MemoryPressureHandler.cpp [plain text]
#include "config.h"
#include "MemoryPressureHandler.h"
#include <wtf/MemoryFootprint.h>
#define LOG_CHANNEL_PREFIX Log
namespace WTF {
#if RELEASE_LOG_DISABLED
WTFLogChannel LogMemoryPressure = { WTFLogChannelOn, "MemoryPressure" };
#else
WTFLogChannel LogMemoryPressure = { WTFLogChannelOn, "MemoryPressure", LOG_CHANNEL_WEBKIT_SUBSYSTEM, OS_LOG_DEFAULT };
#endif
WTF_EXPORT_PRIVATE bool MemoryPressureHandler::ReliefLogger::s_loggingEnabled = false;
MemoryPressureHandler& MemoryPressureHandler::singleton()
{
static NeverDestroyed<MemoryPressureHandler> memoryPressureHandler;
return memoryPressureHandler;
}
MemoryPressureHandler::MemoryPressureHandler()
#if OS(LINUX)
: m_holdOffTimer(RunLoop::main(), this, &MemoryPressureHandler::holdOffTimerFired)
#elif OS(WINDOWS)
: m_windowsMeasurementTimer(RunLoop::main(), this, &MemoryPressureHandler::windowsMeasurementTimerFired)
#endif
{
}
void MemoryPressureHandler::setShouldUsePeriodicMemoryMonitor(bool use)
{
if (!isFastMallocEnabled()) {
return;
}
if (use) {
m_measurementTimer = std::make_unique<RunLoop::Timer<MemoryPressureHandler>>(RunLoop::main(), this, &MemoryPressureHandler::measurementTimerFired);
m_measurementTimer->startRepeating(30);
} else
m_measurementTimer = nullptr;
}
#if !RELEASE_LOG_DISABLED
static const char* toString(MemoryUsagePolicy policy)
{
switch (policy) {
case MemoryUsagePolicy::Unrestricted: return "Unrestricted";
case MemoryUsagePolicy::Conservative: return "Conservative";
case MemoryUsagePolicy::Strict: return "Strict";
}
}
#endif
static size_t thresholdForMemoryKillWithProcessState(WebsamProcessState processState, unsigned tabCount)
{
#if CPU(X86_64) || CPU(ARM64)
size_t baseThreshold;
if (processState == WebsamProcessState::Active)
baseThreshold = 4 * GB;
else
baseThreshold = 2 * GB;
if (tabCount <= 1)
return baseThreshold;
return baseThreshold + (std::min(tabCount - 1, 4u) * 1 * GB);
#else
UNUSED_PARAM(processState);
UNUSED_PARAM(tabCount);
return 3 * GB;
#endif
}
void MemoryPressureHandler::setPageCount(unsigned pageCount)
{
if (singleton().m_pageCount == pageCount)
return;
singleton().m_pageCount = pageCount;
}
size_t MemoryPressureHandler::thresholdForMemoryKill()
{
return thresholdForMemoryKillWithProcessState(m_processState, m_pageCount);
}
static size_t thresholdForPolicy(MemoryUsagePolicy policy)
{
switch (policy) {
case MemoryUsagePolicy::Conservative:
return 1 * GB;
case MemoryUsagePolicy::Strict:
return 1.5 * GB;
case MemoryUsagePolicy::Unrestricted:
default:
ASSERT_NOT_REACHED();
return 0;
}
}
static MemoryUsagePolicy policyForFootprint(size_t footprint)
{
if (footprint >= thresholdForPolicy(MemoryUsagePolicy::Strict))
return MemoryUsagePolicy::Strict;
if (footprint >= thresholdForPolicy(MemoryUsagePolicy::Conservative))
return MemoryUsagePolicy::Conservative;
return MemoryUsagePolicy::Unrestricted;
}
void MemoryPressureHandler::shrinkOrDie()
{
RELEASE_LOG(MemoryPressure, "Process is above the memory kill threshold. Trying to shrink down.");
releaseMemory(Critical::Yes, Synchronous::Yes);
auto footprint = memoryFootprint();
RELEASE_ASSERT(footprint);
RELEASE_LOG(MemoryPressure, "New memory footprint: %lu MB", footprint.value() / MB);
if (footprint.value() < thresholdForMemoryKill()) {
RELEASE_LOG(MemoryPressure, "Shrank below memory kill threshold. Process gets to live.");
setMemoryUsagePolicyBasedOnFootprint(footprint.value());
return;
}
RELEASE_ASSERT(m_memoryKillCallback);
m_memoryKillCallback();
}
void MemoryPressureHandler::setMemoryUsagePolicyBasedOnFootprint(size_t footprint)
{
auto newPolicy = policyForFootprint(footprint);
if (newPolicy == m_memoryUsagePolicy)
return;
RELEASE_LOG(MemoryPressure, "Memory usage policy changed: %s -> %s", toString(m_memoryUsagePolicy), toString(newPolicy));
m_memoryUsagePolicy = newPolicy;
memoryPressureStatusChanged();
}
void MemoryPressureHandler::measurementTimerFired()
