| Message ID | 55ff4b6a-7f43-e171-d214-cf10d466aa71@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | e67e02a544e9a0d24b99eb383e808bb3433b048d |
| Headers | show |
| Series | powerpc/nodes: Fix issues with memoryless nodes | expand |
On 11/28/2017 04:58 PM, Michael Bringmann wrote: > 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> > --- > Changes in V8: > -- Change a 'printk(KERN_INFO ...)' statement to be a pr_debug() > statement. > -- Rename 'find_cpu_nid' to 'find_and_online_cpu_nid' for better > clarity of its function. > --- > arch/powerpc/mm/numa.c | 4 +++- > arch/powerpc/platforms/pseries/hotplug-cpu.c | 3 +++ > 2 files changed, 6 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c > index 6b08dd8..a182f9e 100644 > --- a/arch/powerpc/mm/numa.c > +++ b/arch/powerpc/mm/numa.c > @@ -1307,7 +1307,7 @@ 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; > @@ -1340,6 +1340,8 @@ 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 a7d14aa7..dceb514 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; >
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c index 6b08dd8..a182f9e 100644 --- a/arch/powerpc/mm/numa.c +++ b/arch/powerpc/mm/numa.c @@ -1307,7 +1307,7 @@ 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; @@ -1340,6 +1340,8 @@ 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 a7d14aa7..dceb514 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;
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> --- Changes in V8: -- Change a 'printk(KERN_INFO ...)' statement to be a pr_debug() statement. -- Rename 'find_cpu_nid' to 'find_and_online_cpu_nid' for better clarity of its function. --- arch/powerpc/mm/numa.c | 4 +++- arch/powerpc/platforms/pseries/hotplug-cpu.c | 3 +++ 2 files changed, 6 insertions(+), 1 deletion(-)