From: Nathan Lynch <nathanl@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Subject: [PATCH 2/3] powerpc/pseries/mobility: prevent cpu hotplug during DT update
Date: Tue, 11 Jun 2019 23:45:05 -0500 [thread overview]
Message-ID: <20190612044506.16392-3-nathanl@linux.ibm.com> (raw)
In-Reply-To: <20190612044506.16392-1-nathanl@linux.ibm.com>
CPU online/offline code paths are sensitive to parts of the device
tree (various cpu node properties, cache nodes) that can be changed as
a result of a migration.
Prevent CPU hotplug while the device tree potentially is inconsistent.
Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
---
arch/powerpc/platforms/pseries/mobility.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index 88925f8ca8a0..edc1ec408589 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -9,6 +9,7 @@
* 2 as published by the Free Software Foundation.
*/
+#include <linux/cpu.h>
#include <linux/kernel.h>
#include <linux/kobject.h>
#include <linux/smp.h>
@@ -338,11 +339,19 @@ void post_mobility_fixup(void)
if (rc)
printk(KERN_ERR "Post-mobility activate-fw failed: %d\n", rc);
+ /*
+ * We don't want CPUs to go online/offline while the device
+ * tree is being updated.
+ */
+ cpus_read_lock();
+
rc = pseries_devicetree_update(MIGRATION_SCOPE);
if (rc)
printk(KERN_ERR "Post-mobility device tree update "
"failed: %d\n", rc);
+ cpus_read_unlock();
+
/* Possibly switch to a new RFI flush type */
pseries_setup_rfi_flush();
--
2.20.1
next prev parent reply other threads:[~2019-06-12 4:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-12 4:45 [PATCH 0/3] live partition migration vs cacheinfo Nathan Lynch
2019-06-12 4:45 ` [PATCH 1/3] powerpc/cacheinfo: add cacheinfo_teardown, cacheinfo_rebuild Nathan Lynch
2019-06-14 5:55 ` Gautham R Shenoy
2019-06-15 13:36 ` Michael Ellerman
2019-06-12 4:45 ` Nathan Lynch [this message]
2019-06-13 16:52 ` [PATCH 2/3] powerpc/pseries/mobility: prevent cpu hotplug during DT update Gautham R Shenoy
2019-06-12 4:45 ` [PATCH 3/3] powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migration Nathan Lynch
2019-06-14 5:56 ` Gautham R Shenoy
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