{
auto footprint = memoryFootprint();
if (!footprint)
return;
RELEASE_LOG(MemoryPressure, "Current memory footprint: %lu MB", footprint.value() / MB);
if (footprint.value() >= thresholdForMemoryKill()) {
shrinkOrDie();
return;
}
setMemoryUsagePolicyBasedOnFootprint(footprint.value());
switch (m_memoryUsagePolicy) {
case MemoryUsagePolicy::Unrestricted:
break;
case MemoryUsagePolicy::Conservative:
releaseMemory(Critical::No, Synchronous::No);
break;
case MemoryUsagePolicy::Strict:
releaseMemory(Critical::Yes, Synchronous::No);
break;
}
if (processState() == WebsamProcessState::Active && footprint.value() > thresholdForMemoryKillWithProcessState(WebsamProcessState::Inactive, m_pageCount))
doesExceedInactiveLimitWhileActive();
else
doesNotExceedInactiveLimitWhileActive();
}
void MemoryPressureHandler::doesExceedInactiveLimitWhileActive()
{
if (m_hasInvokedDidExceedInactiveLimitWhileActiveCallback)
return;
if (m_didExceedInactiveLimitWhileActiveCallback)
m_didExceedInactiveLimitWhileActiveCallback();
m_hasInvokedDidExceedInactiveLimitWhileActiveCallback = true;
}
void MemoryPressureHandler::doesNotExceedInactiveLimitWhileActive()
{
m_hasInvokedDidExceedInactiveLimitWhileActiveCallback = false;
}
void MemoryPressureHandler::setProcessState(WebsamProcessState state)
{
if (m_processState == state)
return;
m_processState = state;
}
void MemoryPressureHandler::beginSimulatedMemoryPressure()
{
if (m_isSimulatingMemoryPressure)
return;
m_isSimulatingMemoryPressure = true;
memoryPressureStatusChanged();
respondToMemoryPressure(Critical::Yes, Synchronous::Yes);
}
void MemoryPressureHandler::endSimulatedMemoryPressure()
{
if (!m_isSimulatingMemoryPressure)
return;
m_isSimulatingMemoryPressure = false;
memoryPressureStatusChanged();
}
void MemoryPressureHandler::releaseMemory(Critical critical, Synchronous synchronous)
{
if (!m_lowMemoryHandler)
return;
ReliefLogger log("Total");
m_lowMemoryHandler(critical, synchronous);
platformReleaseMemory(critical);
}
void MemoryPressureHandler::setUnderMemoryPressure(bool underMemoryPressure)
{
if (m_underMemoryPressure == underMemoryPressure)
return;
m_underMemoryPressure = underMemoryPressure;
memoryPressureStatusChanged();
}
void MemoryPressureHandler::memoryPressureStatusChanged()
{
if (m_memoryPressureStatusChangedCallback)
m_memoryPressureStatusChangedCallback(isUnderMemoryPressure());
}
void MemoryPressureHandler::ReliefLogger::logMemoryUsageChange()
{
#if !RELEASE_LOG_DISABLED
#define STRING_SPECIFICATION "%{public}s"
#define MEMORYPRESSURE_LOG(...) RELEASE_LOG(MemoryPressure, __VA_ARGS__)
#else
#define STRING_SPECIFICATION "%s"
#define MEMORYPRESSURE_LOG(...) WTFLogAlways(__VA_ARGS__)
#endif
auto currentMemory = platformMemoryUsage();
if (!currentMemory || !m_initialMemory) {
MEMORYPRESSURE_LOG("Memory pressure relief: " STRING_SPECIFICATION ": (Unable to get dirty memory information for process)", m_logString);
return;
}
long residentDiff = currentMemory->resident - m_initialMemory->resident;
long physicalDiff = currentMemory->physical - m_initialMemory->physical;
MEMORYPRESSURE_LOG("Memory pressure relief: " STRING_SPECIFICATION ": res = %zu/%zu/%ld, res+swap = %zu/%zu/%ld",
m_logString,
m_initialMemory->resident, currentMemory->resident, residentDiff,
m_initialMemory->physical, currentMemory->physical, physicalDiff);
}
#if !PLATFORM(COCOA) && !OS(LINUX) && !OS(WINDOWS)
void MemoryPressureHandler::install() { }
void MemoryPressureHandler::uninstall() { }
void MemoryPressureHandler::holdOff(unsigned) { }
void MemoryPressureHandler::respondToMemoryPressure(Critical, Synchronous) { }
void MemoryPressureHandler::platformReleaseMemory(Critical) { }
std::optional<MemoryPressureHandler::ReliefLogger::MemoryUsage> MemoryPressureHandler::ReliefLogger::platformMemoryUsage() { return std::nullopt; }
#endif
#if !OS(WINDOWS)
void MemoryPressureHandler::platformInitialize() { }
#endif
}