From: Andi Kleen <andi@firstfloor.org>
To: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@redhat.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
Jim Keniston <jkenisto@us.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Vegard Nossum <vegard.nossum@gmail.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Steven Rostedt <rostedt@goodmis.org>,
Andi Kleen <andi@firstfloor.org>, Avi Kivity <avi@redhat.com>,
"Frank Ch. Eigler" <fche@redhat.com>,
Satoshi Oshima <satoshi.oshima.fk@hitachi.com>,
systemtap-ml <systemtap@sources.redhat.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFC][PROTO][PATCH -tip 0/7] kprobes: support jump optimization on x86
Date: Wed, 8 Apr 2009 13:06:02 +0200 [thread overview]
Message-ID: <20090408110602.GA14687@one.firstfloor.org> (raw)
In-Reply-To: <20090408101056.GA14482@elte.hu>
On Wed, Apr 08, 2009 at 12:10:56PM +0200, Ingo Molnar wrote:
>
> * Masami Hiramatsu <mhiramat@redhat.com> wrote:
>
> > > But can we consider it as a small problem, assuming that kprobes
> > > are rarely intended for a massive use in once? I guess that
> > > usually, not a lot of functions are probed simultaneously.
> >
> > Hm, yes and no, systemtap may use massive kprobes, because it
> > supports "wildcard" probes. However, optimizing in default may be
> > acceptable.
>
> 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.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2009-04-08 11:03 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-06 21:41 [RFC][PROTO][PATCH -tip 0/7] kprobes: support jump optimization on x86 Masami Hiramatsu
2009-04-08 1:17 ` Frederic Weisbecker
2009-04-08 1:51 ` Masami Hiramatsu
2009-04-08 10:10 ` Ingo Molnar
2009-04-08 11:06 ` Andi Kleen [this message]
2009-04-08 13:01 ` Frank Ch. Eigler
2009-04-08 15:00 ` Masami Hiramatsu
2009-04-08 15:39 ` Ingo Molnar
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