gather-topology: bring back /proc/device-tree/cpus if --dt is given

May be useful for debugging what Linux exposes in sysfs, at least on ARM.

This reverts commit 9f37aae
and adds conditionals on top of the old code.

Signed-off-by: Brice Goglin <[email protected]>

Author: bgoglin

contrib/completion/bash/hwloc

@@ -555,6 +555,7 @@ complete -F _hwloc_gather_cpuid hwloc-gather-cpuid
 _hwloc_gather_topology(){
     local OPTIONS=(--io
 		   --dmi
+		   --dt
 		   --no-cpuid
 		   --keep
 		   --version

utils/hwloc/hwloc-gather-topology.1in

@@ -1,6 +1,6 @@
 .\" -*- nroff -*-
 .\" Copyright © 2010 Jirka Hladky
-.\" Copyright © 2010-2021 Inria.  All rights reserved.
+.\" Copyright © 2010-2023 Inria.  All rights reserved.
 .\" See COPYING in top-level directory.
 .TH HWLOC-GATHER-TOPOLOGY "1" "%HWLOC_DATE%" "%PACKAGE_VERSION%" "%PACKAGE_NAME%"
 .SH NAME
@@ -30,6 +30,11 @@ Also gather DMI/SMBIOS related files.
 The gathering requires root access, and the dmi-sysfs kernel module should be loaded.
 .
 .TP
+\fB\-\-dt\fR
+Also gather Device-Tree CPU files. These files aren't needed for hwloc,
+but they may be used for debugging what Linux exposes in /sys.
+.
+.TP
 \fB\-\-no\-cpuid\fR
 Do not gather x86 CPUID dump using \fIhwloc\-gather\-cpuid\fR.
 .

utils/hwloc/hwloc-gather-topology.in

@@ -31,6 +31,7 @@ unalias ls
 gathercpuid=1
 gatherio=0
 gatherdmi=0
+gatherdt=0
 keep=0
 
 if [ ! -x "$lstopo" ]
@@ -52,6 +53,7 @@ usage()
    echo "Options:"
    echo "  --io        Gather I/O files (takes much longer and generates much larger tarball)"
    echo "  --dmi       Gather SMBIOS files. Works only when run as root. Requires dmi-sysfs kernel module"
+   echo "  --dt        Gather Device-Tree CPU files under /proc/device-tree/cpus"
    echo "  --no-cpuid  Do not gather x86 CPUID using hwloc-gather-cpuid"
    echo "  --keep      Keep the temporary copy of dumped files"
    echo "  --version   Report version and exit"
@@ -64,6 +66,7 @@ while [ x`echo "$1" | cut -c1` = x- ] ; do
   case $1 in
   --io) gatherio=1;;
   --dmi) gatherdmi=1;;
+  --dt) gatherdt=1;;
   --no-cpuid) gathercpuid=0;;
   --keep) keep=1;;
   --version) echo `basename $0`" $HWLOC_VERSION"; exit 0;;
@@ -87,6 +90,9 @@ fi
 if [ x$gatherdmi = x0 ]; then
   echo "DMI files won't be saved (--dmi not given)."
 fi
+if [ x$gatherdt = x0 ]; then
+  echo "Device-Tree CPU files won't be saved (--dt not given)."
+fi
 
 echo
 echo "*** Note that this tool may be slow on large nodes or when I/O is enabled. ***"
@@ -249,6 +255,11 @@ savedir "$destdir/$basename" /sys/devices/virtual/dmi/id/
 # Gather hugepage information
 savedir "$destdir/$basename" /sys/kernel/mm/hugepages/
 
+if [ x$gatherdt = x1 ]; then
+  # Gather device-tree cpus
+  savedir "$destdir/$basename" /proc/device-tree/cpus/
+fi
+
 # Gather the default /var/run/hwloc (in case it was created by a system-wide hwloc-dump-hwdata)
 if test -d /var/run/hwloc; then
   savedir "$destdir/$basename" /var/run/hwloc