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/*
* Copyright (C) 2011, 2012 Apple Inc. All Rights Reserved.
* Copyright (C) 2014 Raspberry Pi Foundation. All Rights Reserved.
* Copyright (C) 2018 Igalia S.L.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include <wtf/MemoryPressureHandler.h>
#include <malloc.h>
#include <unistd.h>
#include <wtf/Logging.h>
#include <wtf/MainThread.h>
#include <wtf/MemoryFootprint.h>
#include <wtf/text/WTFString.h>
#if OS(LINUX)
#include <wtf/linux/CurrentProcessMemoryStatus.h>
#elif OS(FREEBSD)
#include <sys/sysctl.h>
#include <sys/types.h>
#include <sys/user.h>
#elif OS(QNX)
#include <fcntl.h>
#include <sys/procfs.h>
#endif
namespace WTF {
// Disable memory event reception for a minimum of s_minimumHoldOffTime
// seconds after receiving an event. Don't let events fire any sooner than
// s_holdOffMultiplier times the last cleanup processing time. Effectively
// this is 1 / s_holdOffMultiplier percent of the time.
// If after releasing the memory we don't free at least s_minimumBytesFreedToUseMinimumHoldOffTime,
// we wait longer to try again (s_maximumHoldOffTime).
// These value seems reasonable and testing verifies that it throttles frequent
// low memory events, greatly reducing CPU usage.
static const Seconds s_minimumHoldOffTime { 5_s };
static const Seconds s_maximumHoldOffTime { 30_s };
static const size_t s_minimumBytesFreedToUseMinimumHoldOffTime = 1 * MB;
static const unsigned s_holdOffMultiplier = 20;
void MemoryPressureHandler::triggerMemoryPressureEvent(bool isCritical)
{
if (!m_installed)
return;
if (ReliefLogger::loggingEnabled())
LOG(MemoryPressure, "Got memory pressure notification (%s)", isCritical ? "critical" : "non-critical");
setMemoryPressureStatus(SystemMemoryPressureStatus::Critical);
ensureOnMainThread([this, isCritical] {
respondToMemoryPressure(isCritical ? Critical::Yes : Critical::No);
});
if (ReliefLogger::loggingEnabled() && isUnderMemoryPressure())
LOG(MemoryPressure, "System is no longer under memory pressure.");
setMemoryPressureStatus(SystemMemoryPressureStatus::Normal);
}
void MemoryPressureHandler::install()
{
if (m_installed || m_holdOffTimer.isActive())
return;
m_installed = true;
}
void MemoryPressureHandler::uninstall()
{
if (!m_installed)
return;
m_holdOffTimer.stop();
m_installed = false;
}
void MemoryPressureHandler::holdOffTimerFired()
{
install();
}
void MemoryPressureHandler::holdOff(Seconds seconds)
{
m_holdOffTimer.startOneShot(seconds);
}
static size_t processMemoryUsage()
{
#if OS(LINUX)
ProcessMemoryStatus memoryStatus;
currentProcessMemoryStatus(memoryStatus);
return (memoryStatus.resident - memoryStatus.shared);
#elif OS(FREEBSD)
static size_t pageSize = sysconf(_SC_PAGE_SIZE);
struct kinfo_proc info;
size_t infolen = sizeof(info);
int mib[4];
mib[0] = CTL_KERN;
mib[1] = KERN_PROC;
mib[2] = KERN_PROC_PID;
mib[3] = getpid();
if (sysctl(mib, 4, &info, &infolen, nullptr, 0))
return 0;
return static_cast<size_t>(info.ki_rssize - info.ki_tsize) * pageSize;
#elif OS(QNX)
int fd = open("/proc/self/ctl", O_RDONLY);
if (fd == -1)
return 0;
procfs_asinfo info;
int rc = devctl(fd, DCMD_PROC_ASINFO, &info, sizeof(info), nullptr);
close(fd);
if (rc)
return 0;
return static_cast<size_t>(info.rss);
#else
#error "Missing a platform specific way of determining the memory usage"
#endif
}
void MemoryPressureHandler::respondToMemoryPressure(Critical critical, Synchronous synchronous)
{
uninstall();
MonotonicTime startTime = MonotonicTime::now();
int64_t processMemory = processMemoryUsage();
releaseMemory(critical, synchronous);
int64_t bytesFreed = processMemory - processMemoryUsage();
Seconds holdOffTime = s_maximumHoldOffTime;
if (bytesFreed > 0 && static_cast<size_t>(bytesFreed) >= s_minimumBytesFreedToUseMinimumHoldOffTime)
holdOffTime = (MonotonicTime::now() - startTime) * s_holdOffMultiplier;
holdOff(std::max(holdOffTime, s_minimumHoldOffTime));
}
void MemoryPressureHandler::platformReleaseMemory(Critical)
{
#if HAVE(MALLOC_TRIM)
malloc_trim(0);
#endif
}
std::optional<MemoryPressureHandler::ReliefLogger::MemoryUsage> MemoryPressureHandler::ReliefLogger::platformMemoryUsage()
{
return MemoryUsage {processMemoryUsage(), memoryFootprint()};
}
} // namespace WTF
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