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From:   Laurent Dufour <ldufour@linux.ibm.com>
To:     mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org,
        nathanl@linux.ibm.com, haren@linux.vnet.ibm.com, npiggin@gmail.com
Cc:     linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] powerpc/mobility: disabling hard lockup watchdog during LPM
Date:   Wed,  1 Jun 2022 17:53:15 +0200
Message-Id: <20220601155315.35109-3-ldufour@linux.ibm.com>
In-Reply-To: <20220601155315.35109-1-ldufour@linux.ibm.com>
References: <20220601155315.35109-1-ldufour@linux.ibm.com>
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Disabling the Hard Lockup Watchdog until the memory transfer is complete.

This avoids hard lockup seen while the memory is still in progress when the
system is heavily loaded and a lot of pages are still not transferred on
the arrival side.

Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
---
 arch/powerpc/platforms/pseries/mobility.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index 55612a1b07d6..061d4faefefb 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -701,6 +701,9 @@ static int pseries_migrate_partition(u64 handle)
 
 	vas_migration_handler(VAS_SUSPEND);
 
+	pr_debug("Disabling the NMI watchdog\n");
+	watchdog_nmi_stop();
+
 	ret = pseries_suspend(handle);
 	if (ret == 0) {
 		post_mobility_fixup();
@@ -708,6 +711,9 @@ static int pseries_migrate_partition(u64 handle)
 	} else
 		pseries_cancel_migration(handle, ret);
 
+	pr_debug("Enabling the NMI watchdog again\n");
+	watchdog_nmi_start();
+
 	vas_migration_handler(VAS_RESUME);
 
 	return ret;
-- 
2.36.1