memattrs: add MemoryTiersNr=2 info attr to topology

Closes #661

Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>
(cherry picked from commit 0839821
                and commit 6d4df37)

NEWS

@@ -21,6 +21,9 @@ Version 2.11.0
 --------------
 * API
   + Add hwloc_obj_set_subtype().
+* Misc
+  + The MemoryTiersNr info attribute in the root object now says how many
+    memory tiers were built. Thanks to Antoine Morvan for the report.
 * Tools/
   + Option --best-memattr may now return multiple nodes. Additional
     configuration flags may be given to tweak its behavior.

doc/hwloc.doxy

@@ -1,6 +1,6 @@
 /*
  * Copyright © 2009 CNRS
- * Copyright © 2009-2023 Inria.  All rights reserved.
+ * Copyright © 2009-2024 Inria.  All rights reserved.
  * Copyright © 2009-2013 Université Bordeaux
  * Copyright © 2009-2020 Cisco Systems, Inc.  All rights reserved.
  * Copyright © 2020 Hewlett Packard Enterprise.  All rights reserved.
@@ -2032,6 +2032,10 @@ If several components were combined, multiple Backend pairs may exist,
 with different values, for instance <tt>x86</tt> and <tt>Linux</tt> in the root
 object and <tt>CUDA</tt> in CUDA OS device objects.
 </dd>
+<dt>MemoryTiersNr</dt>
+<dd>The number of different memory tiers in the topology, if any.
+See \ref heteromem.
+</dd>
 <dt>SyntheticDescription</dt>
 <dd>The description string that was given to hwloc to build this
 synthetic topology.
@@ -2565,6 +2569,13 @@ $ hwloc-calc -I 'numa[tier=0]' -p all
 2,3
 \endverbatim
 
+The number of tiers may be retrieved by looking at topology attributes
+in the root object:
+\verbatim
+$ hwloc-info --get-attr "info MemoryTiersNr" topology
+2
+\endverbatim
+
 hwloc-calc and hwloc-bind also have options such as
 <tt>\--local-memory</tt> and <tt>\--best-memattr</tt>
 to select the best NUMA node among the local ones.

hwloc/memattrs.c

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2020-2023 Inria.  All rights reserved.
+ * Copyright © 2020-2024 Inria.  All rights reserved.
  * See COPYING in top-level directory.
  */
 
@@ -1806,6 +1806,12 @@ hwloc__apply_memory_tiers_subtypes(hwloc_topology_t topology,
       }
     }
   }
+  if (nr_tiers > 1) {
+    hwloc_obj_t root = hwloc_get_root_obj(topology);
+    char tmp[20];
+    snprintf(tmp, sizeof(tmp), "%u", nr_tiers);
+    hwloc__add_info_nodup(&root->infos, &root->infos_count, "MemoryTiersNr", tmp, 1);
+  }
 }
 
 int

hwloc/topology-xml.c

@@ -1,6 +1,6 @@
 /*
  * Copyright © 2009 CNRS
- * Copyright © 2009-2023 Inria.  All rights reserved.
+ * Copyright © 2009-2024 Inria.  All rights reserved.
  * Copyright © 2009-2011, 2020 Université Bordeaux
  * Copyright © 2009-2018 Cisco Systems, Inc.  All rights reserved.
  * See COPYING in top-level directory.

tests/hwloc/linux/64intel64-fakeKNL-SNC4-hybrid-msc.output

@@ -1,4 +1,4 @@
-Machine (P#0 total=12582912KB ClusterMode=SNC4 MemoryMode=Hybrid50 Backend=Linux OSName=Linux OSRelease=3.10.0-327.el7.x86_64 OSVersion="#1 SMP Thu Oct 29 17:29:29 EDT 2015" HostName=localhost.localdomain Architecture=x86_64)
+Machine (P#0 total=12582912KB ClusterMode=SNC4 MemoryMode=Hybrid50 Backend=Linux OSName=Linux OSRelease=3.10.0-327.el7.x86_64 OSVersion="#1 SMP Thu Oct 29 17:29:29 EDT 2015" HostName=localhost.localdomain Architecture=x86_64 MemoryTiersNr=2)
   Package L#0 (P#0 total=12582912KB CPUVendor=GenuineIntel CPUFamilyNumber=6 CPUModelNumber=87 CPUModel=06/57 CPUStepping=0)
     Group0(Cluster) L#0 (total=3145728KB)
       MemCache L#0 (total=1048576KB size=2097152KB linesize=64 ways=1 Inclusive=1)

tests/hwloc/linux/64intel64-fakeKNL-SNC4-hybrid.output

@@ -1,4 +1,4 @@
-Machine (P#0 total=12582912KB ClusterMode=SNC4 MemoryMode=Hybrid50 Backend=Linux OSName=Linux OSRelease=3.10.0-327.el7.x86_64 OSVersion="#1 SMP Thu Oct 29 17:29:29 EDT 2015" HostName=localhost.localdomain Architecture=x86_64)
+Machine (P#0 total=12582912KB ClusterMode=SNC4 MemoryMode=Hybrid50 Backend=Linux OSName=Linux OSRelease=3.10.0-327.el7.x86_64 OSVersion="#1 SMP Thu Oct 29 17:29:29 EDT 2015" HostName=localhost.localdomain Architecture=x86_64 MemoryTiersNr=2)
   Package L#0 (P#0 total=12582912KB CPUVendor=GenuineIntel CPUFamilyNumber=6 CPUModelNumber=87 CPUModel=06/57 CPUStepping=0)
     L3Cache(MemorySideCache) L#0 (total=3145728KB size=2097152KB linesize=64 ways=1 Inclusive=1)
       NUMANode(DRAM) L#0 (P#0 local=1048576KB total=1048576KB MemoryTier=1)

