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] feature: 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 | 8 +++++++-
 irqbalance.h | 1 +
 irqlist.c    | 3 ++-
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/irqbalance.c b/irqbalance.c
index 9449e40..82ac3ea 100644
--- a/irqbalance.c
+++ b/irqbalance.c
@@ -72,6 +72,7 @@ GMainLoop *main_loop;
 char *cpu_ban_string = NULL;
 char *banned_cpumask_from_ui = NULL;
 unsigned long migrate_ratio = 0;
+unsigned long load_limit = 0;
 
 static void sleep_approx(int seconds)
 {
@@ -106,6 +107,7 @@ struct option lopts[] = {
 	{"hintpolicy", 1, NULL, 'h'},
 	{"verifyhint", 1, NULL, 'v'},
 	{"notclearhint", 0, NULL, 'n'},
+	{"loadlimit", 1, NULL, 'g'},
 	{0, 0, 0, 0}
 };
 
@@ -115,6 +117,7 @@ static void usage(void)
 	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>] [--migrateval= | -e <n>]\n");
 	log(TO_CONSOLE, LOG_INFO, "	[--rulesconfig= | -r <config>] [--hintpolicy | -h <subset>] [--verifyhint= | -v n] [--notclearhint | -n]\n");
+	log(TO_CONSOLE, LOG_INFO, "	[--loadlimit= | -g <n>]\n");
 }
 
 static void version(void)
@@ -129,7 +132,7 @@ static void parse_command_line(int argc, char **argv)
 	unsigned long val;
 
 	while ((opt = getopt_long(argc, argv,
-		"odfjVni:p:s:c:l:m:t:e:r:h:v:",
+		"odfjVni:p:s:c:l:m:t:e:r:h:v:g:",
 		lopts, &longind)) != -1) {
 
 		switch(opt) {
@@ -223,6 +226,9 @@ static void parse_command_line(int argc, char **argv)
 			case 'n':
 				clear_affinity_hint = 0;
 				break;
+			case 'g':
+				load_limit = strtoul(optarg, NULL, 10);
+				break;
 		}
 	}
 }
diff --git a/irqbalance.h b/irqbalance.h
index 4a73b83..9ff8f37 100644
--- a/irqbalance.h
+++ b/irqbalance.h
@@ -83,6 +83,7 @@ extern cpumask_t banned_cpus;
 extern cpumask_t unbanned_cpus;
 extern long HZ;
 extern unsigned long migrate_ratio;
+extern unsigned long load_limit;
 
 /*
  * Numa node access routines
diff --git a/irqlist.c b/irqlist.c
index 9ab321a..98a4224 100644
--- a/irqlist.c
+++ b/irqlist.c
@@ -97,7 +97,8 @@ static void move_candidate_irqs(struct irq_info *info, void *data)
 	}
 
 	/* If we can migrate an irq without swapping the imbalance do it. */
-	if ((lb_info->min_load + info->load) - (lb_info->adjustment_load - info->load) < delta_load) {
+	if ((lb_info->min_load + info->load) - (lb_info->adjustment_load - info->load) < delta_load &&
+		lb_info->adjustment_load > load_limit) {
 		lb_info->adjustment_load -= info->load;
 		lb_info->min_load += info->load;
 		if (lb_info->min_load > lb_info->adjustment_load) {
-- 
2.23.0