cpupowerutils - cpufrequtils extended with quite some features

CPU power consumption vs performance tuning is no longer
limited to CPU frequency switching anymore: deep sleep states,
traditional dynamic frequency scaling and hidden turbo/boost
frequencies are tied close together and depend on each other.
The first two exist on different architectures like PPC, Itanium and
ARM, the latter (so far) only on X86. On X86 the APU (CPU+GPU) will
only run most efficiently if CPU and GPU has proper power management
in place.

Users and Developers want to have *one* tool to get an overview what
their system supports and to monitor and debug CPU power management
in detail. The tool should compile and work on as many architectures
as possible.

Once this tool stabilizes a bit, it is intended to replace the
Intel-specific tools in tools/power/x86

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

1 files changed, 108 insertions, 0 deletions

diff --git a/tools/power/cpupower/utils/helpers/topology.c b/tools/power/cpupower/utils/helpers/topology.c
new file mode 100644
index 00000000000..5ad842b956b
--- /dev/null
+++ b/tools/power/cpupower/utils/helpers/topology.c
@@ -0,0 +1,108 @@
+/*
+ *  (C) 2010,2011       Thomas Renninger <trenn@suse.de>, Novell Inc.
+ *
+ *  Licensed under the terms of the GNU GPL License version 2.
+ *
+ * ToDo: Needs to be done more properly for AMD/Intel specifics
+ */
+
+/* Helper struct for qsort, must be in sync with cpupower_topology.cpu_info */
+/* Be careful: Need to pass unsigned to the sort, so that offlined cores are
+   in the end, but double check for -1 for offlined cpus at other places */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#include <helpers/helpers.h>
+#include <helpers/sysfs.h>
+
+/* returns -1 on failure, 0 on success */
+int sysfs_topology_read_file(unsigned int cpu, const char *fname)
+{
+ 	unsigned long value;
+	char linebuf[MAX_LINE_LEN];
+	char *endp;
+	char path[SYSFS_PATH_MAX];
+
+	snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/topology/%s",
+			 cpu, fname);
+	if (sysfs_read_file(path, linebuf, MAX_LINE_LEN) == 0 )
+		return -1;
+	value = strtoul(linebuf, &endp, 0);
+	if ( endp == linebuf || errno == ERANGE )
+		return -1;
+	return value;
+}
+
+struct cpuid_core_info {
+	unsigned int pkg;
+	unsigned int thread;
+	unsigned int cpu;
+};
+
+static int __compare(const void *t1, const void *t2)
+{
+	struct cpuid_core_info *top1 = (struct cpuid_core_info *)t1;
+	struct cpuid_core_info *top2 = (struct cpuid_core_info *)t2;
+	if (top1->pkg < top2->pkg)
+		return -1;
+	else if (top1->pkg > top2->pkg)
+		return 1;
+	else if (top1->thread < top2->thread)
+		return -1;
+	else if (top1->thread > top2->thread)
+		return 1;
+	else if (top1->cpu < top2->cpu)
+		return -1;
+	else if (top1->cpu > top2->cpu)
+		return 1;
+	else
+		return 0;
+}
+
+/*
+ * Returns amount of cpus, negative on error, cpu_top must be
+ * passed to cpu_topology_release to free resources
+ *
+ * Array is sorted after ->pkg, ->core, then ->cpu
+ */
+int get_cpu_topology(struct cpupower_topology *cpu_top)
+{
+	int cpu, cpus = sysconf(_SC_NPROCESSORS_CONF);
+
+	cpu_top->core_info = malloc(sizeof(struct cpupower_topology) * cpus);
+	if (cpu_top->core_info == NULL)
+		return -ENOMEM;
+	cpu_top->pkgs = cpu_top->cores = 0;
+	for (cpu = 0; cpu < cpus; cpu++) {
+		cpu_top->core_info[cpu].pkg =
+			sysfs_topology_read_file(cpu, "physical_package_id");
+		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;
+		cpu_top->core_info[cpu].core =
+			sysfs_topology_read_file(cpu, "core_id");
+		cpu_top->core_info[cpu].cpu = cpu;
+	}
+	cpu_top->pkgs++;
+
+	qsort(cpu_top->core_info, cpus, sizeof(struct cpuid_core_info),
+	      __compare);
+
+	/* 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
+	for (cpu = 0; cpu_top->core_info[cpu].pkg = 0 && cpu < cpus; cpu++) {
+		if (cpu_top->core_info[cpu].core == 0)
+	cpu_top->cores++;
+	*/
+	return cpus;
+}
+
+void cpu_topology_release(struct cpupower_topology cpu_top)
+{
+	free(cpu_top.core_info);
+}