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>
If an MSR based monitor is run in parallel this is not needed. This is the
default case on all/most Intel machines.
But when only sysfs info is read via cpupower monitor -m Idle_Stats (typically
the case for non root users) or when other monitors are PCI based (AMD),
Idle_Stats, read from sysfs can be totally bogus:
cpupower monitor -m Idle_Stats
PKG |CORE|CPU | POLL | C1-N | C3-N | C6-N
0| 0| 0| 0.00| 0.00| 0.24| 99.81
0| 0| 32| 0.00| 0.00| 0.00| 100.7
...
0| 17| 20| 0.00| 0.00| 0.00| 173.1
0| 17| 52| 0.00| 0.00| 0.07| 173.0
0| 18| 68| 0.00| 0.00| 0.00| 0.00
0| 18| 76| 0.00| 0.00| 0.00| 0.00
...
With the -c option all cores are woken up and the kernel
did update cpuidle statistics before reading out sysfs.
This causes some overhead. Therefore avoid if possible, use
if needed:
cpupower monitor -c -m Idle_Stats
PKG |CORE|CPU | POLL | C1-N | C3-N | C6-N
0| 0| 0| 0.00| 0.00| 0.00| 100.2
0| 0| 32| 0.00| 0.00| 0.00| 100.2
...
0| 8| 8| 0.00| 0.00| 0.00| 99.82
0| 8| 40| 0.00| 0.00| 0.00| 99.81
0| 9| 24| 0.00| 0.00| 0.00| 100.3
0| 9| 56| 0.00| 0.00| 0.00| 100.2
0| 16| 4| 0.00| 0.00| 0.00| 99.75
0| 16| 36| 0.00| 0.00| 0.00| 99.38
...
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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>
Thomas Gleixner