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| author | Michael Bringmann <mwb@linux.vnet.ibm.com> | 2017-11-29 01:58:43 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-01-27 12:59:45 +0300 |
| commit | e67e02a544e9a0d24b99eb383e808bb3433b048d (patch) | |
| tree | 25273be02407c4cc3748b61c1d9f837eab407e55 | |
| parent | ea05ba7c559c8e5a5946c3a94a2a266e9a6680a6 (diff) | |
| download | linux-e67e02a544e9a0d24b99eb383e808bb3433b048d.tar.xz | |
powerpc/pseries: Fix cpu hotplug crash with memoryless nodes
On powerpc systems with shared configurations of CPUs and memory and
memoryless nodes at boot, an event ordering problem was observed on a
SLES12 build platforms with the hot-add of CPUs to the memoryless
nodes.
* The most common error occurred when the memory SLAB driver attempted
to reference the memoryless node to which a CPU was being added
before the kernel had finished initializing all of the data
structures for the CPU and exited 'device_online' under
DLPAR/hot-add.
Normally the memoryless node would be initialized through the call
path device_online ... arch_update_cpu_topology ... find_cpu_nid ...
try_online_node. This patch ensures that the powerpc node will be
initialized as early as possible, even if it was memoryless and
CPU-less at the point when we are trying to hot-add a new CPU to it.
Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| -rw-r--r-- | arch/powerpc/mm/numa.c | 4 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/hotplug-cpu.c | 3 |
2 files changed, 6 insertions, 1 deletions
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 1bead2c67272..314d19ab9385 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1198,7 +1198,7 @@ static long vphn_get_associativity(unsigned long cpu, return rc; } -static inline int find_and_online_cpu_nid(int cpu) +int find_and_online_cpu_nid(int cpu) { __be32 associativity[VPHN_ASSOC_BUFSIZE] = {0}; int new_nid; @@ -1229,6 +1229,8 @@ static inline int find_and_online_cpu_nid(int cpu) #endif } + pr_debug("%s:%d cpu %d nid %d\n", __FUNCTION__, __LINE__, + cpu, new_nid); return new_nid; } diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c index a7d14aa7bb7c..dceb51454d8d 100644 --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -340,6 +340,8 @@ static void pseries_remove_processor(struct device_node *np) cpu_maps_update_done(); } +extern int find_and_online_cpu_nid(int cpu); + static int dlpar_online_cpu(struct device_node *dn) { int rc = 0; @@ -364,6 +366,7 @@ static int dlpar_online_cpu(struct device_node *dn) != CPU_STATE_OFFLINE); cpu_maps_update_done(); timed_topology_update(1); + find_and_online_cpu_nid(cpu); rc = device_online(get_cpu_device(cpu)); if (rc) goto out; |