Optimize memory usage in incidentd
EncodedBuffer is used a lot in incidentd. EncodedBuffer uses malloc
internally to acquire memory. Frequently creating and destroying
EncodedBuffer creates memory fragmentation, leading to high memory
usage after taking an incident report.
Also fixes a few other places with lots of malloc/free operations.
This change:
* Creates a pool of EncodedBuffer in incidentd. The saving is
significant. It reduces EncodedBuffer creation from 3 per section to
3 per report.
* Replaces malloc with mmap inside EncodedBuffer. mmap is guaranteed
to be mem page aligned, so there will be no mem fragmentation after
destroying EncodedBuffer.
* Replaces new with mmap inside TombstoneSection
* Forks a process to execute LogSection, because liblog malloc & free
significant amount of memory
Result:
PSS before taking a report: 1295 KB
PSS after taking a report: 1336 KB
Bug: 150311553
Test: heapprofd
Change-Id: I83bd9c969b751c80b2f42747020799bd85d8aae6
diff --git a/cmds/incidentd/src/incidentd_util.cpp b/cmds/incidentd/src/incidentd_util.cpp
index 2649fb9..150ab99 100644
--- a/cmds/incidentd/src/incidentd_util.cpp
+++ b/cmds/incidentd/src/incidentd_util.cpp
@@ -18,6 +18,7 @@
#include "incidentd_util.h"
+#include <android/util/EncodedBuffer.h>
#include <fcntl.h>
#include <sys/prctl.h>
#include <wait.h>
@@ -28,8 +29,6 @@
namespace os {
namespace incidentd {
-using namespace android::base;
-
const Privacy* get_privacy_of_section(int id) {
int l = 0;
int r = PRIVACY_POLICY_COUNT - 1;
@@ -48,6 +47,30 @@
return NULL;
}
+std::vector<sp<EncodedBuffer>> gBufferPool;
+std::mutex gBufferPoolLock;
+
+sp<EncodedBuffer> get_buffer_from_pool() {
+ std::scoped_lock<std::mutex> lock(gBufferPoolLock);
+ if (gBufferPool.size() == 0) {
+ return new EncodedBuffer();
+ }
+ sp<EncodedBuffer> buffer = gBufferPool.back();
+ gBufferPool.pop_back();
+ return buffer;
+}
+
+void return_buffer_to_pool(sp<EncodedBuffer> buffer) {
+ buffer->clear();
+ std::scoped_lock<std::mutex> lock(gBufferPoolLock);
+ gBufferPool.push_back(buffer);
+}
+
+void clear_buffer_pool() {
+ std::scoped_lock<std::mutex> lock(gBufferPoolLock);
+ gBufferPool.clear();
+}
+
// ================================================================================
Fpipe::Fpipe() : mRead(), mWrite() {}
@@ -84,7 +107,7 @@
status = &dummy_status;
}
*status = 0;
- pid_t pid = fork();
+ pid_t pid = vfork();
if (pid < 0) {
*status = -errno;
return -1;