[PATCH V3 1/2] powerpc/numa: Update CPU topology when VPHN enabled

[PATCH V3 1/2] powerpc/numa: Update CPU topology when VPHN enabled

[Michael Bringmann]

powerpc/numa: Correct the currently broken capability to set the
topology for shared CPUs in LPARs.  At boot time for shared CPU
lpars, the topology for each shared CPU is set to node zero, however,
this is now updated correctly using the Virtual Processor Home Node
(VPHN) capabilities information provided by the pHyp. The VPHN handling
in Linux is disabled, if PRRN handling is present.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in V3:
 -- Remove change unrelated to this patch
---
 arch/powerpc/mm/numa.c                 |   19 ++++++++++++++++++-
 arch/powerpc/platforms/pseries/dlpar.c |    2 ++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 371792e..15c2dd5 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -29,6 +29,7 @@
 #include <linux/seq_file.h>
 #include <linux/uaccess.h>
 #include <linux/slab.h>
+#include <linux/sched.h>
 #include <asm/cputhreads.h>
 #include <asm/sparsemem.h>
 #include <asm/prom.h>
@@ -42,6 +43,8 @@
 #include <asm/vdso.h>
 
 static int numa_enabled = 1;
+static int topology_inited;
+static int topology_update_needed;
 
 static char *cmdline __initdata;
 
@@ -1321,8 +1324,11 @@ int arch_update_cpu_topology(void)
 	struct device *dev;
 	int weight, new_nid, i = 0;
 
-	if (!prrn_enabled && !vphn_enabled)
+	if (!prrn_enabled && !vphn_enabled) {
+		if (!topology_inited)
+			topology_update_needed = 1;
 		return 0;
+	}
 
 	weight = cpumask_weight(&cpu_associativity_changes_mask);
 	if (!weight)
@@ -1361,6 +1367,8 @@ int arch_update_cpu_topology(void)
 			cpumask_andnot(&cpu_associativity_changes_mask,
 					&cpu_associativity_changes_mask,
 					cpu_sibling_mask(cpu));
+			pr_info("Assoc chg gives same node %d for cpu%d\n",
+					new_nid, cpu);
 			cpu = cpu_last_thread_sibling(cpu);
 			continue;
 		}
@@ -1377,6 +1385,9 @@ int arch_update_cpu_topology(void)
 		cpu = cpu_last_thread_sibling(cpu);
 	}
 
+	if (i)
+		updates[i-1].next = NULL;
+
 	pr_debug("Topology update for the following CPUs:\n");
 	if (cpumask_weight(&updated_cpus)) {
 		for (ud = &updates[0]; ud; ud = ud->next) {
@@ -1423,6 +1434,7 @@ int arch_update_cpu_topology(void)
 
 out:
 	kfree(updates);
+	topology_update_needed = 0;
 	return changed;
 }
 
@@ -1600,6 +1612,11 @@ static int topology_update_init(void)
 	if (!proc_create("powerpc/topology_updates", 0644, NULL, &topology_ops))
 		return -ENOMEM;
 
+	topology_inited = 1;
+	if (topology_update_needed)
+		bitmap_fill(cpumask_bits(&cpu_associativity_changes_mask),
+					nr_cpumask_bits);
+
 	return 0;
 }
 device_initcall(topology_update_init);
diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c
index bda18d8..5106263 100644
--- a/arch/powerpc/platforms/pseries/dlpar.c
+++ b/arch/powerpc/platforms/pseries/dlpar.c
@@ -592,6 +592,8 @@ static ssize_t dlpar_show(struct class *class, struct class_attribute *attr,
 
 static int __init pseries_dlpar_init(void)
 {
+	arch_update_cpu_topology();
+
 	pseries_hp_wq = alloc_workqueue("pseries hotplug workqueue",
 					WQ_UNBOUND, 1);
 	return sysfs_create_file(kernel_kobj, &class_attr_dlpar.attr);

Re: [PATCH V3 1/2] powerpc/numa: Update CPU topology when VPHN enabled

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 1733 bytes --]

Hi Michael,

[auto build test ERROR on powerpc/next]
[also build test ERROR on v4.12-rc3 next-20170602]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Michael-Bringmann/powerpc-numa-Update-CPU-topology-when-VPHN-enabled/20170527-052650
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-cell_defconfig (attached as .config)
compiler: powerpc64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
        wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=powerpc 

All errors (new ones prefixed by >>):

