// true if setting the affinity was successful, false otherwise.
bool GCToOSInterface::SetThreadAffinity(uint16_t procNo)
{
-#if HAVE_PTHREAD_GETAFFINITY_NP
+#if HAVE_SCHED_SETAFFINITY || HAVE_PTHREAD_SETAFFINITY_NP
cpu_set_t cpuSet;
CPU_ZERO(&cpuSet);
CPU_SET((int)procNo, &cpuSet);
+ // Snap's default strict confinement does not allow sched_setaffinity(<nonzeroPid>, ...) without manually connecting the
+ // process-control plug. sched_setaffinity(<currentThreadPid>, ...) is also currently not allowed, only
+ // sched_setaffinity(0, ...). pthread_setaffinity_np(pthread_self(), ...) seems to call
+ // sched_setaffinity(<currentThreadPid>, ...) in at least one implementation, and does not work. To work around those
+ // issues, use sched_setaffinity(0, ...) if available and only otherwise fall back to pthread_setaffinity_np(). See the
+ // following for more information:
+ // - https://github.com/dotnet/runtime/pull/38795
+ // - https://github.com/dotnet/runtime/issues/1634
+ // - https://forum.snapcraft.io/t/requesting-autoconnect-for-interfaces-in-pigmeat-process-control-home/17987/13
+#if HAVE_SCHED_SETAFFINITY
+ int st = sched_setaffinity(0, sizeof(cpu_set_t), &cpuSet);
+#else
int st = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuSet);
+#endif
return (st == 0);
-#else // HAVE_PTHREAD_GETAFFINITY_NP
+#else // !(HAVE_SCHED_SETAFFINITY || HAVE_PTHREAD_SETAFFINITY_NP)
// There is no API to manage thread affinity, so let's ignore the request
return false;
-#endif // HAVE_PTHREAD_GETAFFINITY_NP
+#endif // HAVE_SCHED_SETAFFINITY || HAVE_PTHREAD_SETAFFINITY_NP
}
// Boosts the calling thread's thread priority to a level higher than the default
storedErrno = errno;
#endif // PTHREAD_CREATE_MODIFIES_ERRNO
-#if HAVE_PTHREAD_ATTR_SETAFFINITY_NP && HAVE_SCHED_GETAFFINITY
- {
- // Threads inherit their parent's affinity mask on Linux. This is not desired, so we reset
- // the current thread's affinity mask to the mask of the current process.
- cpu_set_t cpuSet;
- CPU_ZERO(&cpuSet);
-
- int st = sched_getaffinity(gPID, sizeof(cpu_set_t), &cpuSet);
- if (st != 0)
- {
- ASSERT("sched_getaffinity failed!\n");
- // the sched_getaffinity should never fail for getting affinity of the current process
- palError = ERROR_INTERNAL_ERROR;
- goto EXIT;
- }
-
- st = pthread_attr_setaffinity_np(&pthreadAttr, sizeof(cpu_set_t), &cpuSet);
- if (st != 0)
- {
- if (st == ENOMEM)
- {
- palError = ERROR_NOT_ENOUGH_MEMORY;
- }
- else
- {
- ASSERT("pthread_attr_setaffinity_np failed!\n");
- // The pthread_attr_setaffinity_np should never fail except of OOM when
- // passed the mask extracted using sched_getaffinity.
- palError = ERROR_INTERNAL_ERROR;
- }
- goto EXIT;
- }
- }
-#endif // HAVE_PTHREAD_GETAFFINITY_NP && HAVE_SCHED_GETAFFINITY
-
iError = pthread_create(&pthread, &pthreadAttr, CPalThread::ThreadEntry, pNewThread);
#if PTHREAD_CREATE_MODIFIES_ERRNO
PTHREAD_START_ROUTINE pfnStartRoutine;
LPVOID pvPar;
DWORD retValue;
+#if HAVE_SCHED_GETAFFINITY && HAVE_SCHED_SETAFFINITY
+ cpu_set_t cpuSet;
+ int st;
+#endif
pThread = reinterpret_cast<CPalThread*>(pvParam);
goto fail;
}
+#if HAVE_SCHED_GETAFFINITY && HAVE_SCHED_SETAFFINITY
+ // Threads inherit their parent's affinity mask on Linux. This is not desired, so we reset
+ // the current thread's affinity mask to the mask of the current process.
