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From: Stephen Boyd <sboyd@codeaurora.org>
To: linux-kernel@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Subject: [RFC/PATCH 0/3] static keys for debugobjects
Date: Fri,  6 Apr 2012 00:03:15 -0700	[thread overview]
Message-ID: <1333695798-2917-1-git-send-email-sboyd@codeaurora.org> (raw)

Building in debugobjects support without enabling debugobjects
by default is useful in test scenarios where recompiling isn't
an option. Moving this interface to static keys/jump labels should
allow us to always have this code compiled in without worrying about
performance overhead when it's disabled.

RFC because I don't have any numbers to back this up and it's debug
code. I took a stab at using perf but I don't think the x86 machine
I was using had good enough stuff to see i-cache misses or things
like that. Hints on what to do to actually prove this is useful are
appreciated.

This is based on the perf/jump-labels branch in the tip tree:

 git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf/jump-labels

Stephen Boyd (3):
  timer: Move debugobjects.h include to timer.c
  init: Initialize jump_labels before early parameters
  debugobjects: Use static keys for debug_objects_enabled

 include/linux/debugobjects.h |   94 +++++++++++++++++++++++++++++++++++++-----
 include/linux/timer.h        |    1 -
 init/main.c                  |    4 +-
 kernel/timer.c               |    1 +
 lib/debugobjects.c           |   73 ++++++++++++--------------------
 5 files changed, 113 insertions(+), 60 deletions(-)

-- 
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.


             reply	other threads:[~2012-04-06  7:03 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-06  7:03 Stephen Boyd [this message]
2012-04-06  7:03 ` [PATCH 1/3] timer: Move debugobjects.h include to timer.c Stephen Boyd
2012-04-06  7:03 ` [RFC/PATCH 2/3] init: Initialize jump_labels before early parameters Stephen Boyd
2012-04-06  7:03 ` [RFC/PATCH 3/3] debugobjects: Use static keys for debug_objects_enabled Stephen Boyd

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