disabled.
+
== Trace backends ==
The "tracetool" script automates tedious trace event code generation and also