Merge: cpupower: Update libcpupower Python bindings

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-10/-/merge_requests/1245

Description: include updates a future MR will need to build the bindings.

JIRA: https://issues.redhat.com/browse/RHEL-91191

Signed-off-by: John B. Wyatt IV <jwyatt@redhat.com>

Approved-by: John Kacur <jkacur@redhat.com>
Approved-by: David Arcari <darcari@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Scott Weaver <scweaver@redhat.com>

Author: swvrrh

tools/power/cpupower/bindings/python/Makefile

@@ -1,24 +1,25 @@
 # SPDX-License-Identifier: GPL-2.0-only
 # Makefile for libcpupower's Python bindings
 #
-# This Makefile expects you have already run the makefile for cpupower to build
-# the .o files in the lib directory for the bindings to be created.
+# This Makefile expects you have already run `make install-lib` in the lib
+# directory for the bindings to be created.
 
-CC := gcc
+CC ?= gcc
+# CFLAGS ?=
+LDFLAGS ?= -lcpupower
 HAVE_SWIG := $(shell if which swig >/dev/null 2>&1; then echo 1; else echo 0; fi)
 HAVE_PYCONFIG := $(shell if which python-config >/dev/null 2>&1; then echo 1; else echo 0; fi)
 
-LIB_DIR := ../../lib
-PY_INCLUDE = $(firstword $(shell python-config --includes))
-OBJECTS_LIB = $(wildcard $(LIB_DIR)/*.o)
+PY_INCLUDE ?= $(firstword $(shell python-config --includes))
+INSTALL_DIR ?= $(shell python3 -c "import site; print(site.getsitepackages()[0])")
 
 all: _raw_pylibcpupower.so
 
 _raw_pylibcpupower.so: raw_pylibcpupower_wrap.o
-	$(CC) -shared $(OBJECTS_LIB) raw_pylibcpupower_wrap.o -o _raw_pylibcpupower.so
+	$(CC) -shared $(LDFLAGS) raw_pylibcpupower_wrap.o -o _raw_pylibcpupower.so
 
 raw_pylibcpupower_wrap.o: raw_pylibcpupower_wrap.c
-	$(CC) -fPIC -c raw_pylibcpupower_wrap.c $(PY_INCLUDE)
+	$(CC) $(CFLAGS) $(PY_INCLUDE) -fPIC -c raw_pylibcpupower_wrap.c
 
 raw_pylibcpupower_wrap.c: raw_pylibcpupower.swg
 ifeq ($(HAVE_SWIG),0)
@@ -28,6 +29,15 @@ else ifeq ($(HAVE_PYCONFIG),0)
 endif
 	swig -python raw_pylibcpupower.swg
 
+# Only installs the Python bindings
+install: _raw_pylibcpupower.so
+	install -D _raw_pylibcpupower.so $(INSTALL_DIR)/_raw_pylibcpupower.so
+	install -D raw_pylibcpupower.py $(INSTALL_DIR)/raw_pylibcpupower.py
+
+uninstall:
+	rm -f $(INSTALL_DIR)/_raw_pylibcpupower.so
+	rm -f $(INSTALL_DIR)/raw_pylibcpupower.py
+
 # Will only clean the bindings folder; will not clean the actual cpupower folder
 clean:
 	rm -f raw_pylibcpupower.py raw_pylibcpupower_wrap.c raw_pylibcpupower_wrap.o _raw_pylibcpupower.so

tools/power/cpupower/bindings/python/README

@@ -5,18 +5,21 @@ libcpupower (aside from the libcpupower object files).
 requirements
 ------------
 
-* You need the object files in the libcpupower directory compiled by
-cpupower's makefile.
+* If you are building completely from upstream; please install libcpupower by
+running `make install-lib` within the cpupower directory. This installs the
+libcpupower.so file and symlinks needed. Otherwise, please make sure a symlink
+to libcpupower.so exists in your library path from your distribution's
+packages.
 * The SWIG program must be installed.
-* The Python's development libraries installed.
+* The Python's development libraries must be installed.
 
