ctdb-locking: Conditionally set real-time priority in lock helper

Signed-off-by: Amitay Isaacs <amitay@gmail.com>
Reviewed-by: Michael Adam <obnox@samba.org>

1 files changed, 33 insertions, 18 deletions

diff --git a/ctdb/server/ctdb_lock_helper.c b/ctdb/server/ctdb_lock_helper.c
index cdcbb4ac635..e41d2307919 100644
--- a/ctdb/server/ctdb_lock_helper.c
+++ b/ctdb/server/ctdb_lock_helper.c
@@ -28,6 +28,35 @@
 #include "common/system.h"
 
 static char *progname = NULL;
+static bool realtime = true;
+
+static void set_priority(void)
+{
+	const char *ptr;
+
+	ptr = getenv("CTDB_NOSETSCHED");
+	if (ptr != NULL) {
+		realtime = false;
+	}
+
+	if (! realtime) {
+		return;
+	}
+
+	realtime = set_scheduler();
+	if (! realtime) {
+		fprintf(stderr,
+			"%s: Unable to set real-time scheduler priority\n",
+			progname);
+	}
+}
+
+static void reset_priority(void)
+{
+	if (realtime) {
+		reset_scheduler();
+	}
+}
 
 static void send_result(int fd, char result)
 {
@@ -69,7 +98,6 @@ static int lock_record(const char *dbpath, const char *dbflags, const char *dbke
 	TDB_DATA key;
 	struct tdb_context *tdb;
 	int tdb_flags;
-	bool realtime;
 
 	/* No error checking since CTDB always passes sane values */
 	tdb_flags = strtol(dbflags, NULL, 0);
@@ -88,11 +116,7 @@ static int lock_record(const char *dbpath, const char *dbflags, const char *dbke
 		return 1;
 	}
 
-	realtime = set_scheduler();
-	if (! realtime) {
-		fprintf(stderr, "%s: Unable to set real-time scheduler priority\n",
-			progname);
-	}
+	set_priority();
 
 	if (tdb_chainlock(tdb, key) < 0) {
 		fprintf(stderr, "%s: Error getting record lock (%s)\n",
@@ -100,9 +124,7 @@ static int lock_record(const char *dbpath, const char *dbflags, const char *dbke
 		return 1;
 	}
 
-	if (realtime) {
-		reset_scheduler();
-	}
+	reset_priority();
 
 	return 0;
 
@@ -113,7 +135,6 @@ static int lock_db(const char *dbpath, const char *dbflags)
 {
 	struct tdb_context *tdb;
 	int tdb_flags;
-	bool realtime;
 
 	/* No error checking since CTDB always passes sane values */
 	tdb_flags = strtol(dbflags, NULL, 0);
@@ -124,11 +145,7 @@ static int lock_db(const char *dbpath, const char *dbflags)
 		return 1;
 	}
 
-	realtime = set_scheduler();
-	if (! realtime) {
-		fprintf(stderr, "%s: Unable to set real-time scheduler priority\n",
-			progname);
-	}
+	set_priority();
 
 	if (tdb_lockall(tdb) < 0) {
 		fprintf(stderr, "%s: Error getting db lock (%s)\n",
@@ -136,9 +153,7 @@ static int lock_db(const char *dbpath, const char *dbflags)
 		return 1;
 	}
 
-	if (realtime) {
-		reset_scheduler();
-	}
+	reset_priority();
 
 	return 0;
 }