From: Mike Galbraith <umgwanakikbuti@gmail.com>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Subject: why is CONFIG_FRAME_POINTER=y so expensive?
Date: Mon, 22 Aug 2016 08:17:51 +0200 [thread overview]
Message-ID: <1471846671.4139.50.camel@gmail.com> (raw)
Greetings,
tbench 8 throughput on my i4790 box:
1 2 3 avg
master 3769.95 3759.28 3762.83 3764.02 1.000
master-framepointer 3476.73 3453.52 3460.62 3463.62 .920
Does anyone know why the performance impact is this large?
The only thing I found googling was a reference to 3 arg lea using rbp
or r13 being slow, which wasn't particularly helpful. Nor was staring
at asm deltas with non-expert eyeballs.
-Mike
reply other threads:[~2016-08-22 6:17 UTC|newest]
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