Re: [RFC][PROTO][PATCH -tip 0/7] kprobes: support jump optimizationon x86

From: Masami Hiramatsu
Date: Wed Apr 08 2009 - 11:02:29 EST


Frank Ch. Eigler wrote:
> On Wed, Apr 08, 2009 at 01:06:02PM +0200, Andi Kleen wrote:
>> [...]
>>> I'm curious: what is the biggest kprobe count you've ever seen, in
>>> the field? 1000? 10,000? 100,000? More?
>> The limit is iirc how much memory the gcc compiling the probes program
>> consumes before running out of swap space.
>
> On a machine with lots of free RAM, gcc will not hold itself back. On
> my home server, a 40000-kprobe script compiled (pass 4) in about 4
> seconds using about 200MB RAM.

Hm, when 40,000 kprobes are optimized, it will consume less than 8MB ...
I guess that is acceptable for recent machines.

Thank you,

--
Masami Hiramatsu

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

e-mail: mhiramat@xxxxxxxxxx

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