From b2679847464ae30f88ac36d8717d1a8e05328653 Mon Sep 17 00:00:00 2001
From: abrand <anton.brand@ubisoft.com>
Date: Fri, 19 Dec 2025 16:10:17 -0500
Subject: [PATCH] fix hyperthreading cores reservation

---
 rqd/rqd/rqcore.py    | 21 ++++++++++------
 rqd/rqd/rqmachine.py | 60 ++++++++++++++++++++++++++++++--------------
 2 files changed, 55 insertions(+), 26 deletions(-)

diff --git a/rqd/rqd/rqcore.py b/rqd/rqd/rqcore.py
index e60d49365..89e138296 100644
--- a/rqd/rqd/rqcore.py
+++ b/rqd/rqd/rqcore.py
@@ -423,17 +423,24 @@ def launchFrame(self, runFrame):
 
         # See if all requested cores are available
         with self.__threadLock:
-            # pylint: disable=no-member
-            if self.cores.idle_cores < runFrame.num_cores:
-                err = "Not launching, insufficient idle cores"
-                log.critical(err)
-                raise rqd.rqexceptions.CoreReservationFailureException(err)
-            # pylint: enable=no-member
-
+            # For hyperthreading workloads, check HT core availability first
+            # as it uses a different counting mechanism than idle_cores
             if runFrame.environment.get('CUE_THREADABLE') == '1':
+                if not self.machine.canReserveHT(runFrame.num_cores):
+                    err = "Not launching, insufficient hyperthreading cores available"
+                    log.critical(err)
+                    raise rqd.rqexceptions.CoreReservationFailureException(err)
                 reserveHT = self.machine.reserveHT(runFrame.num_cores)
                 if reserveHT:
                     runFrame.attributes['CPU_LIST'] = reserveHT
+            else:
+                # Only check idle cores for non-hyperthreading workloads
+                # pylint: disable=no-member
+                if self.cores.idle_cores < runFrame.num_cores:
+                    err = "Not launching, insufficient idle cores"
+                    log.critical(err)
+                    raise rqd.rqexceptions.CoreReservationFailureException(err)
+                # pylint: enable=no-member
 
             if runFrame.num_gpus:
                 reserveGpus = self.machine.reserveGpus(runFrame.num_gpus)
diff --git a/rqd/rqd/rqmachine.py b/rqd/rqd/rqmachine.py
index 610df78ee..2968d45a0 100644
--- a/rqd/rqd/rqmachine.py
+++ b/rqd/rqd/rqmachine.py
@@ -936,7 +936,41 @@ def setupGpu(self):
         """ Setup rqd for Gpus """
         self.__gpusets = set(range(self.getGpuCount()))
 
-    def reserveHT(self, frameCores):
+    def _getAvailableHTCores(self):
+        """Get available hyperthreading cores information
+        @rtype:  tuple
+        @return: (avail_cores_dict, avail_cores_count) where avail_cores_dict
+                 maps physid -> set(coreid) and avail_cores_count is the total count
+        """
+        avail_cores = {}
+        avail_cores_count = 0
+        reserved_cores = self.__coreInfo.reserved_cores
+
+        for physid, cores in self.__procs_by_physid_and_coreid.items():
+            for coreid in cores.keys():
+                if int(physid) in reserved_cores and \
+                        int(coreid) in reserved_cores[int(physid)].coreid:
+                    continue
+                avail_cores.setdefault(physid, set()).add(coreid)
+                avail_cores_count += 1
+
+        return avail_cores, avail_cores_count
+
+    def canReserveHT(self, frameCores: int):
+        """Check if hyperthreading cores can be reserved without actually reserving them
+        @type   frameCores: int
+        @param  frameCores: The total physical cores required by the frame.
+        @rtype:  bool
+        @return: True if cores can be reserved, False otherwise
+        """
+        if frameCores % 100:
+            return False
+
+        _, avail_cores_count = self._getAvailableHTCores()
+        remaining_cores = frameCores / 100
+        return avail_cores_count >= remaining_cores
+
+    def reserveHT(self, frameCores: int):
         """ Reserve cores for use by taskset
         taskset -c 0,1,8,9 COMMAND
         Not thread save, use with locking.
@@ -951,21 +985,8 @@ def reserveHT(self, frameCores):
             return None
         log.info('Taskset: Requesting reserve of %d', (frameCores // 100))
 
-        # Look for the most idle physical cpu.
-        # Prefer to assign cores from the same physical cpu.
-        # Spread different frames around on different physical cpus.
-        avail_cores = {}
-        avail_cores_count = 0
-        reserved_cores = self.__coreInfo.reserved_cores
-
-        for physid, cores in self.__procs_by_physid_and_coreid.items():
-            for coreid in cores.keys():
-                if int(physid) in reserved_cores and \
-                        int(coreid) in reserved_cores[int(physid)].coreid:
-                    continue
-                avail_cores.setdefault(physid, set()).add(coreid)
-                avail_cores_count += 1
-
+        # Get available cores using factored method
+        avail_cores, avail_cores_count = self._getAvailableHTCores()
         remaining_cores = frameCores / 100
 
         if avail_cores_count < remaining_cores:
@@ -976,6 +997,7 @@ def reserveHT(self, frameCores):
             raise rqd.rqexceptions.CoreReservationFailureException(err)
 
         tasksets = []
+        reserved_cores = self.__coreInfo.reserved_cores
 
         for physid, cores in sorted(
                 avail_cores.items(),
@@ -997,9 +1019,9 @@ def reserveHT(self, frameCores):
             if remaining_cores == 0:
                 break
 
-        log.warning('Taskset: Reserving procs - %s', ','.join(tasksets))
-
-        return ','.join(tasksets)
+        joined_tasksets = ','.join(sorted(tasksets, key=int))
+        log.warning('Taskset: Reserving procs - %s', joined_tasksets)
+        return joined_tasksets
 
     # pylint: disable=inconsistent-return-statements
     def releaseHT(self, reservedHT):