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Subject[PATCH 6/6] cpupower tools: Fix warning and a bug with the cpu package count
Date
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.
---
tools/power/cpupower/utils/helpers/topology.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/tools/power/cpupower/utils/helpers/topology.c b/tools/power/cpupower/utils/helpers/topology.c
index 4e2b583..fd3cc4d 100644
--- 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
+ becuase the primary sort of of the core_info structs 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
--
1.7.9.5


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