tag 03efef6ca8392d88662f7e202e084c86f64d1440
tagger The Android Open Source Project <initial-contribution@android.com> Mon Mar 01 12:16:34 2021 -0800
object 9ae674f6f6964dbd4d261beda92755735f7b6d8a

Android 11.0.0 Release 32 (RQ2A.210305.006)

commit 9ae674f6f6964dbd4d261beda92755735f7b6d8a
author Kostya Kortchinsky <kostyak@google.com> Mon Aug 24 14:13:12 2020 -0700
committer Christopher Ferris <cferris@google.com> Tue Aug 25 22:46:02 2020 -0700
tree c8df1e08210befab8ebf0bccd3aaec6089579594
parent 4ba5deef67ae06acf20a5da4fb87ceeaa40aa0e4

[scudo][standalone] Skip irrelevant regions during release

With the 'new' way of releasing on 32-bit, we iterate through all the
regions in between `First` and `Last`, which covers regions that do not
belong to the class size we are working with. This is effectively wasted
cycles.

With this change, we add a `SkipRegion` lambda to `releaseFreeMemoryToOS`
that will allow the release function to know when to skip a region.
For the 64-bit primary, since we are only working with 1 region, we never
skip.

Reviewed By: hctim

Differential Revision: https://reviews.llvm.org/D86399

Bug: 164309199

Test: Ran all unit tests (bionic, libmemunreachable, scudo).
Test: Ran all perf benchmarks before and after and verified no decrease.

GitOrigin-RevId: bd5ca4f0ed4adfa29150c18a621acb3e71d41450
Change-Id: I1fcbe91c117f4e4835f1dabe05d4c47f9604d015
Merged-In: I1fcbe91c117f4e4835f1dabe05d4c47f9604d015
(cherry picked from commit bcd746b334c91b8c2b925a5cb8f91b846edb918d)