linux.git/tools/power/cpupower, branch v5.5

cpupower: ToDo: Update ToDo with ideas for per_cpu_schedule handling

2019-11-06T00:23:23+00:00

Based on Thomas Renninger's feedback/ideas. Re-structure the code
to better handle the per_cpu_schedule mechanism which was introduced
when adding support for AMD Zen based processors.

Signed-off-by: Janakarajan Natarajan 
Acked-by: Thomas Renninger 
Signed-off-by: Shuah Khan

cpupower: mperf_monitor: Update cpupower to use the RDPRU instruction

2019-11-06T00:22:56+00:00

AMD Zen 2 introduces the RDPRU instruction which can be used to access some
processor registers which are typically only accessible in privilege level
0. ECX specifies the register to read and EDX:EAX will contain the value read.

ECX: 0 - Register MPERF
     1 - Register APERF

This has the added advantage of not having to use the msr module, since the
userspace to kernel transitions which occur during each read_msr() might
cause APERF and MPERF to go out of sync.

Signed-off-by: Janakarajan Natarajan 
Acked-by: Thomas Renninger 
Signed-off-by: Shuah Khan

cpupower: mperf_monitor: Introduce per_cpu_schedule flag

2019-11-06T00:22:46+00:00

The per_cpu_schedule flag is used to move the cpupower process to the cpu
on which we are looking to read the APERF/MPERF registers.

This prevents IPIs from being generated by read_msr()s as we are already
on the cpu of interest.

Ex: If cpupower is running on CPU 0 and we execute

    read_msr(20, MSR_APERF, val) then,
    read_msr(20, MSR_MPERF, val)

    the msr module will generate an IPI from CPU 0 to CPU 20 to query
    for the MSR_APERF and then the MSR_MPERF in separate IPIs.

This delay, caused by IPI latency, between reading the APERF and MPERF
registers may cause both of them to go out of sync.

The use of the per_cpu_schedule flag reduces the probability of this
from happening. It comes at the cost of a negligible increase in cpu
consumption caused by the migration of cpupower across each of the
cpus of the system.

Signed-off-by: Janakarajan Natarajan 
Acked-by: Thomas Renninger 
Signed-off-by: Shuah Khan

cpupower: Move needs_root variable into a sub-struct

2019-11-06T00:22:01+00:00

Move the needs_root variable into a sub-struct. This is in preparation
for adding a new flag for cpuidle_monitor.

Update all uses of the needs_root variable to reflect this change.

Signed-off-by: Janakarajan Natarajan 
Acked-by: Thomas Renninger 
Signed-off-by: Shuah Khan

cpupower : Handle set and info subcommands correctly

2019-11-04T20:11:57+00:00

Cpupower tool has set and info options which are being used only by
x86 machines. This patch removes support for these two subcommands
from cpupower utility for POWER. Thus, these two subcommands will now be
available only for intel.
This removes the ambiguous error message while using set option in case
of using non-intel systems.

Without this patch on a POWER system:

root@ubuntu:~# cpupower info
System does not support Intel's performance bias setting

root@ubuntu:~# cpupower set -b 10
Error setting perf-bias value on CPU

With this patch on a POWER box:

root@ubuntu:~# cpupower info
Subcommand not supported on POWER

Same result for set subcommand.
This patch does not affect results on a intel box.

Signed-off-by: Abhishek Goel 
Acked-by: Thomas Renninger 
Reviewed-by: Shuah Khan 
Signed-off-by: Shuah Khan

tools/power/cpupower: Fix initializer override in hsw_ext_cstates

2019-10-01T23:38:12+00:00

When building cpupower with clang, the following warning appears:

