+ Revert buffer changes due to performance regression
Revert "apparmor: Use a memory pool instead per-CPU caches"

This reverts commit df323337e507a0009d3db1ea25948d4c7f320d62.

Vincent Guittot reported
  I have noticed a significant performance regression of hackbench with
  v5.5-rc1 (and -rc2 as well) on my dual node 224 cores arm64 system.
  The problem has been bisected down to the PR of apparmor :

  79e178a57dae ("Merge tag 'apparmor-pr-2019-12-03' of
  git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor").

  All hackbench tests are regressing but I have only put one below:

  - sha1 79e178a57dae ("Merge tag 'apparmor-pr-2019-12-03' of
  git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor")

  hackbench -l (256000/#grp) -g #grp
   128 groups     19.679 ±0.90%

  - previous sha1 01d1dff64662 ("Merge tag 's390-5.5-2' of
  git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux")

  hackbench -l (256000/#grp) -g #grp
   128 groups     3.1689 ±3.04%

Reported-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>
5 files changed