cpupower tools: Fix warning and a bug with the cpu package count

The pkgs member of cpupower_topology is being used as the number of
cpu packages. As the comment in get_cpu_topology notes, the package ids
are not guaranteed to be contiguous. So, simply setting pkgs to the value
of the highest physical_package_id doesn't actually provide a count of
the number of cpu packages. Instead, calculate pkgs by setting it to
the number of distinct physical_packge_id values which is pretty easy
to do after the core_info structs are sorted. Calculating pkgs this
way also has the nice benefit of getting rid of a sign comparison warning
that GCC 4.6 was reporting.

Signed-off-by: Palmer Cox <p@lmercox.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/tools/power/cpupower/utils/helpers/topology.c b/tools/power/cpupower/utils/helpers/topology.c
index 4e2b583..c13120a 100644 (file)
--- a/tools/power/cpupower/utils/helpers/topology.c
+++ b/tools/power/cpupower/utils/helpers/topology.c
@@ -64,7 +64,7 @@ static int __compare(const void *t1, const void *t2)
  */
 int get_cpu_topology(struct cpupower_topology *cpu_top)
 {
-       int cpu, cpus = sysconf(_SC_NPROCESSORS_CONF);
+       int cpu, last_pkg, cpus = sysconf(_SC_NPROCESSORS_CONF);
 
        cpu_top->core_info = malloc(sizeof(struct cpuid_core_info) * cpus);
        if (cpu_top->core_info == NULL)
@@ -78,20 +78,28 @@ int get_cpu_topology(struct cpupower_topology *cpu_top)
                        "physical_package_id",
                        &(cpu_top->core_info[cpu].pkg)) < 0)
                        return -1;
-               if ((int)cpu_top->core_info[cpu].pkg != -1 &&
-                   cpu_top->core_info[cpu].pkg > cpu_top->pkgs)
-                       cpu_top->pkgs = cpu_top->core_info[cpu].pkg;
                if(sysfs_topology_read_file(
                        cpu,
                        "core_id",
                        &(cpu_top->core_info[cpu].core)) < 0)
                        return -1;
        }
-       cpu_top->pkgs++;
 
        qsort(cpu_top->core_info, cpus, sizeof(struct cpuid_core_info),
              __compare);
 
+       /* Count the number of distinct pkgs values. This works
+          because the primary sort of the core_info struct was just
+          done by pkg value. */
+       last_pkg = cpu_top->core_info[0].pkg;
+       for(cpu = 1; cpu < cpus; cpu++) {
+               if(cpu_top->core_info[cpu].pkg != last_pkg) {
+                       last_pkg = cpu_top->core_info[cpu].pkg;
+                       cpu_top->pkgs++;
+               }
+       }
+       cpu_top->pkgs++;
+
        /* Intel's cores count is not consecutively numbered, there may
         * be a core_id of 3, but none of 2. Assume there always is 0
         * Get amount of cores by counting duplicates in a package