intel/compute-runtime
1
0
Fork 0
mirror of https://github.com/intel/compute-runtime.git synced 2026-01-11 16:45:25 +08:00
Code Issues Packages Projects Releases Wiki Activity

Broadcast signal to all threads while handling USM pagefault

Browse Source 
Related-To: NEO-4721

Change-Id: I77185f8db2576f626c1b6b5615ab5d8f9b22076f
Signed-off-by: Lukasz Jobczyk <lukasz.jobczyk@intel.com>
This commit is contained in:
Lukasz Jobczyk
2020-07-06 13:09:12 +02:00
committed by sys_ocldev
parent e3ccf19b47
commit 5739d526c4
8 changed files with 122 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

63
shared/source/page_fault_manager/linux/cpu_page_fault_manager_linux.cpp
View File

@@ -9,7 +9,11 @@
#include "shared/source/helpers/debug_helpers.h"
#include <dirent.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>
namespace NEO {
std::unique_ptr<PageFaultManager> PageFaultManager::create() {
@@ -20,7 +24,9 @@ std::function<void(int signal, siginfo_t *info, void *context)> PageFaultManager
PageFaultManagerLinux::PageFaultManagerLinux() {
pageFaultHandler = [&](int signal, siginfo_t *info, void *context) {
if (!this->verifyPageFault(info->si_addr)) {
if (signal == SIGUSR1) {
this->waitForCopy();
} else if (!this->verifyPageFault(info->si_addr)) {
callPreviousHandler(signal, info, context);
}
};
@@ -28,13 +34,20 @@ PageFaultManagerLinux::PageFaultManagerLinux() {
struct sigaction pageFaultManagerHandler = {};
pageFaultManagerHandler.sa_flags = SA_SIGINFO;
pageFaultManagerHandler.sa_sigaction = pageFaultHandlerWrapper;
auto retVal = sigaction(SIGSEGV, &pageFaultManagerHandler, &previousHandler);
auto retVal = sigaction(SIGSEGV, &pageFaultManagerHandler, &previousPageFaultHandler);
UNRECOVERABLE_IF(retVal != 0);
retVal = sigaction(SIGUSR1, &pageFaultManagerHandler, &previousUserSignalHandler);
UNRECOVERABLE_IF(retVal != 0);
}
PageFaultManagerLinux::~PageFaultManagerLinux() {
if (!previousHandlerRestored) {
auto retVal = sigaction(SIGSEGV, &previousHandler, nullptr);
auto retVal = sigaction(SIGSEGV, &previousPageFaultHandler, nullptr);
UNRECOVERABLE_IF(retVal != 0);
retVal = sigaction(SIGUSR1, &previousUserSignalHandler, nullptr);
UNRECOVERABLE_IF(retVal != 0);
}
}
@@ -54,18 +67,50 @@ void PageFaultManagerLinux::protectCPUMemoryAccess(void *ptr, size_t size) {
}
void PageFaultManagerLinux::callPreviousHandler(int signal, siginfo_t *info, void *context) {
if (previousHandler.sa_flags & SA_SIGINFO) {
previousHandler.sa_sigaction(signal, info, context);
if (previousPageFaultHandler.sa_flags & SA_SIGINFO) {
previousPageFaultHandler.sa_sigaction(signal, info, context);
} else {
if (previousHandler.sa_handler == SIG_DFL) {
auto retVal = sigaction(SIGSEGV, &previousHandler, nullptr);
if (previousPageFaultHandler.sa_handler == SIG_DFL) {
auto retVal = sigaction(SIGSEGV, &previousPageFaultHandler, nullptr);
UNRECOVERABLE_IF(retVal != 0);
previousHandlerRestored = true;
} else if (previousHandler.sa_handler == SIG_IGN) {
} else if (previousPageFaultHandler.sa_handler == SIG_IGN) {
return;
} else {
previousHandler.sa_handler(signal);
previousPageFaultHandler.sa_handler(signal);
}
}
}
/* This function is a WA for USM issue in multithreaded environment
While handling page fault, before copy starts, user signal (SIGUSR1)
is broadcasted to ensure that every thread received signal and is
stucked on PageFaultHandler's mutex before copy from GPU to CPU proceeds. */
void PageFaultManagerLinux::broadcastWaitSignal() {
auto selfThreadId = syscall(__NR_gettid);
auto procDir = opendir("/proc/self/task");
UNRECOVERABLE_IF(!procDir);
struct dirent *dirEntry;
while ((dirEntry = readdir(procDir)) != NULL) {
if (dirEntry->d_name[0] == '.') {
continue;
}
int threadId = atoi(dirEntry->d_name);
if (threadId == selfThreadId) {
continue;
}
sendSignalToThread(threadId);
}
closedir(procDir);
}
void PageFaultManagerLinux::sendSignalToThread(int threadId) {
syscall(SYS_tkill, threadId, SIGUSR1);
}
} // namespace NEO

7
shared/source/page_fault_manager/linux/cpu_page_fault_manager_linux.h
View File

@@ -24,10 +24,15 @@ class PageFaultManagerLinux : public PageFaultManager {
void allowCPUMemoryAccess(void *ptr, size_t size) override;
void protectCPUMemoryAccess(void *ptr, size_t size) override;
void broadcastWaitSignal() override;
MOCKABLE_VIRTUAL void sendSignalToThread(int threadId);
void callPreviousHandler(int signal, siginfo_t *info, void *context);
bool previousHandlerRestored = false;
static std::function<void(int signal, siginfo_t *info, void *context)> pageFaultHandler;
struct sigaction previousHandler = {};
struct sigaction previousPageFaultHandler = {};
struct sigaction previousUserSignalHandler = {};
};
} // namespace NEO