From db560090e4dcf19aa0909a27da473c4ac704af88 Mon Sep 17 00:00:00 2001
From: Daniel Zheng <zhengdaniel@google.com>
Date: Tue, 28 May 2024 18:25:12 -0700
Subject: [PATCH 1/2] libsnapshot: set thread priority

Read merge thread + worker thread priority from build configurations. In
the case of low memory devices, a lower priority will reduce CPU
utilization post OTA reboot.

Test: th
Change-Id: I812fccf2ca805d9686a837774e1770a2eebf979a
---
 .../libsnapshot/snapuserd/user-space-merge/merge_worker.cpp | 4 +++-
 .../libsnapshot/snapuserd/user-space-merge/read_worker.cpp  | 6 +++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs_mgr/libsnapshot/snapuserd/user-space-merge/merge_worker.cpp b/fs_mgr/libsnapshot/snapuserd/user-space-merge/merge_worker.cpp
index bd7eaca74..0f4674ced 100644
--- a/fs_mgr/libsnapshot/snapuserd/user-space-merge/merge_worker.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/user-space-merge/merge_worker.cpp
@@ -577,8 +577,10 @@ bool MergeWorker::Run() {
         SNAP_LOG(ERROR) << "Merge terminated early...";
         return true;
     }
+    auto merge_thread_priority = android::base::GetUintProperty<uint>(
+            "ro.virtual_ab.merge_thread_priority", ANDROID_PRIORITY_BACKGROUND);
 
-    if (!SetThreadPriority(ANDROID_PRIORITY_BACKGROUND)) {
+    if (!SetThreadPriority(merge_thread_priority)) {
         SNAP_PLOG(ERROR) << "Failed to set thread priority";
     }
 
diff --git a/fs_mgr/libsnapshot/snapuserd/user-space-merge/read_worker.cpp b/fs_mgr/libsnapshot/snapuserd/user-space-merge/read_worker.cpp
index d40b6d11d..35a162199 100644
--- a/fs_mgr/libsnapshot/snapuserd/user-space-merge/read_worker.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/user-space-merge/read_worker.cpp
@@ -17,8 +17,10 @@
 #include <libsnapshot/cow_format.h>
 #include <pthread.h>
 
+#include "android-base/properties.h"
 #include "read_worker.h"
 #include "snapuserd_core.h"
+#include "user-space-merge/worker.h"
 #include "utility.h"
 
 namespace android {
@@ -259,8 +261,10 @@ bool ReadWorker::Run() {
     SNAP_LOG(INFO) << "Processing snapshot I/O requests....";
 
     pthread_setname_np(pthread_self(), "ReadWorker");
+    auto worker_thread_priority = android::base::GetUintProperty<uint>(
+            "ro.virtual_ab.worker_thread_priority", ANDROID_PRIORITY_NORMAL);
 
-    if (!SetThreadPriority(ANDROID_PRIORITY_NORMAL)) {
+    if (!SetThreadPriority(worker_thread_priority)) {
         SNAP_PLOG(ERROR) << "Failed to set thread priority";
     }
 

From 28801377a5d09fce686edbd81c1d5e4d9f698e5e Mon Sep 17 00:00:00 2001
From: Daniel Zheng <zhengdaniel@google.com>
Date: Wed, 29 May 2024 10:44:09 -0700
Subject: [PATCH 2/2] libsnapshot: configure threshold size

Test: th
Change-Id: Iba59fdc3e1188dd343314d129806d2c4c94aa8c5
---
 .../user-space-merge/snapuserd_verify.cpp         | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_verify.cpp b/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_verify.cpp
index 681734080..957c6a8a7 100644
--- a/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_verify.cpp
+++ b/fs_mgr/libsnapshot/snapuserd/user-space-merge/snapuserd_verify.cpp
@@ -20,6 +20,7 @@
 #include <android-base/scopeguard.h>
 #include <android-base/strings.h>
 
+#include "android-base/properties.h"
 #include "snapuserd_core.h"
 
 namespace android {
@@ -104,7 +105,9 @@ bool UpdateVerify::VerifyBlocks(const std::string& partition_name,
     }
 
     loff_t file_offset = offset;
-    const uint64_t read_sz = kBlockSizeVerify;
+    auto verify_block_size = android::base::GetUintProperty<uint>("ro.virtual_ab.verify_block_size",
+                                                                  kBlockSizeVerify);
+    const uint64_t read_sz = verify_block_size;
 
     void* addr;
     ssize_t page_size = getpagesize();
@@ -130,7 +133,7 @@ bool UpdateVerify::VerifyBlocks(const std::string& partition_name,
         }
 
         bytes_read += to_read;
-        file_offset += (skip_blocks * kBlockSizeVerify);
+        file_offset += (skip_blocks * verify_block_size);
         if (file_offset >= dev_sz) {
             break;
         }
@@ -184,7 +187,9 @@ bool UpdateVerify::VerifyPartition(const std::string& partition_name,
      * latency.
      */
     int num_threads = kMinThreadsToVerify;
-    if (dev_sz > kThresholdSize) {
+    auto verify_threshold_size = android::base::GetUintProperty<uint>(
+            "ro.virtual_ab.verify_threshold_size", kThresholdSize);
+    if (dev_sz > verify_threshold_size) {
         num_threads = kMaxThreadsToVerify;
     }
 
@@ -192,11 +197,13 @@ bool UpdateVerify::VerifyPartition(const std::string& partition_name,
     off_t start_offset = 0;
     const int skip_blocks = num_threads;
 
+    auto verify_block_size =
+            android::base::GetUintProperty("ro.virtual_ab.verify_block_size", kBlockSizeVerify);
     while (num_threads) {
         threads.emplace_back(std::async(std::launch::async, &UpdateVerify::VerifyBlocks, this,
                                         partition_name, dm_block_device, start_offset, skip_blocks,
                                         dev_sz));
-        start_offset += kBlockSizeVerify;
+        start_offset += verify_block_size;
         num_threads -= 1;
         if (start_offset >= dev_sz) {
             break;