From: John B. Wyatt IV Date: Wed, 5 Mar 2025 21:08:59 +0000 (-0500) Subject: cpupower: Implement CPU physical core querying X-Git-Tag: v6.15-rc1~191^2~5^2~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f89cb9cba7a2557db676b507dd181d9751c7d11d;p=thirdparty%2Flinux.git cpupower: Implement CPU physical core querying This patch is also an issue report. get_cpu_topology will always save into cpupower_topology a cores size of 0. The code to handle this looks like it was commented out, and what is commented out is missing a curly bracket. https://elixir.bootlin.com/linux/v6.13.5/source/tools/power/cpupower/lib/cpupower.c#L206-L212 Inspiration was taken from psutil to implement this by querying core_cpu_list. Instead of using a hashmap, I used a sorted array, and counted the number of valid unique strings. The counting of this takes place before the qsort for .pkg as the following code says it is dependent on the order of that sort. The previous code claimed Intel CPUs are not numbered correctly. I was not able to reproduce that issue and removed that comment and the code. This commit was tested with the libcpupower SWIG Python bindings and performed correctly on 4 different setups. The most notable is the Framework Intel laptop; a hybrid system of 4 P cores (8 threads) and 8 E cores (8 threads). The 4 setups: A 4 core virt-manager VM running Fedora 41 4c/4t (specs not listed) was tested as a sanity test for VMs. A Lenovo Ryzen 7 Pro 7840HS 8c/16t. A Supermico Intel(R) Xeon(R) Gold 6330 CPU w/ 56c/112t with 2 CPU sockets. A Framework 12th Gen Intel(R) Core(TM) i5-1240P with hybrid cores. CPU(s): 16 On-line CPU(s) list: 0-15 Vendor ID: AuthenticAMD Model name: AMD Ryzen 7 PRO 7840HS w/ Radeon 780M Graphics CPU family: 25 Model: 116 Thread(s) per core: 2 Core(s) per socket: 8 Socket(s): 1 Stepping: 1 CPU(s): 112 On-line CPU(s) list: 0-111 Vendor ID: GenuineIntel BIOS Vendor ID: Intel(R) Corporation Model name: Intel(R) Xeon(R) Gold 6330 CPU @ 2.00GHz BIOS Model name: Intel(R) Xeon(R) Gold 6330 CPU @ 2.00GHz CPU @ 2.0GHz BIOS CPU family: 179 CPU family: 6 Model: 106 Thread(s) per core: 2 Core(s) per socket: 28 Socket(s): 2 Stepping: 6 CPU(s): 16 On-line CPU(s) list: 0-15 Vendor ID: GenuineIntel Model name: 12th Gen Intel(R) Core(TM) i5-1240P CPU family: 6 Model: 154 Thread(s) per core: 2 Core(s) per socket: 12 Socket(s): 1 Stepping: 3 Link: https://lore.kernel.org/r/20250305210901.24177-1-jwyatt@redhat.com Signed-off-by: "John B. Wyatt IV" Signed-off-by: "John B. Wyatt IV" Signed-off-by: Shuah Khan --- diff --git a/tools/power/cpupower/lib/cpupower.c b/tools/power/cpupower/lib/cpupower.c index 7a2ef691b20e1..ce8dfb8e46abd 100644 --- a/tools/power/cpupower/lib/cpupower.c +++ b/tools/power/cpupower/lib/cpupower.c @@ -10,6 +10,7 @@ #include #include #include +#include #include "cpupower.h" #include "cpupower_intern.h" @@ -150,15 +151,25 @@ static int __compare(const void *t1, const void *t2) return 0; } +static int __compare_core_cpu_list(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; + + return strcmp(top1->core_cpu_list, top2->core_cpu_list); +} + /* * 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 + * Array is sorted after ->cpu_smt_list ->pkg, ->core */ int get_cpu_topology(struct cpupower_topology *cpu_top) { int cpu, last_pkg, cpus = sysconf(_SC_NPROCESSORS_CONF); + char path[SYSFS_PATH_MAX]; + char *last_cpu_list; cpu_top->core_info = malloc(sizeof(struct cpuid_core_info) * cpus); if (cpu_top->core_info == NULL) @@ -183,6 +194,34 @@ int get_cpu_topology(struct cpupower_topology *cpu_top) cpu_top->core_info[cpu].core = -1; continue; } + if (cpu_top->core_info[cpu].core == -1) { + strncpy(cpu_top->core_info[cpu].core_cpu_list, "-1", CPULIST_BUFFER); + continue; + } + snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/topology/%s", + cpu, "core_cpus_list"); + if (cpupower_read_sysfs( + path, + cpu_top->core_info[cpu].core_cpu_list, + CPULIST_BUFFER) < 1) { + printf("Warning CPU%u has a 0 size core_cpus_list string", cpu); + } + } + + /* Count the number of distinct cpu lists to get the physical core + * count. + */ + qsort(cpu_top->core_info, cpus, sizeof(struct cpuid_core_info), + __compare_core_cpu_list); + + last_cpu_list = cpu_top->core_info[0].core_cpu_list; + cpu_top->cores = 1; + for (cpu = 1; cpu < cpus; cpu++) { + if (strcmp(cpu_top->core_info[cpu].core_cpu_list, last_cpu_list) != 0 && + cpu_top->core_info[cpu].pkg != -1) { + last_cpu_list = cpu_top->core_info[cpu].core_cpu_list; + cpu_top->cores++; + } } qsort(cpu_top->core_info, cpus, sizeof(struct cpuid_core_info), @@ -203,13 +242,6 @@ int get_cpu_topology(struct cpupower_topology *cpu_top) if (!(cpu_top->core_info[0].pkg == -1)) 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 - 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; } diff --git a/tools/power/cpupower/lib/cpupower.h b/tools/power/cpupower/lib/cpupower.h index e4e4292eacec6..2e67a080f2034 100644 --- a/tools/power/cpupower/lib/cpupower.h +++ b/tools/power/cpupower/lib/cpupower.h @@ -2,6 +2,8 @@ #ifndef __CPUPOWER_CPUPOWER_H__ #define __CPUPOWER_CPUPOWER_H__ +#define CPULIST_BUFFER 5 + struct cpupower_topology { /* Amount of CPU cores, packages and threads per core in the system */ unsigned int cores; @@ -16,6 +18,7 @@ struct cpuid_core_info { int pkg; int core; int cpu; + char core_cpu_list[CPULIST_BUFFER]; /* flags */ unsigned int is_online:1;