hwloc.ps: add --single-ancestor option

Signed-off-by: Valentin Hoyet <valentin.hoyet@inria.fr>
Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>

NEWS

@@ -34,6 +34,8 @@ Version 2.5.0
   + lstopo now has a --windows-processor-groups option on Windows.
   + hwloc-ps now has a --short-name option to avoid long/truncated
     command path.
+  + hwloc-ps now has a --single-ancestor option to return a single
+    (possibly too large) object where a process is bound.
 
 
 Version 2.4.1

contrib/completion/bash/hwloc

@@ -1,5 +1,5 @@
 #
-# Copyright © 2018-2020 Inria.  All rights reserved.
+# Copyright © 2018-2021 Inria.  All rights reserved.
 # See COPYING in top-level directory.
 #
 
@@ -468,6 +468,7 @@ _hwloc_ps(){
 		   -l --logical
 		   -p --physical
 		   -c --cpuset
+		   --single-ancestor
 		   -t --threads
 		   -e --get-last-cpu-location
 		   --pid-cmd

utils/hwloc/hwloc-ps.1in

@@ -55,6 +55,10 @@ Otherwise, show all threads inside each process where at least one
 thread is bound.
 This is currently only supported on Linux.
 .TP
+\fB\-\-single\-ancestor\fR
+When the object is bound to different objects,
+report their common ancestor (even if it may be larger than the actual binding).
+.TP
 \fB\-e\fR \fB\-\-get\-last\-cpu\-location\fR
 Report  the last processors where the process/thread ran.
 Note that the result may already be outdated when reported
@@ -129,6 +133,17 @@ If a process is bound, it appears in the default output:
     $ hwloc-ps
     4759	Core:0		myprogram
 
+If a process is bound on two cores of a larger package,
+the output will show these cores.
+Option \-\-single\-ancestor will rather return the package
+even if it is actually larger than the binding here
+(the process is not bound to Core:0 of Package:0):
+
+    $ hwloc-ps
+    4863        Core:1 Core:2   myprogram
+    $ hwloc-ps --single-ancestor
+    4863        Package:0       myprogram
+
 If a process is not bound but 3 of his 4 threads are bound,
 it only appears in the thread-aware output (or if explicitly selected):
 

utils/hwloc/hwloc-ps.c

@@ -32,6 +32,7 @@ static int show_threads = 0;
 static char *only_name = NULL;
 static int show_cpuset = 0;
 static int logical = 1;
+static int single_ancestor = 0;
 #define NO_ONLY_PID -1
 static long only_pid = NO_ONLY_PID;
 static long only_uid;
@@ -54,6 +55,7 @@ void usage(const char *name, FILE *where)
   fprintf (where, "  -l --logical       Use logical object indexes (default)\n");
   fprintf (where, "  -p --physical      Use physical object indexes\n");
   fprintf (where, "  -c --cpuset        Show cpuset instead of objects\n");
+  fprintf (where, "  --single-ancestor  Show a single ancestor containing the binding\n");
 #ifdef HWLOC_LINUX_SYS
   fprintf (where, "  -t --threads       Show threads\n");
 #endif
@@ -82,13 +84,25 @@ static void print_task(hwloc_topology_t topology,
   } else {
     hwloc_bitmap_t remaining = hwloc_bitmap_dup(cpuset);
     int first = 1;
-    while (!hwloc_bitmap_iszero(remaining)) {
-      char type[64];
-      unsigned idx;
+    char type[64];
+    unsigned idx;
+    if (single_ancestor) {
+      hwloc_obj_t obj = hwloc_get_obj_covering_cpuset(topology, cpuset);
+      while (obj->parent && hwloc_bitmap_isequal(obj->cpuset, obj->parent->cpuset) && !hwloc_obj_type_is_cache(obj->parent->type) )
+        obj = obj->parent;
+
+      hwloc_obj_type_snprintf(type, sizeof(type), obj, 1);
+      idx = logical ? obj->logical_index : obj->os_index;
+      if (idx == (unsigned) -1)
+        printf("%s", type);
+      else
+        printf("%s:%u", type, idx);
+    } else {
+     while (!hwloc_bitmap_iszero(remaining)) {
       hwloc_obj_t obj = hwloc_get_first_largest_obj_inside_cpuset(topology, remaining);
       /* don't show a cache if there's something equivalent and nicer */
       while (hwloc_obj_type_is_cache(obj->type) && obj->arity == 1)
-	obj = obj->first_child;
+        obj = obj->first_child;
       hwloc_obj_type_snprintf(type, sizeof(type), obj, 1);
       idx = logical ? obj->logical_index : obj->os_index;
       if (idx == (unsigned) -1)
@@ -97,6 +111,7 @@ static void print_task(hwloc_topology_t topology,
         printf("%s%s:%u", first ? "" : " ", type, idx);
       hwloc_bitmap_andnot(remaining, remaining, obj->cpuset);
       first = 0;
+     }
     }
     hwloc_bitmap_free(remaining);
   }
@@ -392,6 +407,8 @@ int main(int argc, char *argv[])
 #else
       fprintf (stderr, "Listing threads is currently only supported on Linux\n");
 #endif
+    } else if (!strcmp(argv[0], "--single-ancestor")) {
+      single_ancestor = 1;
     } else if (!strcmp(argv[0], "--pid")) {
       if (argc < 2) {
 	usage(callname, stderr);