Messages in this thread | | | Date | Thu, 27 Nov 2008 10:34:19 -0500 (EST) | From | Steven Rostedt <> | Subject | Re: about use wild cards for set_ftrace_filter and so on |
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On Thu, 27 Nov 2008, walimis wrote:
> > I encountered an issue when using ftrace. > We know that we can use wild cards to set set_ftrace_filter, but there's > problem when using such as "echo h* > /debug/tracing/set_ftrace_filter". > If there are files named with "h" prefix in current directory, echo "h*" > will echo these files' name to set_ftrace_filter, not "h*". > For example: > > #cat /debug/tracing/available_filter_functions |grep ^hr |wc -l > 23 > #ls > #touch hraa hrdd > #ls > hraa hrdd > #echo hr* > /debug/tracing/set_ftrace_filter > #cat /debug/tracing/set_ftrace_filter > > No output in /debug/tracing/set_ftrace_filter! > If we use "" to enclose wild cards, it works: > > #ls > hraa hrdd > #echo "hr*" > /debug/tracing/set_ftrace_filter > #cat /debug/tracing/set_ftrace_filter |wc -l > 23 > > This problem can lead to unexpected result if current directory has a > lot of files. > I suppose that we can add some notes to document, so a patch attached.
Using TB? It's best to inline the patch, that way I can comment on it better.
Anyway, you should fix the example. I also recommend a single quote over double, to prevent any other translation that bash might do.
The example in ftrace.txt should be:
# echo 'hrtimer_*' > /debug/tracing/set_ftrace_filter
Thanks,
-- Steve
/me goes back to eating turkeys.
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