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From: Aaro Koskinen <aaro.koskinen@iki.fi>
To: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	James Morse <james.morse@arm.com>,
	Jayachandran Chandrasekharan Nair <jnair@marvell.com>
Cc: Aaro Koskinen <aaro.koskinen@nokia.com>,
	linux-arm-kernel@lists.infradead.org,
	Aaro Koskinen <aaro.koskinen@iki.fi>
Subject: [PATCH 2/2] arm64: Implement panic_smp_self_stop()
Date: Tue, 11 Jun 2019 21:10:50 +0300	[thread overview]
Message-ID: <20190611181050.9647-2-aaro.koskinen@iki.fi> (raw)
In-Reply-To: <20190611181050.9647-1-aaro.koskinen@iki.fi>

From: Aaro Koskinen <aaro.koskinen@nokia.com>

Currently arm64 uses the default implementation of panic_smp_self_stop()
that is simply a cpu_relax() loop. As a result, when two CPUs panic()
simultaneously we get "SMP: failed to stop secondary CPUs" warnings and
extra delays before a reset.

Provide an implementation of panic_smp_self_stop() that offlines the
CPU properly.

Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
---
 arch/arm64/kernel/smp.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 1a1b96a50245..5e09e5032409 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -857,6 +857,11 @@ static void ipi_cpu_stop(unsigned int cpu)
 	cpu_park_loop();
 }
 
+void panic_smp_self_stop(void)
+{
+	ipi_cpu_stop(smp_processor_id());
+}
+
 #ifdef CONFIG_KEXEC_CORE
 static atomic_t waiting_for_crash_ipi = ATOMIC_INIT(0);
 #endif
-- 
2.17.0


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  reply	other threads:[~2019-06-11 18:11 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-11 18:10 [PATCH 1/2] arm64: Improve parking of stopped CPUs Aaro Koskinen
2019-06-11 18:10 ` Aaro Koskinen [this message]
2019-06-12 15:18   ` [PATCH 2/2] arm64: Implement panic_smp_self_stop() James Morse
2019-06-12 22:38     ` Aaro Koskinen
2019-06-13  9:21   ` Will Deacon
2019-06-13  9:22 ` [PATCH 1/2] arm64: Improve parking of stopped CPUs Will Deacon

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