Set SCHED_BATCH priority on the loadblk thread.

While reading another PR I saw a mention of #6358. The use case for
SCHED_BATCH is to hint to the kernel that the thread is running a
non-interactive workload that consumes a lot of CPU time. This is
helpful on desktop machines where the loadblk thread can interfere with
interactive applications. More details can be found in the sched(7) man
page.

1 files changed, 15 insertions, 0 deletions

diff --git a/src/util.cpp b/src/util.cpp
index 494d5c4eaf..842d4f6e19 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -31,6 +31,7 @@
 
 #include <algorithm>
 #include <fcntl.h>
+#include <sched.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
 
@@ -966,3 +967,17 @@ fs::path AbsPathForConfigVal(const fs::path& path, bool net_specific)
 {
     return fs::absolute(path, GetDataDir(net_specific));
 }
+
+int ScheduleBatchPriority(void)
+{
+#ifdef SCHED_BATCH
+    const static sched_param param{.sched_priority = 0};
+    if (int ret = pthread_setschedparam(0, SCHED_BATCH, &param)) {
+        LogPrintf("Failed to pthread_setschedparam: %s\n", strerror(errno));
+        return ret;
+    }
+    return 0;
+#else
+    return 1;
+#endif
+}