>> arch/powerpc/mm/numa.c:47:12: error: 'topology_update_needed' defined but not used [-Werror=unused-variable]
    static int topology_update_needed;
               ^~~~~~~~~~~~~~~~~~~~~~
>> arch/powerpc/mm/numa.c:46:12: error: 'topology_inited' defined but not used [-Werror=unused-variable]
    static int topology_inited;
               ^~~~~~~~~~~~~~~
   cc1: all warnings being treated as errors

vim +/topology_update_needed +47 arch/powerpc/mm/numa.c

    40	#include <asm/paca.h>
    41	#include <asm/hvcall.h>
    42	#include <asm/setup.h>
    43	#include <asm/vdso.h>
    44	
    45	static int numa_enabled = 1;
  > 46	static int topology_inited;
  > 47	static int topology_update_needed;
    48	
    49	static char *cmdline __initdata;
    50	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 19166 bytes --]

Re: [PATCH V3 1/2] powerpc/numa: Update CPU topology when VPHN enabled

[Michael Bringmann]

This build appears to be using V3 of the patch.  V4 of the patch corrected the placement
of the local variables with respect to '#ifdef CONFIG_PPC_SPLPAR'.

On 06/03/2017 10:13 PM, kbuild test robot wrote:
> Hi Michael,
> 
> [auto build test ERROR on powerpc/next]
> [also build test ERROR on v4.12-rc3 next-20170602]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
> 
> url:    https://github.com/0day-ci/linux/commits/Michael-Bringmann/powerpc-numa-Update-CPU-topology-when-VPHN-enabled/20170527-052650
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
> config: powerpc-cell_defconfig (attached as .config)
> compiler: powerpc64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
> reproduce:
>         wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # save the attached .config to linux build tree
>         make.cross ARCH=powerpc 
> 
> All errors (new ones prefixed by >>):
> 
>>> arch/powerpc/mm/numa.c:47:12: error: 'topology_update_needed' defined but not used [-Werror=unused-variable]
>     static int topology_update_needed;
>                ^~~~~~~~~~~~~~~~~~~~~~
>>> arch/powerpc/mm/numa.c:46:12: error: 'topology_inited' defined but not used [-Werror=unused-variable]
>     static int topology_inited;
>                ^~~~~~~~~~~~~~~
>    cc1: all warnings being treated as errors
> 
> vim +/topology_update_needed +47 arch/powerpc/mm/numa.c
> 
>     40	#include <asm/paca.h>
>     41	#include <asm/hvcall.h>
>     42	#include <asm/setup.h>
>     43	#include <asm/vdso.h>
>     44	
>     45	static int numa_enabled = 1;
>   > 46	static int topology_inited;
>   > 47	static int topology_update_needed;
>     48	
>     49	static char *cmdline __initdata;
>     50	
> 
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
> 

-- 
Michael W. Bringmann
Linux Technology Center
IBM Corporation
Tie-Line  363-5196
External: (512) 286-5196
Cell:       (512) 466-0650
mwb@linux.vnet.ibm.com

Re: [PATCH V3 1/2] powerpc/numa: Update CPU topology when VPHN enabled

[Michael Ellerman]

Michael Bringmann <mwb@linux.vnet.ibm.com> writes:

> This build appears to be using V3 of the patch.  V4 of the patch corrected the placement
> of the local variables with respect to '#ifdef CONFIG_PPC_SPLPAR'.

Yes it is, you can tell because it's a reply to "PATCH V3".

cheers

[PATCH V3 2/2] powerpc/hotplug/mm: Fix hot-add memory node assoc

[Michael Bringmann]

Removing or adding memory via the PowerPC hotplug interface currently
dumps newly added processors or memory into default node 0, instead of
into the node that would be calculated based upon the VPHN affinity
tables.  The code was updated to ensure that all nodes found at boot
are still available to subsequent DLPAR hotplug-memory operations,
even if they are not needed at boot time.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in V3:
  -- Remove code not relevant to this defect.
---
 arch/powerpc/mm/numa.c |    7 -------
 1 file changed, 7 deletions(-)

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 15c2dd5..18f3038 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -907,13 +907,6 @@ void __init initmem_init(void)
 
 	memblock_dump_all();
 
-	/*
-	 * Reduce the possible NUMA nodes to the online NUMA nodes,
-	 * since we do not support node hotplug. This ensures that  we
-	 * lower the maximum NUMA node ID to what is actually present.
-	 */
-	nodes_and(node_possible_map, node_possible_map, node_online_map);
-
 	for_each_online_node(nid) {
 		unsigned long start_pfn, end_pfn;