From: Andi Kleen <andi@firstfloor.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Andi Kleen <andi@firstfloor.org>,
mingo@kernel.org, linux-kernel@vger.kernel.org,
stable@vger.kernel.org, eranian@google.com,
Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH 1/2] Fix perf LBR filtering
Date: Fri, 26 Apr 2013 21:46:33 +0200 [thread overview]
Message-ID: <20130426194633.GF16732@two.firstfloor.org> (raw)
In-Reply-To: <20130426075601.GB8669@dyad.programming.kicks-ass.net>
>
> OK, so how about we use something like:
>
> is_kernel_text() || is_module_text_address()
is_module_text_address() has to walk all modules.
A random system with a distro kernel I checked has 101 modules loaded.
16 * 101 = too much
I don't think you want to spend that many cycles in the NMI
handler for a dubious feature. Ok in theory you could
add something with binary search, but that would be quite
a bit of effort and it would be probably challenging
to do that all NMI safe.
Also it wouldn't work for all these new kernel JITs people
are doing of course.
Still think my patch is the best so far? (plus the missing
root check)
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2013-04-26 19:46 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-24 23:04 [PATCH 1/2] Fix perf LBR filtering Andi Kleen
2013-04-24 23:04 ` [PATCH 2/2] perf, x86: Don't allow unusual PEBS raw flags Andi Kleen
2013-04-29 22:16 ` Stephane Eranian
2013-04-29 22:34 ` Andi Kleen
2013-04-29 23:05 ` Stephane Eranian
2013-05-02 7:37 ` Peter Zijlstra
2013-05-06 17:44 ` Stephane Eranian
2013-05-06 18:52 ` Peter Zijlstra
2013-05-06 22:43 ` Stephane Eranian
2013-05-07 6:48 ` Ingo Molnar
2013-05-07 8:48 ` Peter Zijlstra
2013-05-07 11:04 ` Ingo Molnar
2013-05-07 8:43 ` Peter Zijlstra
2013-04-24 23:20 ` [PATCH 1/2] Fix perf LBR filtering Ben Hutchings
2013-04-24 23:24 ` Greg KH
2013-04-25 16:25 ` Peter Zijlstra
2013-04-25 16:41 ` Andi Kleen
2013-04-25 16:48 ` Peter Zijlstra
2013-04-25 17:00 ` Andi Kleen
2013-04-25 17:18 ` Peter Zijlstra
2013-04-25 17:42 ` Andi Kleen
2013-04-26 7:56 ` Peter Zijlstra
2013-04-26 19:46 ` Andi Kleen [this message]
2013-05-01 11:51 ` Ingo Molnar
2013-05-01 11:55 ` Ingo Molnar
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