X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=contents%2Fusing-lttng%2Fcontrolling-tracing%2Fenabling-disabling-events.md;h=5c40f4cbbcc4787a6cde6fdfa1dce5cf84fc732e;hb=1bf7ee862bb9826b5b48a432af54477ae5e04ff7;hp=98828c4e9c1fa108e7ada6cd575a2cd7beebce52;hpb=c23b8cb13f54163f5090b1e21d5b24fce6cd779f;p=lttng-docs.git diff --git a/contents/using-lttng/controlling-tracing/enabling-disabling-events.md b/contents/using-lttng/controlling-tracing/enabling-disabling-events.md index 98828c4..5c40f4c 100644 --- a/contents/using-lttng/controlling-tracing/enabling-disabling-events.md +++ b/contents/using-lttng/controlling-tracing/enabling-disabling-events.md @@ -12,17 +12,17 @@ in source code/binary program, logical processor and time capturing some payload) being recorded as trace data. This specific condition is composed of: - 1. A **domain** (kernel, user space, `java.util.loggin`, or log4j) + 1. A **domain** (kernel, user space, `java.util.logging`, or log4j) (required). 2. One or many **instrumentation points** in source code or binary program (tracepoint name, address, symbol name, function name, - logger name, etc.) to be executed (required). + logger name, amongst other types of probes) to be executed + (required). 3. A **log level** (each instrumentation point declares its own log level) or log level range to match (optional; only valid for user space domain). 4. A **custom user expression**, or **filter**, that must evaluate to - _true_ when a tracepoint is executed (optional; only valid for user - space domain). + _true_ when a tracepoint is executed (optional). All conditions are specified using arguments passed to the `enable-event` command of the `lttng` tool. @@ -80,6 +80,8 @@ lttng enable-event -k --tracepoint sched_switch lttng enable-event -k --tracepoint gpio_value lttng enable-event -k --function usb_probe_device usb_probe_device lttng enable-event -k --syscall --all +lttng enable-event -k --tracepoint irq_handler_entry \ + --filter 'irq == 28 || irq == 17' The wildcard symbol, `*`, matches _anything_ and may only be used at @@ -89,8 +91,8 @@ undesired shell expansion. System call events can be enabled individually, too: -
-lttng enable-event -k --syscall open
+
+
Since 2.6
lttng enable-event -k --syscall open lttng enable-event -k --syscall read lttng enable-event -k --syscall fork,chdir,pipe
@@ -139,7 +141,7 @@ Disabling an event does not add it to some blacklist: it simply removes it from its channel's whitelist. This is why you cannot disable an event which wasn't previously enabled. -A disabled event will not generate any trace data, even if all its +A disabled event doesn't generate any trace data, even if all its specified conditions are met. Events may be enabled and disabled at will, either when LTTng tracers