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From:   Nitesh Narayan Lal <nitesh@redhat.com>
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Subject: [PATCH v2 2/4] sched/isolation: Extend nohz_full to isolate managed IRQs
Date:   Wed, 23 Sep 2020 14:11:24 -0400
Message-Id: <20200923181126.223766-3-nitesh@redhat.com>
In-Reply-To: <20200923181126.223766-1-nitesh@redhat.com>
References: <20200923181126.223766-1-nitesh@redhat.com>
Precedence: bulk

Extend nohz_full feature set to include isolation from managed IRQS. This
is required specifically for setups that only uses nohz_full and still
requires isolation for maintaining lower latency for the listed CPUs.

Having this change will ensure that the kernel functions that were using
HK_FLAG_MANAGED_IRQ to derive cpumask for pinning various jobs/IRQs do not
enqueue anything on the CPUs listed under nohz_full.

Suggested-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
---
 kernel/sched/isolation.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index 5a6ea03f9882..9df9598a9e39 100644
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -141,7 +141,7 @@ static int __init housekeeping_nohz_full_setup(char *str)
 	unsigned int flags;
 
 	flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU |
-		HK_FLAG_MISC | HK_FLAG_KTHREAD;
+		HK_FLAG_MISC | HK_FLAG_KTHREAD | HK_FLAG_MANAGED_IRQ;
 
 	return housekeeping_setup(str, flags);
 }
-- 
2.18.2