+ //
+ // Typically, we would use pthread_attr_setaffinity_np() and have pthread_create() create the thread with the specified
+ // affinity. At least one implementation of pthread_create() following a pthread_attr_setaffinity_np() calls
+ // sched_setaffinity(<newThreadPid>, ...), which is not allowed under Snap's default strict confinement without manually
+ // connecting the process-control plug. To work around that, have the thread set the affinity after it starts.
+ // sched_setaffinity(<currentThreadPid>, ...) is also currently not allowed, only sched_setaffinity(0, ...).
+ // pthread_setaffinity_np(pthread_self(), ...) seems to call sched_setaffinity(<currentThreadPid>, ...) in at least one
+ // implementation, and does not work. Use sched_setaffinity(0, ...) instead. See the following for more information:
+ // - https://github.com/dotnet/runtime/pull/38795
+ // - https://github.com/dotnet/runtime/issues/1634
+ // - https://forum.snapcraft.io/t/requesting-autoconnect-for-interfaces-in-pigmeat-process-control-home/17987/13
+
+ CPU_ZERO(&cpuSet);
+
+ st = sched_getaffinity(gPID, sizeof(cpu_set_t), &cpuSet);
+ if (st != 0)
+ {
+ ASSERT("sched_getaffinity failed!\n");
+ // The sched_getaffinity should never fail for getting affinity of the current process
+ palError = ERROR_INTERNAL_ERROR;
+ goto fail;
+ }
+
+ st = sched_setaffinity(0, sizeof(cpu_set_t), &cpuSet);
+ if (st != 0)
+ {
+ ASSERT("sched_setaffinity failed!\n");
+ // The sched_setaffinity should never fail when passed the mask extracted using sched_getaffinity
+ palError = ERROR_INTERNAL_ERROR;
+ goto fail;
+ }
+#endif // HAVE_SCHED_GETAFFINITY && HAVE_SCHED_SETAFFINITY
+
#if !HAVE_MACH_EXCEPTIONS
if (!pThread->EnsureSignalAlternateStack())
{
PALAPI
PAL_SetCurrentThreadAffinity(WORD procNo)
{
-#if HAVE_PTHREAD_GETAFFINITY_NP
+#if HAVE_SCHED_SETAFFINITY || HAVE_PTHREAD_SETAFFINITY_NP
cpu_set_t cpuSet;
CPU_ZERO(&cpuSet);
-
CPU_SET(procNo, &cpuSet);
+
+ // Snap's default strict confinement does not allow sched_setaffinity(<nonzeroPid>, ...) without manually connecting the
+ // process-control plug. sched_setaffinity(<currentThreadPid>, ...) is also currently not allowed, only
+ // sched_setaffinity(0, ...). pthread_setaffinity_np(pthread_self(), ...) seems to call
+ // sched_setaffinity(<currentThreadPid>, ...) in at least one implementation, and does not work. To work around those
+ // issues, use sched_setaffinity(0, ...) if available and only otherwise fall back to pthread_setaffinity_np(). See the
+ // following for more information:
+ // - https://github.com/dotnet/runtime/pull/38795
+ // - https://github.com/dotnet/runtime/issues/1634
+ // - https://forum.snapcraft.io/t/requesting-autoconnect-for-interfaces-in-pigmeat-process-control-home/17987/13
+#if HAVE_SCHED_SETAFFINITY
+ int st = sched_setaffinity(0, sizeof(cpu_set_t), &cpuSet);
+#else
int st = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuSet);
+#endif
return st == 0;
-#else // HAVE_PTHREAD_GETAFFINITY_NP
+#else // !(HAVE_SCHED_SETAFFINITY || HAVE_PTHREAD_SETAFFINITY_NP)
// There is no API to manage thread affinity, so let's ignore the request
return FALSE;
-#endif // HAVE_PTHREAD_GETAFFINITY_NP
+#endif // HAVE_SCHED_SETAFFINITY || HAVE_PTHREAD_SETAFFINITY_NP
}
/*++
projects / platform / upstream / dotnet / runtime.git / commitdiff