Merge pull request bitcoin#1151 from sickpig/fix-virt-cores

[PORT] Default to virtual cores and set appropriate thread scheduler

src/init.cpp

@@ -395,6 +395,8 @@ void ThreadImport(std::vector<fs::path> vImportFiles)
 {
     const CChainParams &chainparams = Params();
     RenameThread("bitcoin-loadblk");
+    ScheduleBatchPriority();
+
     // -reindex
     if (fReindex)
     {

src/util.cpp

@@ -42,6 +42,7 @@
 
 #include <algorithm>
 #include <fcntl.h>
+#include <sched.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
 
@@ -89,6 +90,7 @@
 #include <openssl/conf.h>
 #include <openssl/crypto.h>
 #include <openssl/rand.h>
+#include <thread>
 
 std::vector<std::string> splitByCommasAndRemoveSpaces(const std::vector<std::string> &args)
 {
@@ -930,15 +932,7 @@ void SetThreadPriority(int nPriority)
 #endif // WIN32
 }
 
-int GetNumCores()
-{
-#if BOOST_VERSION >= 105600
-    return boost::thread::physical_concurrency();
-#else // Must fall back to hardware_concurrency, which unfortunately counts virtual cores
-    return boost::thread::hardware_concurrency();
-#endif
-}
-
+int GetNumCores() { return std::thread::hardware_concurrency(); }
 std::string CopyrightHolders(const std::string &strPrefix)
 {
     std::string strCopyrightHolders = strPrefix + _(COPYRIGHT_HOLDERS);
@@ -1039,3 +1033,18 @@ bool wildmatch(string pattern, string test)
         test = test.substr(1);
     }
 }
+
+int ScheduleBatchPriority(void)
+{
+#ifdef SCHED_BATCH
+    const static sched_param param{0};
+    if (int ret = pthread_setschedparam(pthread_self(), SCHED_BATCH, &param))
+    {
+        LOGA("Failed to pthread_setschedparam: %s\n", strerror(errno));
+        return ret;
+    }
+    return 0;
+#else
+    return 1;
+#endif
+}

src/util.h

@@ -444,9 +444,8 @@ bool SoftSetArg(const std::string &strArg, const std::string &strValue);
 bool SoftSetBoolArg(const std::string &strArg, bool fValue);
 
 /**
- * Return the number of physical cores available on the current system.
- * @note This does not count virtual cores, such as those provided by HyperThreading
- * when boost is newer than 1.56.
+ * Return the number of cores available on the current system.
+ * @note This does count virtual cores, such as those provided by HyperThreading.
  */
 int GetNumCores();
 
@@ -492,4 +491,13 @@ the second argument will be matched to this pattern. Returns true iff the string
 matches pattern. */
 bool wildmatch(std::string pattern, std::string test);
 
+/**
+ * On platforms that support it, tell the kernel the calling thread is
+ * CPU-intensive and non-interactive. See SCHED_BATCH in sched(7) for details.
+ *
+ * @return The return value of sched_setschedule(), or 1 on systems without
+ * sched_setchedule().
+ */
+int ScheduleBatchPriority(void);
+
 #endif // BITCOIN_UTIL_H