lineage: Add support for BFQIO cgroups

 * Introduce a standalone libbfqio to be picked by inputflinger,
   surfaceflinger and display HAL, without extending the VNDK.

 * This commit is based on the following patches:

  From: Steve Kondik <steve@cyngn.com>
  Date: Tue, 08 Sep 2015 02:23:41 -0700

      cutils: Add support for BFQIO cgroups

       * Add support for a custom hierarchy of cgroups on top of the BFQ
         IO scheduler. This allows us to place every thread into the
         right class (realtime/best-effort/idle) with a set up priority
         buckets depending on use case.
       * The benefit of doing this is pretty incredible from an
         interactivity standpoint. Realtime users (display/audio) benefit
         the most, resulting in glitch-free audio and jank-free video.
         Dexopting in the background no longer causes active harm to
         foreground tasks. Other tasks such as account syncing become
         invisible from the user's perspective.
       * Magic bullet? Perhaps.

      Change-Id: I4eb911395364ce46d6dcbff43e94286ded03a97d

  From: Steve Kondik <steve@cyngn.com>
  Date: Sat, 19 Sep 2015 12:43:40 -0700

      cutils: Fix copypasta in ioprio code

      Change-Id: I976693be4a6913ed2090fa32d0f8e4c93657e7e7

  From: Steve Kondik <steve@cyngn.com>
  Date: Sun, 20 Sep 2015 01:08:07 -0700

      cutils: Fix display ioprio

       * A few unwanted items are sneaking into this class resulting in
         system slowdowns. Fixit.

      Change-Id: I29033a38adf2c65535f916135d395d5147afe323

  From: Steve Kondik <steve@cyngn.com>
  Date: Sun, 20 Sep 2015 03:00:54 -0700

      cutils: Clean up ioprio grouping

       * It's now better understood what's happening system-wide due to these
         changes, so clean up the stuff which is not necessary and/or
         potentially harmful.

      Change-Id: I72178770844c1ac388a0b424b12cdc49042aec87

  From: Steve Kondik <steve@cyngn.com>
  Date: Sun, 20 Sep 2015 17:36:54 -0700

      cutils: Remove ioprio magic

       * ..and replace it with something we can call explictly where it is
         required in order to achieve the same goodness without the badness.

      Change-Id: I605b3acbc56ce82663dd6f1c9f3320d0ab75e178

  From: Zhao Wei Liew <zhaoweiliew@gmail.com>
  Date: Thu, 08 Sep 2016 20:01:29 +0800

      cutils: iosched_policy: Access BFQIO cgroup in /dev/bfqio

      AOSP doesn't mount cgroups in /sys/fs/cgroup, but in /dev/.
      Follow what AOSP does.

      Change-Id: I40d2241e3e5c41612d3a54d22981d3250f8b1ed6

Change-Id: I7d42bd6bb9176724c1e5687de14946923150ae89
3 files changed