Re: [PATCH 3/3] tracing/ksym_tracer: support quick clear for ksym_trace_filter

[Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>]

K.Prasad wrote:
> On Wed, Jul 22, 2009 at 11:25:14AM +0800, Xiao Guangrong wrote:
>> It's rather bored to clear symbol one by one in ksym_trace_filter
>> file, so, this patch can let ksym_trace_filter file support quick
>> clear, we can write "0" to this file, it can clear all symbols
>>
>> for example:
>>  # cat ksym_trace_filter
>>  ksym_filter_head:rw-
>>  global_trace:rw-
>>  # echo 0 > ksym_trace_filter
>>  # cat ksym_trace_filter
>>  #
>>
> 
> It's nice to have this feature added and the other patches fix issues in
> ksym tracer. Can you have this patch add the capability to clear all
> breakpoints in one-shot through wild-cards?
> 

It already can clear all breakpoints in one-shot by write "0" to
ksym_trace_filter file, do you means that we need to support other
way for it? like:

echo > ksym_trace_filter
echo "*:---" > ksym_trace_filter

IMHO, one way to clear all breakpoints is enough, no need to add
more code for the same function, for example, in trace events filter,
only echo 0 > filter can properly clear all filters.

Are you sure other way is necessary? 

Thanks,
Xiao

> Ingo wanted something like "echo "*:---" > ksym_trace_filter". The patch
> I sent here: http://lkml.org/lkml/2009/6/20/73 implements the same. You
> may want to implement something on those lines.
> 
> Thanks,
> K.Prasad
> 
> 
>