 Please check that your version of SWIG is compatible with the version of Python
 installed on your machine by checking the SWIG changelog on their website.
 https://swig.org/
 
 Note that while SWIG itself is GPL v3+ licensed; the resulting output,
-the bindings code: is permissively licensed + the license of libcpupower's .o
-files. For these bindings that means GPL v2.
+the bindings code: is permissively licensed + the license of libcpupower's
+library files. For these bindings that means GPL v2.
 
 Please see https://swig.org/legal.html and the discussion [1] for more details.
 
@@ -48,6 +51,31 @@ To run the test script:
 $ python test_raw_pylibcpupower.py
 
 
+developing/using the bindings directly
+--------------------------------------
+
+You need to add the Python bindings directory to your $PYTHONPATH.
+
+You would set the path in the Bash terminal or in the Bash profile:
+
+PYTHONPATH=~/linux/tools/power/cpupower/bindings/python:$PYTHONPATH
+
+This allows you to set a specific repo of the bindings to use.
+
+
+installing/uninstalling
+-----------------------
+
+Python uses a system specific site-packages folder to look up modules to import
+by default. You do not need to install cpupower to use the SWIG bindings.
+
+You can install and uninstall the bindings to the site-packages with:
+
+sudo make install
+
+sudo make uninstall
+
+
 credits
 -------
 

tools/power/cpupower/bindings/python/raw_pylibcpupower.swg

@@ -134,6 +134,9 @@ void cpufreq_put_stats(struct cpufreq_stats *stats);
 
 unsigned long cpufreq_get_transitions(unsigned int cpu);
 
+char *cpufreq_get_energy_performance_preference(unsigned int cpu);
+void cpufreq_put_energy_performance_preference(char *ptr);
+
 int cpufreq_set_policy(unsigned int cpu, struct cpufreq_policy *policy);
 
 int cpufreq_modify_policy_min(unsigned int cpu, unsigned long min_freq);
@@ -160,6 +163,8 @@ int cpuidle_state_disable(unsigned int cpu, unsigned int idlestate,
 				   unsigned int disable);
 unsigned long cpuidle_state_latency(unsigned int cpu,
 						unsigned int idlestate);
+unsigned long cpuidle_state_residency(unsigned int cpu,
+						unsigned int idlestate);
 unsigned long cpuidle_state_usage(unsigned int cpu,
 					unsigned int idlestate);
 unsigned long long cpuidle_state_time(unsigned int cpu,

tools/power/cpupower/bindings/python/test_raw_pylibcpupower.py

@@ -15,22 +15,38 @@
     print(f"cstate count error: return code: {cpu_cstates_count}")
 
 """
-Disable cstate (will fail if the above is 0, ex: a virtual machine)
+Disable cstate (will fail if the above returns is under 1, ex: a virtual machine)
 """
 cstate_disabled = p.cpuidle_state_disable(0, 0, 1)
-if cpu_cstates_count == 0:
-    print(f"CPU 0 has {cpu_cstates_count} c-states")
-else:
-    print(f"cstate count error: return code: {cpu_cstates_count}")
 
 match cstate_disabled:
     case 0:
         print(f"CPU state disabled")
     case -1:
         print(f"Idlestate not available")
+    case -2:
+        print(f"Disabling is not supported by the kernel")
+    case -3:
+        print(f"No write access to disable/enable C-states: try using sudo")
     case _:
-        print(f"Not documented")
+        print(f"Not documented: {cstate_disabled}")
+
+"""
+Test cstate is disabled
+"""
+is_cstate_disabled = p.cpuidle_is_state_disabled(0, 0)
 
+match is_cstate_disabled:
+    case 1:
+        print(f"CPU is disabled")
+    case 0:
+        print(f"CPU is enabled")
+    case -1:
+        print(f"Idlestate not available")
+    case -2:
+        print(f"Disabling is not supported by kernel")
+    case _:
+        print(f"Not documented: {is_cstate_disabled}")
 
 # Pointer example