From: Frederic Weisbecker <frederic@kernel.org>
Date: Mon, 26 May 2025 11:06:21 +0000 (+0200)
Subject: sched/isolation: Save boot defined domain flags
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4fca0e550d506e1c95504c2d9247bc92bf621bf6;p=thirdparty%2Flinux.git

sched/isolation: Save boot defined domain flags

HK_TYPE_DOMAIN will soon integrate not only boot defined isolcpus= CPUs
but also cpuset isolated partitions.

Housekeeping still needs a way to record what was initially passed
to isolcpus= in order to keep these CPUs isolated after a cpuset
isolated partition is modified or destroyed while containing some of
them.

Create a new HK_TYPE_DOMAIN_BOOT to keep track of those.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marco Crivellari <marco.crivellari@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
---

diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h
index d8501f4709b58..c7cf6934489cd 100644
--- a/include/linux/sched/isolation.h
+++ b/include/linux/sched/isolation.h
@@ -7,8 +7,12 @@
 #include <linux/tick.h>
 
 enum hk_type {
+	/* Inverse of boot-time isolcpus= argument */
+	HK_TYPE_DOMAIN_BOOT,
 	HK_TYPE_DOMAIN,
+	/* Inverse of boot-time isolcpus=managed_irq argument */
 	HK_TYPE_MANAGED_IRQ,
+	/* Inverse of boot-time nohz_full= or isolcpus=nohz arguments */
 	HK_TYPE_KERNEL_NOISE,
 	HK_TYPE_MAX,
 
diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index 3ad0d6df6a0a2..11a623fa63205 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -11,6 +11,7 @@
 #include "sched.h"
 
 enum hk_flags {
+	HK_FLAG_DOMAIN_BOOT	= BIT(HK_TYPE_DOMAIN_BOOT),
 	HK_FLAG_DOMAIN		= BIT(HK_TYPE_DOMAIN),
 	HK_FLAG_MANAGED_IRQ	= BIT(HK_TYPE_MANAGED_IRQ),
 	HK_FLAG_KERNEL_NOISE	= BIT(HK_TYPE_KERNEL_NOISE),
@@ -239,7 +240,7 @@ static int __init housekeeping_isolcpus_setup(char *str)
 
 		if (!strncmp(str, "domain,", 7)) {
 			str += 7;
-			flags |= HK_FLAG_DOMAIN;
+			flags |= HK_FLAG_DOMAIN | HK_FLAG_DOMAIN_BOOT;
 			continue;
 		}
 
@@ -269,7 +270,7 @@ static int __init housekeeping_isolcpus_setup(char *str)
 
 	/* Default behaviour for isolcpus without flags */
 	if (!flags)
-		flags |= HK_FLAG_DOMAIN;
+		flags |= HK_FLAG_DOMAIN | HK_FLAG_DOMAIN_BOOT;
 
 	return housekeeping_setup(str, flags);
 }