From: Ingo Molnar <mingo@kernel.org>
Date: Thu, 1 Jan 2015 21:21:22 +0000 (+0100)
Subject: Merge tag 'pr-20141223-x86-vdso' of git://git.kernel.org/pub/scm/linux/kernel/git... 
X-Git-Tag: v3.19-rc4~2^2
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=2aba73a6146bb85d4a42386ca41dec0f4aa4b3ad;p=linux.git

Merge tag 'pr-20141223-x86-vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux into x86/urgent

Pull VDSO fix from Andy Lutomirski:

 "This is hopefully the last vdso fix for 3.19.  It should be very
  safe (it just adds a volatile).

  I don't think it fixes an actual bug (the __getcpu calls in the
  pvclock code may not have been needed in the first place), but
  discussion on that point is ongoing.

  It also fixes a big performance issue in 3.18 and earlier in which
  the lsl instructions in vclock_gettime got hoisted so far up the
  function that they happened even when the function they were in was
  never called.  n 3.19, the performance issue seems to be gone due to
  the whims of my compiler and some interaction with a branch that's
  now gone.

  I'll hopefully have a much bigger overhaul of the pvclock code
  for 3.20, but it needs careful review."

Signed-off-by: Ingo Molnar <mingo@kernel.org>
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2aba73a6146bb85d4a42386ca41dec0f4aa4b3ad