File dirty.h

Defines

CLEAR_REFS

PAGEMAP

PAGEMAP_ENTRY_BYTES

PAGEMAP_SOFT_DIRTY

namespace faabric

namespace util

class DirtyTracker

Subclassed by faabric::util::NoneDirtyTracker, faabric::util::SegfaultDirtyTracker, faabric::util::SoftPTEDirtyTracker, faabric::util::UffdDirtyTracker

Public Functions

inline DirtyTracker(const std::string &modeIn)

virtual void clearAll() = 0

virtual std::string getType() = 0

virtual void startTracking(std::span<uint8_t> region) = 0

virtual void stopTracking(std::span<uint8_t> region) = 0

virtual std::vector<char> getDirtyPages(std::span<uint8_t> region) = 0

virtual void startThreadLocalTracking(std::span<uint8_t> region) = 0

virtual void stopThreadLocalTracking(std::span<uint8_t> region) = 0

virtual std::vector<char> getThreadLocalDirtyPages(std::span<uint8_t> region) = 0

virtual std::vector<char> getBothDirtyPages(std::span<uint8_t> region) = 0

Protected Attributes

const std::string mode

class NoneDirtyTracker : public faabric::util::DirtyTracker

Public Functions

NoneDirtyTracker(const std::string &modeIn)

virtual void clearAll() override

inline virtual std::string getType() override

virtual void startTracking(std::span<uint8_t> region) override

virtual void stopTracking(std::span<uint8_t> region) override

virtual std::vector<char> getDirtyPages(std::span<uint8_t> region) override

virtual void startThreadLocalTracking(std::span<uint8_t> region) override

virtual void stopThreadLocalTracking(std::span<uint8_t> region) override

virtual std::vector<char> getThreadLocalDirtyPages(std::span<uint8_t> region) override

virtual std::vector<char> getBothDirtyPages(std::span<uint8_t> region) override

Private Members

std::vector<char> dirtyPages

class SegfaultDirtyTracker : public faabric::util::DirtyTracker

Public Functions

SegfaultDirtyTracker(const std::string &modeIn)

virtual void clearAll() override

inline virtual std::string getType() override

virtual void startTracking(std::span<uint8_t> region) override

virtual void stopTracking(std::span<uint8_t> region) override

virtual std::vector<char> getDirtyPages(std::span<uint8_t> region) override

virtual void startThreadLocalTracking(std::span<uint8_t> region) override

virtual void stopThreadLocalTracking(std::span<uint8_t> region) override

virtual std::vector<char> getThreadLocalDirtyPages(std::span<uint8_t> region) override

virtual std::vector<char> getBothDirtyPages(std::span<uint8_t> region) override

Public Static Functions

static void handler(int sig, siginfo_t *info, void *ucontext) noexcept

class SoftPTEDirtyTracker : public faabric::util::DirtyTracker

Public Functions

SoftPTEDirtyTracker(const std::string &modeIn)

~SoftPTEDirtyTracker()

virtual void clearAll() override

inline virtual std::string getType() override

virtual void startTracking(std::span<uint8_t> region) override

virtual void stopTracking(std::span<uint8_t> region) override

virtual std::vector<char> getDirtyPages(std::span<uint8_t> region) override

virtual void startThreadLocalTracking(std::span<uint8_t> region) override

virtual void stopThreadLocalTracking(std::span<uint8_t> region) override

virtual std::vector<char> getThreadLocalDirtyPages(std::span<uint8_t> region) override

virtual std::vector<char> getBothDirtyPages(std::span<uint8_t> region) override

Private Functions

void resetPTEs()

Private Members

FILE *clearRefsFile = nullptr

FILE *pagemapFile = nullptr

class UffdDirtyTracker : public faabric::util::DirtyTracker

#include <dirty.h>

Dirty tracking implementation using userfaultfd to write-protect pages, then handle the resulting userspace events when they are written to.

The dirty tracking mode can be one of four options:

• uffd - uses the SIGBUS handler to catch events triggered by accessing missing pages in demand-zero paged memory.

• uffd-wp - same as uffd but adds write-protected events to catch subsequent writes to write-protected pages.

• uffd-thread - same as uffd, but using a background event thread to handle events. This has the benefit of distinguishing between read and write missing page events.

• uffd-thread-wp - same as uffd-thread, but adds write-protected events.

See the docs for more info on these different approaches: https://www.kernel.org/doc/html/latest/admin-guide/mm/userfaultfd.html

Public Functions

UffdDirtyTracker(const std::string &modeIn)

~UffdDirtyTracker()

virtual void clearAll() override

inline virtual std::string getType() override

virtual void startTracking(std::span<uint8_t> region) override

virtual void stopTracking(std::span<uint8_t> region) override

virtual std::vector<char> getDirtyPages(std::span<uint8_t> region) override

virtual void startThreadLocalTracking(std::span<uint8_t> region) override

virtual void stopThreadLocalTracking(std::span<uint8_t> region) override

virtual std::vector<char> getThreadLocalDirtyPages(std::span<uint8_t> region) override

virtual std::vector<char> getBothDirtyPages(std::span<uint8_t> region) override

Public Static Functions

static void sigbusHandler(int sig, siginfo_t *info, void *ucontext) noexcept

Private Members

bool writeProtect = false

bool sigbus = false

Private Static Functions

static void initUffd()

static void stopUffd()

static void registerRegion(std::span<uint8_t> region)

static void writeProtectRegion(std::span<uint8_t> region)

static void removeWriteProtect(std::span<uint8_t> region, bool throwEx)

static bool zeroRegion(std::span<uint8_t> region)

static void deregisterRegion(std::span<uint8_t> region)

static void eventThreadEntrypoint()