Re: [PATCH] tracing/filters: Defer pred allocation

Masami Hiramatsu
2009-09-01T12:57:02Z

Li Zefan wrote:
> Ingo Molnar wrote:
>> * Li Zefan <lizf@cn.fujitsu.com> wrote:
>>
>>> init_preds() allocates about 5392 bytes of memory (on x86_32) for
>>> a TRACE_EVENT. With my config, at system boot total memory occupied
>>> is:
>>>
>>> 5392 * (642 + 15) == 3459KB
>>>
>>> 642 == cat available_events | wc -l
>>> 15 == number of dirs in events/ftrace
>>>
>>> That's quite a lot, so we'd better defer memory allocation util
>>> it's needed, that's when filter is used.
>>>
>>> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
>>
>> Applied, thanks!
>>
>>> tracing/kprobe needs rebase after this patch..
>>
>> You mean with many probes registered it has a lot of memory
>
> I think so, if filter is used.
>
>> footprint? Instead of a rebase a merge of tracing/core into
>> tracing/kprobes would be less intrusive.
>>
>
> Yeah, I meant this patch conflicts with some patches in
> tracing/kprobe. :)

Sure, that should be a small change. :-)

Thank you!

--
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com