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To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>, Ingo Molnar <mingo@kernel.org>,        LKML <linux-kernel@vger.kernel.org>,        SystemTap <systemtap@sourceware.org>
Subject: Re: systemtap broken by removal of register_timer_hook
References: <20130403075017.GA2534@suse.de>	<CAFTL4hyYezB2ZxM-GJ70VoxOeRSG64V6u+nX2hTuhF30R-GdPg__32168.962484184$1364986928$gmane$org@mail.gmail.com>
From: fche@redhat.com (Frank Ch. Eigler)
Date: Wed, 03 Apr 2013 12:29:00 -0000
In-Reply-To: <CAFTL4hyYezB2ZxM-GJ70VoxOeRSG64V6u+nX2hTuhF30R-GdPg__32168.962484184$1364986928$gmane$org@mail.gmail.com> (Frederic Weisbecker's message of "Wed, 3 Apr 2013 13:01:23 +0200")
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Frederic Weisbecker <fweisbec@gmail.com> writes:

> [...]
> Sometimes I don't mind keeping around code in the kernel for out of
> tree users, depending on the case. But in this specific matter we have
> more standard ways to do this kind of hook: kprobes, static
> tracepoints. A tracepoint on the timer tick would be useful BTW, and
> you could reuse it.

Thanks for noticing!  IMO kprobes would be too heavyweight for this.
A new static tracepoint would be fine, especially if it passes the
same pt_regs* pointer as the former hook did.

- FChE