From: Jonathan Lebon Date: Fri, 19 Dec 2014 21:03:11 +0000 (-0500) Subject: stapprobes.3stap: document new tracepoint syntax X-Git-Tag: release-2.7~114^2~2 X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=970d1d064273ec210a0c57f01977af808a2e8b29;p=systemtap.git stapprobes.3stap: document new tracepoint syntax Talk about the new system:name syntax. Also update the sched_switch tracepoint example, which no longer shares the $rq argument. --- diff --git a/man/stapprobes.3stap b/man/stapprobes.3stap index 645c77a12..29fc7bf2f 100644 --- a/man/stapprobes.3stap +++ b/man/stapprobes.3stap @@ -1181,22 +1181,27 @@ Tracepoint probes look like: .BR kernel.trace("name") . The tracepoint name string, which may contain the usual wildcard characters, is matched against the names defined by the kernel -developers in the tracepoint header files. +developers in the tracepoint header files. To restrict the search to +specific subsystems (e.g. sched, ext3, etc...), the following syntax +can be used: +.BR kernel.trace("system:name") . +The tracepoint system string may also contain the usual wildcard +characters. The handler associated with a tracepoint-based probe may read the optional parameters specified at the macro call site. These are named according to the declaration by the tracepoint author. For example, the tracepoint probe -.BR kernel.trace("sched_switch") +.BR kernel.trace("sched:sched_switch") provides the parameters -.BR $rq ", " $prev ", and " $next . +.BR $prev " and " $next . If the parameter is a complex type, as in a struct pointer, then a script can access fields with the same syntax as DWARF $target variables. Also, tracepoint parameters cannot be modified, but in guru-mode a script may modify fields of parameters. -The name of the tracepoint is available in -.BR $$name , +The subsystem and name of the tracepoint are available in +.BR $$system " and " $$name and a string of name=value pairs for all parameters of the tracepoint is available in .BR $$vars " or " $$parms .