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+---
+layout: forum
+title: 'Re: bitcoin auto-renice-ing'
+grand_parent: Forum Posts
+parent: Bitcoin Forum
+nav_order: 86
+date: 2010-03-15 18:44:12 UTC
+original: https://bitcointalk.org/index.php?topic=72.msg717#msg717
+---
+
+# Re: bitcoin auto-renice-ing
+
+---
+
+```
+Re: bitcoin auto-renice-ing
+March 15, 2010, 06:44:12 PM
+
+It sets different priorities for each thread.  The generate threads run at PRIO_MIN.  The other threads rarely take any CPU and run at normal.
+
+#define THREAD_PRIORITY_LOWEST          PRIO_MIN
+#define THREAD_PRIORITY_BELOW_NORMAL    2
+#define THREAD_PRIORITY_NORMAL          0
+
+The priorities converted from Windows priorities were probably from a table like this:
+
+   "The following table shows the mapping between nice values and Win32 priorities. Refer to the Win32 documentation for SetThreadPriority() for more information on Win32 priority issues.
+
+nice value    Win32 Priority
+-20 to -16    THREAD_PRIORITY_HIGHEST
+-15 to -6    THREAD_PRIORITY_ABOVE_NORMAL
+-5 to +4    THREAD_PRIORITY_NORMAL
+5 to +14    THREAD_PRIORITY_BELOW_NORMAL
+15 to +19    THREAD_PRIORITY_LOWEST"
+
+If you have better values, suggestions welcome.
+
+Also, there was some advice on the web that PRIO_PROCESS is used on Linux because threads are processes.  If that's not true, maybe it accounts for unexpectedly setting the priority of the whole app.
+
+    // threads are processes on linux, so PRIO_PROCESS affects just the one thread
+    setpriority(PRIO_PROCESS, getpid(), nPriority);
+    ```