From 84a2df1c9962a87f55e1c0d3bd2118fd754a4b48 Mon Sep 17 00:00:00 2001
From: hejingxian <hejingxian@huawei.com>
Date: Fri, 3 Jan 2020 16:43:28 +0800
Subject: [PATCH] add new irq migrate rule to avoid high cpu irq load

By the old irq migrate rule, the irqs cannot be moved if the adjustment_load will become smaller then
the min_load after moving irq. However, we can accept that the delta load become smaller after moving irq.
---
 irqbalance.c | 14 ++++++++++++--
 irqbalance.h |  3 ++-
 irqlist.c    | 15 ++++++++++++++-
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/irqbalance.c b/irqbalance.c
index 1ca401e..15fb0fe 100644
--- a/irqbalance.c
+++ b/irqbalance.c
@@ -69,6 +69,8 @@ int sleep_interval = SLEEP_INTERVAL;
 long HZ;
 int sleep_interval = SLEEP_INTERVAL;
 int last_interval;
+unsigned long migrate_val = 0;
+unsigned long load_limit = 0;
 GMainLoop *main_loop;
 
 char *cpu_ban_string = NULL;
@@ -106,6 +108,8 @@ struct option lopts[] = {
 	{"banmod", 1 , NULL, 'm'},
 	{"interval", 1 , NULL, 't'},
 	{"version", 0, NULL, 'V'},
+	{"migrateval", 1, NULL, 'e'},
+	{"loadlimit", 1, NULL, 'g'},
 	{0, 0, 0, 0}
 };
 
@@ -114,7 +118,7 @@ static void usage(void)
 {
 	log(TO_CONSOLE, LOG_INFO, "irqbalance [--oneshot | -o] [--debug | -d] [--foreground | -f] [--journal | -j] [--hintpolicy= | -h [exact|subset|ignore]]\n");
 	log(TO_CONSOLE, LOG_INFO, "	[--powerthresh= | -p <off> | <n>] [--banirq= | -i <n>] [--banmod= | -m <module>] [--policyscript= | -l <script>]\n");
-	log(TO_CONSOLE, LOG_INFO, "	[--pid= | -s <file>] [--deepestcache= | -c <n>] [--interval= | -t <n>]\n");
+	log(TO_CONSOLE, LOG_INFO, "	[--pid= | -s <file>] [--deepestcache= | -c <n>] [--interval= | -t <n>] [--migrateval= | -e <n>] [--loadlimit= | -g <n>]\n");
 }
 
 static void version(void)
@@ -129,7 +133,7 @@ static void parse_command_line(int argc, char **argv)
 	unsigned long val;
 
 	while ((opt = getopt_long(argc, argv,
-		"odfjVi:p:s:c:b:l:m:t:",
+		"odfjVi:p:s:c:b:l:m:t:e:g:",
 		lopts, &longind)) != -1) {
 
 		switch(opt) {
@@ -231,6 +235,12 @@ static void parse_command_line(int argc, char **argv)
 					exit(1);
 				}
 				break;
+			case 'e':
+				migrate_val = strtoul(optarg, NULL, 10);
+				break;
+			case 'g':
+				load_limit = strtoul(optarg, NULL, 10);
+				break;
 		}
 	}
 }
diff --git a/irqbalance.h b/irqbalance.h
index 72e141b..d4f6e7a 100644
--- a/irqbalance.h
+++ b/irqbalance.h
@@ -124,7 +124,8 @@ extern struct irq_info *add_new_irq(int irq, struct irq_info *hint, GList *proc_
 extern void add_cl_banned_module(char *modname);
 #define irq_numa_node(irq) ((irq)->numa_node)
 
-
+extern unsigned long migrate_val;
+extern unsigned long load_limit;
 /*
  * Generic object functions
  */
diff --git a/irqlist.c b/irqlist.c
index 95ccc7a..3c38b18 100644
--- a/irqlist.c
+++ b/irqlist.c
@@ -76,6 +76,7 @@ static void compute_deviations(struct topo_obj *obj, void *data)
 static void move_candidate_irqs(struct irq_info *info, void *data)
 {
 	struct load_balance_info *lb_info = data;
+	unsigned long delta_load = 0;
 
 	/* Don't rebalance irqs that don't want it */
 	if (info->level == BALANCE_NONE)
@@ -91,12 +92,24 @@ static void move_candidate_irqs(struct irq_info *info, void *data)
 	if (info->load <= 1)
 		return;
 
+	if (migrate_val > 0) {
+		delta_load = (lb_info->adjustment_load - lb_info->min_load) / migrate_val;
+	}
+
 	/* If we can migrate an irq without swapping the imbalance do it. */
 	if ((lb_info->adjustment_load - info->load) > (lb_info->min_load + info->load)) {
 		lb_info->adjustment_load -= info->load;
 		lb_info->min_load += info->load;
-	} else
+	} else if (delta_load && load_limit && (lb_info->adjustment_load > load_limit) &&
+		(lb_info->min_load + info->load) - (lb_info->adjustment_load - info->load) < delta_load) {
+		lb_info->adjustment_load -= info->load;
+		lb_info->min_load += info->load;
+		if (lb_info->min_load > lb_info->adjustment_load) {
+			lb_info->min_load = lb_info->adjustment_load;
+		}
+	} else {
 		return;
+	}
 
 	log(TO_CONSOLE, LOG_INFO, "Selecting irq %d for rebalancing\n", info->irq);
 
-- 
1.8.3.1