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-rw-r--r--xpcom/base/PHCManager.cpp89
1 files changed, 89 insertions, 0 deletions
diff --git a/xpcom/base/PHCManager.cpp b/xpcom/base/PHCManager.cpp
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+++ b/xpcom/base/PHCManager.cpp
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "PHCManager.h"
+
+#include "PHC.h"
+#include "mozilla/Literals.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/StaticPrefs_memory.h"
+#include "mozilla/Telemetry.h"
+#include "prsystem.h"
+
+namespace mozilla {
+
+using namespace phc;
+
+static const char kPHCEnabledPref[] = "memory.phc.enabled";
+static const char kPHCMinRamMBPref[] = "memory.phc.min_ram_mb";
+static const char kPHCAvgDelayFirst[] = "memory.phc.avg_delay.first";
+static const char kPHCAvgDelayNormal[] = "memory.phc.avg_delay.normal";
+static const char kPHCAvgDelayPageRuse[] = "memory.phc.avg_delay.page_reuse";
+
+// True if PHC has ever been enabled for this process.
+static bool sWasPHCEnabled = false;
+
+static void UpdatePHCState() {
+ size_t mem_size = PR_GetPhysicalMemorySize() / (1_MiB);
+ size_t min_mem_size = StaticPrefs::memory_phc_min_ram_mb();
+
+ // Only enable PHC if there are at least 8GB of ram. Note that we use
+ // 1000 bytes per kilobyte rather than 1024. Some 8GB machines will have
+ // slightly lower actual RAM available after some hardware devices
+ // reserve some.
+ if (StaticPrefs::memory_phc_enabled() && mem_size >= min_mem_size) {
+ // Set PHC probablities before enabling PHC so that the first allocation
+ // delay gets used.
+ SetPHCProbabilities(StaticPrefs::memory_phc_avg_delay_first(),
+ StaticPrefs::memory_phc_avg_delay_normal(),
+ StaticPrefs::memory_phc_avg_delay_page_reuse());
+
+ SetPHCState(Enabled);
+ sWasPHCEnabled = true;
+ } else {
+ SetPHCState(OnlyFree);
+ }
+}
+
+static void PrefChangeCallback(const char* aPrefName, void* aNull) {
+ MOZ_ASSERT((0 == strcmp(aPrefName, kPHCEnabledPref)) ||
+ (0 == strcmp(aPrefName, kPHCMinRamMBPref)) ||
+ (0 == strcmp(aPrefName, kPHCAvgDelayFirst)) ||
+ (0 == strcmp(aPrefName, kPHCAvgDelayNormal)) ||
+ (0 == strcmp(aPrefName, kPHCAvgDelayPageRuse)));
+
+ UpdatePHCState();
+}
+
+void InitPHCState() {
+ Preferences::RegisterCallback(PrefChangeCallback, kPHCEnabledPref);
+ Preferences::RegisterCallback(PrefChangeCallback, kPHCMinRamMBPref);
+ Preferences::RegisterCallback(PrefChangeCallback, kPHCAvgDelayFirst);
+ Preferences::RegisterCallback(PrefChangeCallback, kPHCAvgDelayNormal);
+ Preferences::RegisterCallback(PrefChangeCallback, kPHCAvgDelayPageRuse);
+ UpdatePHCState();
+}
+
+void ReportPHCTelemetry() {
+ if (!sWasPHCEnabled) {
+ return;
+ }
+
+ MemoryUsage usage;
+ PHCMemoryUsage(usage);
+
+ Accumulate(Telemetry::MEMORY_PHC_SLOP, usage.mFragmentationBytes);
+
+ PHCStats stats;
+ GetPHCStats(stats);
+
+ Accumulate(Telemetry::MEMORY_PHC_SLOTS_ALLOCATED, stats.mSlotsAllocated);
+ Accumulate(Telemetry::MEMORY_PHC_SLOTS_FREED, stats.mSlotsFreed);
+ // There are also slots that are unused (neither free nor allocated) they
+ // can be calculated by knowing the total number of slots.
+}
+
+}; // namespace mozilla