 utils/idle_monitor/hsw_ext_idle.c:42:16: warning: initializer overrides
 prior initialization of this subobject [-Winitializer-overrides]
                 .desc                   = N_("Processor Package C2"),
                                              ^~~~~~~~~~~~~~~~~~~~~~
 ./utils/helpers/helpers.h:25:33: note: expanded from macro 'N_'
 #define N_(String) gettext_noop(String)
                                 ^~~~~~
 ./utils/helpers/helpers.h:23:30: note: expanded from macro
 'gettext_noop'
 #define gettext_noop(String) String
                              ^~~~~~
 utils/idle_monitor/hsw_ext_idle.c:41:16: note: previous initialization
 is here
                 .desc                   = N_("Processor Package C9"),
                                              ^~~~~~~~~~~~~~~~~~~~~~
 ./utils/helpers/helpers.h:25:33: note: expanded from macro 'N_'
 #define N_(String) gettext_noop(String)
                                 ^~~~~~
 ./utils/helpers/helpers.h:23:30: note: expanded from macro
 'gettext_noop'
 #define gettext_noop(String) String
                             ^~~~~~
 1 warning generated.

This appears to be a copy and paste or merge mistake because the name
and id fields both have PC9 in them, not PC2. Remove the second
assignment to fix the warning.

Fixes: 7ee767b69b68 ("cpupower: Add Haswell family 0x45 specific idle monitor to show PC8,9,10 states")
Link: https://github.com/ClangBuiltLinux/linux/issues/718
Signed-off-by: Nathan Chancellor 
Signed-off-by: Shuah Khan

cpupower: update German translation

2019-08-29T16:18:52+00:00

Update the German translation of cpupower, and change the encoding
to UTF-8.

[skhan@linuxfoundation.org: fix merge conflicts]
Signed-off-by: Benjamin Weis 
Acked-by: Dominik Brodowski 
Signed-off-by: Shuah Khan

tools/power/cpupower: fix 64bit detection when cross-compiling

2019-08-29T15:50:54+00:00

When cross-compiling cpupower, 64bit detection is done with the host
compiler instead of the cross-compiler and libcpupower.so.0 ends up in
/usr/lib64 instead of /usr/lib for 32bit target.  Fix this by moving
64bit detection after CC is defined.

Signed-off-by: Sébastien Szymanski 
Signed-off-by: Shuah Khan

cpupower: Add missing newline at end of file

2019-08-29T15:49:26+00:00

"git diff" says:

    \ No newline at end of file

after modifying the files.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Shuah Khan

kbuild: create *.mod with full directory path and remove MODVERDIR

2019-07-17T17:19:31+00:00

While descending directories, Kbuild produces objects for modules,
but do not link final *.ko files; it is done in the modpost.

To keep track of modules, Kbuild creates a *.mod file in $(MODVERDIR)
for every module it is building. Some post-processing steps read the
necessary information from *.mod files. This avoids descending into
directories again. This mechanism was introduced in 2003 or so.

Later, commit 551559e13af1 ("kbuild: implement modules.order") added
modules.order. So, we can simply read it out to know all the modules
with directory paths. This is easier than parsing the first line of
*.mod files.

$(MODVERDIR) has a flat directory structure, that is, *.mod files
are named only with base names. This is based on the assumption that
the module name is unique across the tree. This assumption is really
fragile.

Stephen Rothwell reported a race condition caused by a module name
conflict:

  https://lkml.org/lkml/2019/5/13/991

In parallel building, two different threads could write to the same
$(MODVERDIR)/*.mod simultaneously.

Non-unique module names are the source of all kind of troubles, hence
commit 3a48a91901c5 ("kbuild: check uniqueness of module names")
introduced a new checker script.

However, it is still fragile in the build system point of view because
this race happens before scripts/modules-check.sh is invoked. If it
happens again, the modpost will emit unclear error messages.

To fix this issue completely, create *.mod with full directory path
so that two threads never attempt to write to the same file.

$(MODVERDIR) is no longer needed.

Since modules with directory paths are listed in modules.order, Kbuild
is still able to find *.mod files without additional descending.

I also killed cmd_secanalysis; scripts/mod/sumversion.c computes MD4 hash
for modules with MODULE_VERSION(). When CONFIG_DEBUG_SECTION_MISMATCH=y,
it occurs not only in the modpost stage, but also during directory
descending, where sumversion.c may parse stale *.mod files. It would emit
'No such file or directory' warning when an object consisting a module is
renamed, or when a single-obj module is turned into a multi-obj module or
vice versa.

Signed-off-by: Masahiro Yamada 
Acked-by: Nicolas Pitre