When a user tries to modify cpuidle or cpufreq properties on offline
CPUs, the tool returns success (exit status 0) but also does not provide
any warning message regarding offline cpus that may have been specified
but left unchanged. In case of all or a few CPUs being offline, it can be
difficult to keep track of which CPUs didn't get the new frequency or idle
state set. Silent failures are difficult to keep track of when there are a
huge number of CPUs on which the action is performed.
This patch adds helper functions to find both online and offline CPUs and
print them out accordingly.
We use these helper functions in cpuidle-set and cpufreq-set to print an
additional message if the user attempts to modify offline cpus.
Reported-by: Pavithra R. Prakash <pavrampu@in.ibm.com>
Signed-off-by: Brahadambal Srinivasan <latha@linux.vnet.ibm.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Based on 1 normalized pattern(s):
licensed under the terms of the gnu gpl license version 2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 62 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.929121379@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some operations, like frequency-set, need root privileges. However,
the way that this is detected is not correct. The getuid() is called,
while in fact geteuid() should be. This way we can allow
distributions or users to set SETUID flags on the cpupower binary if
they want to and let regular users change the cpu frequency governor.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Acked-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Example:
cpupower idle-set -d 3
will disable C-state 3 on all processors (set commands are active on
all CPUs by default), same as:
cpupower -c all idle-set -d 3
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Instead of printing something non-formatted to stdout, call
man(1) to show the man page for the proper subcommand.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
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>
Brahadambal Srinivasan