menu "GCOV-based kernel profiling"
config GCOV_KERNEL
bool "Enable gcov-based kernel profiling"
depends on DEBUG_FS
select CONSTRUCTORS if !UML
default n
---help---
This option enables gcov-based code profiling (e.g. for code coverage
measurements).
If unsure, say N.
Additionally specify CONFIG_GCOV_PROFILE_ALL=y to get profiling data
for the entire kernel. To enable profiling for specific files or
directories, add a line similar to the following to the respective
Makefile:
For a single file (e.g. main.o):
GCOV_PROFILE_main.o := y
For all files in one directory:
GCOV_PROFILE := y
To exclude files from being profiled even when CONFIG_GCOV_PROFILE_ALL
is specified, use:
GCOV_PROFILE_main.o := n
and:
GCOV_PROFILE := n
Note that the debugfs filesystem has to be mounted to access
profiling data.
config ARCH_HAS_GCOV_PROFILE_ALL
def_bool n
config GCOV_PROFILE_ALL
bool "Profile entire Kernel"
depends on !COMPILE_TEST
depends on GCOV_KERNEL
depends on ARCH_HAS_GCOV_PROFILE_ALL
default n
---help---
This options activates profiling for the entire kernel.
If unsure, say N.
Note that a kernel compiled with profiling flags will be significantly
larger and run slower. Also be sure to exclude files from profiling
which are not linked to the kernel image to prevent linker errors.
choice
prompt "Specify GCOV format"
depends on GCOV_KERNEL
default GCOV_FORMAT_AUTODETECT
---help---
The gcov format is usually determined by the GCC version, but there are
exceptions where format changes are integrated in lower-version GCCs.
In such a case use this option to adjust the format used in the kernel
accordingly.
If unsure, choose "Autodetect".
config GCOV_FORMAT_AUTODETECT
bool "Autodetect"
---help---
Select this option to use the format that corresponds to your GCC
version.
config GCOV_FORMAT_3_4
bool "GCC 3.4 format"
---help---
Select this option to use the format defined by GCC 3.4.
config GCOV_FORMAT_4_7
bool "GCC 4.7 format"
---help---
Select this option to use the format defined by GCC 4.7.
endchoice
endmenu
803499bd623b737070038af94d0b8a3c7'>commitdiff|
|
perf/x86/intel/rapl: Make package handling more robust
The package management code in RAPL relies on package mapping being
available before a CPU is started. This changed with:
9d85eb9119f4 ("x86/smpboot: Make logical package management more robust")
because the ACPI/BIOS information turned out to be unreliable, but that
left RAPL in broken state. This was not noticed because on a regular boot
all CPUs are online before RAPL is initialized.
A possible fix would be to reintroduce the mess which allocates a package
data structure in CPU prepare and when it turns out to already exist in
starting throw it away later in the CPU online callback. But that's a
horrible hack and not required at all because RAPL becomes functional for
perf only in the CPU online callback. That's correct because user space is
not yet informed about the CPU being onlined, so nothing caan rely on RAPL
being available on that particular CPU.
Move the allocation to the CPU online callback and simplify the hotplug
handling. At this point the package mapping is established and correct.
This also adds a missing check for available package data in the
event_init() function.
Reported-by: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 9d85eb9119f4 ("x86/smpboot: Make logical package management more robust")
Link: http://lkml.kernel.org/r/20170131230141.212593966@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>