From 4e853d8cb6a51b5b96fe61cc2c1891b10f78972c Mon Sep 17 00:00:00 2001
From: Geza Lore <glore@tenstorrent.com>
Date: Fri, 15 May 2026 19:45:39 +0100
Subject: [PATCH] Fix cpu pinning when no 'core id' present in /proc/cpuinfo
 (#7599)

---
 include/verilated_threads.cpp | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/include/verilated_threads.cpp b/include/verilated_threads.cpp
index c6a2afc8c..62ee200be 100644
--- a/include/verilated_threads.cpp
+++ b/include/verilated_threads.cpp
@@ -180,6 +180,20 @@ std::string VlThreadPool::numaAssign(VerilatedContext* contextp) {
     std::set<int> cores;
     {
         int processor = -1;
+        int core = -1;
+
+        const auto finishEntry = [&]() {
+            if (processor == -1) return;
+            // If "core id" is not known, assume all processors are on separate cores with same id.
+            if (core == -1) core = processor;
+            cores.emplace(core);
+            processor_core[processor] = core;
+            core_processors.emplace(core, processor);
+            unassigned_processors.push_back(processor);
+            processor = -1;
+            core = -1;
+        };
+
         while (!is.eof()) {
             std::string line;
             std::getline(is, line);
@@ -187,17 +201,13 @@ std::string VlThreadPool::numaAssign(VerilatedContext* contextp) {
             int number = -1;
             if (pos != std::string::npos) number = atoi(line.c_str() + pos + 1);
             if (line.compare(0, std::strlen("processor"), "processor") == 0) {
+                finishEntry();
                 processor = number;
             } else if (line.compare(0, std::strlen("core id"), "core id") == 0) {
-                const int core = number;
-                // std::cout << "p" << processor << " socket " << socket << " c" << core <<
-                // std::endl;
-                cores.emplace(core);
-                processor_core[processor] = core;
-                core_processors.emplace(core, processor);
-                unassigned_processors.push_back(processor);
+                core = number;
             }
         }
+        finishEntry();
     }
 
     // Start scheduling on the current CPU + 1.