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authorPaul Durrant <paul.durrant@citrix.com>2016-08-04 14:44:14 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2016-09-05 13:47:01 -0400
commit0a852417564bc59441dc09509beacf7b49bc1e57 (patch)
treea27b04adbdaa3681d8797dab9097df2aca9464fd /docs/tracing.txt
parente87d397e5ef66276ccc49b829527d605ca07d0ad (diff)
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trace: add syslog tracing backend
This patch adds a tracing backend which sends output using syslog(). The syslog backend is limited to POSIX compliant systems. openlog() is called with facility set to LOG_DAEMON, with the LOG_PID option. Trace events are logged at level LOG_INFO. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Message-id: 1470318254-29989-1-git-send-email-paul.durrant@citrix.com Cc: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'docs/tracing.txt')
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1 files changed, 12 insertions, 0 deletions
diff --git a/docs/tracing.txt b/docs/tracing.txt
index 29f2f9a..e62444c 100644
--- a/docs/tracing.txt
+++ b/docs/tracing.txt
@@ -192,6 +192,18 @@ After running qemu by root user, you can get the trace:
Restriction: "ftrace" backend is restricted to Linux only.
+=== Syslog ===
+
+The "syslog" backend sends trace events using the POSIX syslog API. The log
+is opened specifying the LOG_DAEMON facility and LOG_PID option (so events
+are tagged with the pid of the particular QEMU process that generated
+them). All events are logged at LOG_INFO level.
+
+NOTE: syslog may squash duplicate consecutive trace events and apply rate
+ limiting.
+
+Restriction: "syslog" backend is restricted to POSIX compliant OS.
+
==== Monitor commands ====
* trace-file on|off|flush|set <path>