From 2db1d513904b6dda3644a84a221bae074ee93b66 Mon Sep 17 00:00:00 2001
From: "Jean M. Cyr" <jean.m.cyr@gmail.com>
Date: Mon, 21 Jan 2019 19:01:19 -0500
Subject: [PATCH] Lower the compiler background thread priority.

---
 libethash-cl/CLMiner.cpp     | 14 ++++++++++++++
 libethash-cuda/CUDAMiner.cpp | 15 ++++++++++++++-
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/libethash-cl/CLMiner.cpp b/libethash-cl/CLMiner.cpp
index 00b299c3a..976e19294 100644
--- a/libethash-cl/CLMiner.cpp
+++ b/libethash-cl/CLMiner.cpp
@@ -870,7 +870,21 @@ void CLMiner::asyncCompile()
 {
     auto saveName = getThreadName();
     setThreadName(name().c_str());
+
+#if defined(__linux__)
+    // Non Posix hack to lower compile thread's priority. Under POSIX
+    // the nice value is a process attribute, under Linux it's a thread
+    // attribute
+    if (nice(5) == -1)
+        cllog << "Unable to lower compiler priority.";
+#endif
+#ifdef WIN32
+    if (!SetThreadPriority(m_compileThread->native_handle(), THREAD_PRIORITY_BELOW_NORMAL))
+        cllog << "Unable to lower compiler priority.";
+#endif
+
     compileKernel(m_nextProgpowPeriod, m_nextProgram, m_nextSearchKernel);
+
     setThreadName(saveName.c_str());
 }
 
diff --git a/libethash-cuda/CUDAMiner.cpp b/libethash-cuda/CUDAMiner.cpp
index ea2e5334d..6b3907565 100644
--- a/libethash-cuda/CUDAMiner.cpp
+++ b/libethash-cuda/CUDAMiner.cpp
@@ -332,10 +332,23 @@ void CUDAMiner::enumDevices(std::map<string, DeviceDescriptor>& _DevicesCollecti
 
 void CUDAMiner::asyncCompile()
 {
-    cuCtxSetCurrent(m_context);
     auto saveName = getThreadName();
     setThreadName(name().c_str());
 
+#if defined(__linux__)
+    // Non Posix hack to lower compile thread's priority. Under POSIX
+    // the nice value is a process attribute, under Linux it's a thread
+    // attribute
+    if (nice(5) == -1)
+        cudalog << "Unable to lower compiler priority.";
+#endif
+#ifdef WIN32
+    if (!SetThreadPriority(m_compileThread->native_handle(), THREAD_PRIORITY_BELOW_NORMAL))
+        cudalog << "Unable to lower compiler priority.";
+#endif
+
+    cuCtxSetCurrent(m_context);
+
     compileKernel(m_nextProgpowPeriod, m_epochContext.dagNumItems / 2, m_kernel[m_kernelCompIx]);
 
     setThreadName(saveName.c_str());