From: Andrew Tridgell <tridge@samba.org>
Date: Thu, 12 Jul 2007 23:35:46 +0000 (+1000)
Subject: fully save/restore scheduler parameters
X-Git-Tag: tevent-0.9.20~348^2~2453
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=d2a5af7eb800612f02c72018e169bc676e23b3ba;p=thirdparty%2Fsamba.git

fully save/restore scheduler parameters
(This used to be ctdb commit 59408eabe7515d49a6eef3b6fb2590a1cd1df956)
---

diff --git a/ctdb/common/ctdb_util.c b/ctdb/common/ctdb_util.c
index f8f7cb5150a..4890a141ea7 100644
--- a/ctdb/common/ctdb_util.c
+++ b/ctdb/common/ctdb_util.c
@@ -192,20 +192,42 @@ struct ctdb_rec_data *ctdb_marshall_record(TALLOC_CTX *mem_ctx, uint32_t reqid,
 /*
   if possible, make this task real time
  */
-void ctdb_set_realtime(bool enable)
+void ctdb_set_scheduler(struct ctdb_context *ctdb)
 {
-#if HAVE_SCHED_SETSCHEDULER
+#if HAVE_SCHED_SETSCHEDULER	
 	struct sched_param p;
-	p.__sched_priority = 1;
-
-	if (enable) {
-		if (sched_setscheduler(getpid(), SCHED_FIFO, &p) == -1) {
-			DEBUG(0,("Unable to set scheduler to SCHED_FIFO (%s)\n", strerror(errno)));
-		} else {
-			DEBUG(0,("Set scheduler to SCHED_FIFO\n"));
-		}
+
+	if (ctdb->saved_scheduler_param == NULL) {
+		ctdb->saved_scheduler_param = talloc_size(ctdb, sizeof(p));
+	}
+	
+	if (sched_getparam(0, (struct sched_param *)ctdb->saved_scheduler_param) == -1) {
+		DEBUG(0,("Unable to get old scheduler params\n"));
+		return;
+	}
+
+	p = *(struct sched_param *)ctdb->saved_scheduler_param;
+	p.sched_priority = 1;
+
+	if (sched_setscheduler(0, SCHED_FIFO, &p) == -1) {
+		DEBUG(0,("Unable to set scheduler to SCHED_FIFO (%s)\n", strerror(errno)));
 	} else {
-		sched_setscheduler(getpid(), SCHED_OTHER, &p);
+		DEBUG(0,("Set scheduler to SCHED_FIFO\n"));
+	}
+#endif
+}
+
+/*
+  restore previous scheduler parameters
+ */
+void ctdb_restore_scheduler(struct ctdb_context *ctdb)
+{
+#if HAVE_SCHED_SETSCHEDULER	
+	if (ctdb->saved_scheduler_param == NULL) {
+		ctdb_fatal(ctdb, "No saved scheduler parameters\n");
+	}
+	if (sched_setscheduler(0, SCHED_OTHER, (struct sched_param *)ctdb->saved_scheduler_param) == -1) {
+		ctdb_fatal(ctdb, "Unable to restore old scheduler parameters\n");
 	}
 #endif
 }
diff --git a/ctdb/include/ctdb_private.h b/ctdb/include/ctdb_private.h
index b584794f1c9..be3b832832a 100644
--- a/ctdb/include/ctdb_private.h
+++ b/ctdb/include/ctdb_private.h
@@ -308,6 +308,7 @@ struct ctdb_context {
 	struct ctdb_tcp_list *tcp_list;
 	struct ctdb_client_ip *client_ip_list;
 	bool do_setsched;
+	void *saved_scheduler_param;
 };
 
 struct ctdb_db_context {
@@ -948,7 +949,8 @@ int ctdb_ctrl_set_rsn_nonempty(struct ctdb_context *ctdb, struct timeval timeout
 			       uint32_t destnode, uint32_t db_id, uint64_t rsn);
 int ctdb_ctrl_delete_low_rsn(struct ctdb_context *ctdb, struct timeval timeout, 
 			     uint32_t destnode, uint32_t db_id, uint64_t rsn);
-void ctdb_set_realtime(bool enable);
+void ctdb_set_scheduler(struct ctdb_context *ctdb);
+void ctdb_restore_scheduler(struct ctdb_context *ctdb);
 int32_t ctdb_control_takeover_ip(struct ctdb_context *ctdb, 
 				 struct ctdb_req_control *c,
 				 TDB_DATA indata, 
diff --git a/ctdb/server/ctdb_daemon.c b/ctdb/server/ctdb_daemon.c
index ce84db3e685..546c7fca019 100644
--- a/ctdb/server/ctdb_daemon.c
+++ b/ctdb/server/ctdb_daemon.c
@@ -646,7 +646,7 @@ int ctdb_start_daemon(struct ctdb_context *ctdb, bool do_fork)
 
 	if (ctdb->do_setsched) {
 		/* try to set us up as realtime */
-		ctdb_set_realtime(true);
+		ctdb_set_scheduler(ctdb);
 	}
 
 	/* ensure the socket is deleted on exit of the daemon */
diff --git a/ctdb/server/eventscript.c b/ctdb/server/eventscript.c
index fab9175ed29..f40cda18bdb 100644
--- a/ctdb/server/eventscript.c
+++ b/ctdb/server/eventscript.c
@@ -167,7 +167,7 @@ int ctdb_event_script_callback(struct ctdb_context *ctdb,
 	if (state->child == 0) {
 		close(state->fd[0]);
 		if (ctdb->do_setsched) {
-			ctdb_set_realtime(false);
+			ctdb_restore_scheduler(ctdb);
 		}
 		set_close_on_exec(state->fd[1]);
 		va_start(ap, fmt);