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Date: Fri, 20 Dec 2013 08:21:00 -0000
From: Ingo Molnar <mingo@kernel.org>
To: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>, linux-arch@vger.kernel.org,	Ananth N Mavinakayanahalli <ananth@in.ibm.com>,	Sandeepa Prabhu <sandeepa.prabhu@linaro.org>, x86@kernel.org,	lkml <linux-kernel@vger.kernel.org>,	"Steven Rostedt (Red Hat)" <rostedt@goodmis.org>,	systemtap@sourceware.org, "David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH -tip v6 00/22] kprobes: introduce NOKPROBE_SYMBOL(), cleanup and fixes crash bugs
Message-ID: <20131220082056.GA15934@gmail.com>
References: <20131219090353.14309.15496.stgit@kbuild-fedora.novalocal> <y0m38loefhx.fsf@fche.csb> <52B3C5E6.2040802@hitachi.com>
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* Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> wrote:

> >  But a closer look indicates that the insertion of kprobes is 
> > taking about three (!!) orders of magnitude longer than before, as 
> > judged by the rate of increase of 'wc -l 
> > /sys/kernel/debug/kprobes/list'.
> 
> Right, because kprobes are not designed for thousands of probes.

Then this needs to be fixed, because right now this bug is making it 
near impossible to properly test kprobes robustness.

For example a hash table (hashed by probe address) could be used in 
addition to the list, to speed up basic operations.

Thanks,

	Ingo