[Xen-devel] [PATCH] Supporting reading of system information from BIOS.

[Rita Sinha <rita.sinha89@xxxxxxxxx>]

This patch is in response to 
http://wiki.xenproject.org/wiki/Outreach_Program_Projects#CPU.2FRAM.2FPCI_diagram_tool
 project for applying to OPW-Round9.It adds support for reading system 
architecture information from BIOS rather than from sysfs and proc interfaces 
since in a virtualisation enviroment, some of this information is no longer 
accurate, particularly any information based around numbers of cpus.
---
 dmidecode.pl | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 dmidecode.pl

diff --git a/dmidecode.pl b/dmidecode.pl
new file mode 100644
index 0000000..76fdf78
--- /dev/null
+++ b/dmidecode.pl
@@ -0,0 +1,51 @@
+#!/usr/bin/perl
+
+# dmidecode.pl - a script to read the system architecture information
+# directly from the BIOS.  Only for Linux.
+#
+# Rita Sinha (rita.sinha89@xxxxxxxxx)
+# OPW Program-Round9
+# 14/10/14
+
+`id -u` == 0 || die "must be run as root";
+
+open(DmiFh, "/usr/sbin/dmidecode |") or
+  die "problem running dmidecode";
+$DmiNumProcs = 0;
+$DmiNumSockets = 0;
+while(<DmiFh>)
+  {
+    next unless /Central Processor/;
+    # We've found a processor (or at least a socket), keep going
+    while(<DmiFh>)
+       {
+         # Keep walking the dmidecode output to find out if
+         # the socket has a processor in it.
+         last if /^Handle/;
+         next unless /Status/;
+         $DmiNumSockets += 1;
+         /Populated/ and $DmiNumProcs += 1;
+         last;
+       }
+  }
+close DmiFh;
+
+open(CpuInfoFh, "/proc/cpuinfo") || die "failed to open /proc/cpuinfo!";
+$CpuInfoNumProcs = 0;
+while(<CpuInfoFh>)
+  {
+    next unless /^processor.*:/;
+    ($CpuInfoNumProcs) += (/^processor.*: (\d+)/);
+  }
+close CpuInfoFh;
+
+if ( $DmiNumProcs != $CpuInfoNumProcs )
+  {
+    print "Warning: dmidecode reports $DmiNumProcs processors, kernel reports 
$CpuInfoNumProcs processors.\n";
+  }
+
+if ( $DmiNumProcs != $DmiNumSockets )
+  {
+    print "Info: dmidecode reports $DmiNumSockets cpu sockets, but only 
$DmiNumProcs processors.\n";
+  }
+
-- 
1.8.3.1

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