tests/hwloc/linux/fakeheteromemtiers.output

@@ -1,4 +1,4 @@
-Machine (P#0 total=6236076KB DMIProductName="Standard PC (i440FX + PIIX, 1996)" DMIProductVersion=pc-i440fx-7.0 DMIProductSerial= DMIChassisVendor=QEMU DMIChassisType=1 DMIChassisVersion=pc-i440fx-7.0 DMIChassisSerial= DMIChassisAssetTag= DMIBIOSVendor="EFI Development Kit II / OVMF" DMIBIOSVersion=0.0.0 DMIBIOSDate=02/06/2015 DMISysVendor=QEMU Backend=Linux LinuxCgroup=/ OSName=Linux OSRelease=5.18.0-rc4 OSVersion="#1 SMP PREEMPT_DYNAMIC Tue Apr 26 11:49:51 CEST 2022" HostName=efi Architecture=x86_64)
+Machine (P#0 total=6236076KB DMIProductName="Standard PC (i440FX + PIIX, 1996)" DMIProductVersion=pc-i440fx-7.0 DMIProductSerial= DMIChassisVendor=QEMU DMIChassisType=1 DMIChassisVersion=pc-i440fx-7.0 DMIChassisSerial= DMIChassisAssetTag= DMIBIOSVendor="EFI Development Kit II / OVMF" DMIBIOSVersion=0.0.0 DMIBIOSDate=02/06/2015 DMISysVendor=QEMU Backend=Linux LinuxCgroup=/ OSName=Linux OSRelease=5.18.0-rc4 OSVersion="#1 SMP PREEMPT_DYNAMIC Tue Apr 26 11:49:51 CEST 2022" HostName=efi Architecture=x86_64 MemoryTiersNr=3)
   Package L#0 (P#0 total=6236076KB CPUVendor=GenuineIntel CPUFamilyNumber=15 CPUModelNumber=107 CPUModel="QEMU Virtual CPU version 2.5+" CPUStepping=1)
     L3Cache L#0 (P#0 total=6236076KB size=16384KB linesize=64 ways=16)
       Group0 L#0 (total=3398608KB)

tests/hwloc/linux/fakememinitiators-1np2c+1npp+gi.output

@@ -1,4 +1,4 @@
-Machine (P#0 total=1951314696KB Backend=Linux LinuxCgroup=/)
+Machine (P#0 total=1951314696KB Backend=Linux LinuxCgroup=/ MemoryTiersNr=2)
   Package L#0 (P#0 total=974581080KB CPUModel="Intel(R) Xeon(R) Gold 6230 CPU @ 2.10GHz")
     NUMANode(NVM) L#2 (P#7 local=778043392KB total=778043392KB DAXDevice=dax0.0 DAXType=NVM DAXParent=LNXSYSTM:00/LNXSYBUS:00/ACPI0012:00/ndbus0/region0/dax0.1 MemoryTier=1)
     Group0 L#0 (total=97447340KB)

tests/hwloc/linux/nvidiagpunumanodes.kept.output

@@ -1,4 +1,4 @@
-Machine (P#0 total=358162944KB PlatformName=PowerNV PlatformModel="PowerNV 8335-GTW" Backend=Linux LinuxCgroup=/jjh OSName=Linux OSRelease=4.14.0-49.el7a.bz1553205.page_fault_hang.ppc64le OSVersion="#1 SMP Fri Mar 30 12:06:11 CDT 2018" HostName=c685f8n02 Architecture=ppc64le)
+Machine (P#0 total=358162944KB PlatformName=PowerNV PlatformModel="PowerNV 8335-GTW" Backend=Linux LinuxCgroup=/jjh OSName=Linux OSRelease=4.14.0-49.el7a.bz1553205.page_fault_hang.ppc64le OSVersion="#1 SMP Fri Mar 30 12:06:11 CDT 2018" HostName=c685f8n02 Architecture=ppc64le MemoryTiersNr=2)
   Package L#0 (P#0 total=177025024KB CPUModel="POWER9, altivec supported" CPURevision="2.1 (pvr 004e 1201)")
     NUMANode L#0 (P#0 local=129839104KB total=129839104KB MemoryTier=0)
     NUMANode(GPUMemory) L#1 (P#253 local=15728640KB total=15728640KB PCIBusID=0006:00:00.0 MemoryTier=1)

utils/hwloc/hwloc-info.c

@@ -705,6 +705,7 @@ hwloc_info_show_topology_infos(hwloc_topology_t topology)
     const char *infoname = root->infos[i].name;
     if (!strcmp(infoname, "Backend")
         || !strcmp(infoname, "SyntheticDescription")
+        || !strcmp(infoname, "MemoryTiersNr")
         || !strcmp(infoname, "LinuxCgroup")
         || !strcmp(infoname, "WindowsBuildEnvironment")
         || !strcmp(infoname, "OSName")