tree 063b71edb357955d616a4c7543747ea0c3c61007
parent 7ffd49409f2fb2d2c5e57cb9f7cfa714f71a45a6
author Sherry Yang <sherryy@android.com> 1501359851 -0700
committer Mengjiao Yang <sherryy@google.com> 1504224374 -0700

FROMLIST: android: binder: Add global lru shrinker to binder

(from https://patchwork.kernel.org/patch/9928615/)

Hold on to the pages allocated and mapped for transaction
buffers until the system is under memory pressure. When
that happens, use linux shrinker to free pages. Without
using shrinker, patch "android: binder: Move buffer out
of area shared with user space" will cause a significant
slow down for small transactions that fit into the first
page because free list buffer header used to be inlined
with buffer data.

In addition to prevent the performance regression for
small transactions, this patch improves the performance
for transactions that take up more than one page.

Modify alloc selftest to work with the shrinker change.

Test: Run memory intensive applications (Chrome and Camera)
to trigger shrinker callbacks. Binder frees memory as expected.
Test: Run binderThroughputTest with high memory pressure
option enabled.

Bug: 63926541
Change-Id: I3abfc43b405e7e0a6228da37e0689a4b944f0e00
Signed-off-by: Sherry Yang <sherryy@android.com>