On 25.05.2020 12:00, [email protected] wrote: > From: Cixi Geng <[email protected]> > > The CONFIG_GCOV_PROFILE_ALL will compile kernel by profiling entire > kernel which will lead to kernel run slower.Use GCOV_PROFILE_PREREQS > to control part of the kernel modules to open gcov.
Maybe rephrase the commit message to make the intention more obvious: Introduce new configuration option GCOV_PROFILE_PREREQS that can be used to check whether the prerequisites for enabling gcov profiling for specific files and directories are met. > > Only add SERIAL_GCOV for an example. > > Signed-off-by: Cixi Geng <[email protected]> > --- > drivers/tty/serial/Kconfig | 7 +++++++ > drivers/tty/serial/Makefile | 1 + > kernel/gcov/Kconfig | 14 ++++++++++++++ > 3 files changed, 22 insertions(+) > > diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig > index adf9e80e7dc9..6df002370f18 100644 > --- a/drivers/tty/serial/Kconfig > +++ b/drivers/tty/serial/Kconfig > @@ -1566,3 +1566,10 @@ endmenu > > config SERIAL_MCTRL_GPIO > tristate > + > +config SERIAL_GCOV > + bool "Enable profile gcov for serial directory" > + depends on GCOV_PROFILE_PREREQS > + help > + The SERIAL_GCOV will add Gcov profiling flags when kernel compiles. > + Say 'Y' here if you want the gcov data for the serial directory, > diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile > index d056ee6cca33..17272733db95 100644 > --- a/drivers/tty/serial/Makefile > +++ b/drivers/tty/serial/Makefile > @@ -3,6 +3,7 @@ > # Makefile for the kernel serial device drivers. > # > > +GCOV_PROFILE := $(CONFIG_SERIAL_GCOV) > obj-$(CONFIG_SERIAL_CORE) += serial_core.o > > obj-$(CONFIG_SERIAL_EARLYCON) += earlycon.o > diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig > index 3941a9c48f83..ea8b514f5676 100644 > --- a/kernel/gcov/Kconfig > +++ b/kernel/gcov/Kconfig > @@ -51,6 +51,20 @@ config GCOV_PROFILE_ALL > larger and run slower. Also be sure to exclude files from profiling > which are not linked to the kernel image to prevent linker errors. > > +config GCOV_PROFILE_PREREQS > + bool "Profile Kernel subsytem" > + depends on !COMPILE_TEST > + depends on GCOV_KERNEL > + depends on !GCOV_PROFILE_ALL > + help > + This options activates profiling for the specified kernel modules. > + > + When some modules need Gcov data, enable this config, then configure > + with gcov on the corresponding modules,The directories or files of > + these modules will be added profiling flags after kernel compile. > + > + If unsure, say N. This is not quite what I had in mind. A user still needs to manually select GCOV_PROFILE, then GCOV_PROFILE_PREREQS, then SERIAL_GCOV. My though was that you could provide an automatic config option that is invisible in the configuration dialog, and that is automatically selected when all prereqs for enabling GCOV in a module directory are met. Something like the following: config GCOV_PROFILE_PREREQS bool default y if GCOV_KERNEL && !COMPILE_TEST default n There's no need to add GCOV_KERNEL_ALL here since that is about a user choice ("I want all code compiled with profiling") vs. this new symbol which is about an ability ("all prereqs for enabling profiling in specific directories are met). > + > choice > prompt "Specify GCOV format" > depends on GCOV_KERNEL > -- Peter Oberparleiter Linux on Z Development - IBM Germany
