Hi Greg: DId you mean that the GCOV_PROFILE_PREREQS should add depends on !GCOV_PROFILE_ALL ,then when GCOV_PROFILE_ALL is enabled, the config GCOV_PROFILE_PREREQS will no longer works. Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> 于2020年5月22日周五 下午4:37写道： > > On Fri, May 22, 2020 at 03:19:17PM +0800, gengcixi@xxxxxxxxx wrote: > > From: Cixi Geng <cixi.geng1@xxxxxxxxxx> > > > > 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. > > > > Only add SERIAL_GCOV for an example. > > > > Signed-off-by: Cixi Geng <cixi.geng1@xxxxxxxxxx> > > --- > > drivers/tty/serial/Kconfig | 7 +++++++ > > drivers/tty/serial/Makefile | 1 + > > kernel/gcov/Kconfig | 13 +++++++++++++ > > 3 files changed, 21 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..4d75fa158726 100644 > > --- a/kernel/gcov/Kconfig > > +++ b/kernel/gcov/Kconfig > > @@ -51,6 +51,19 @@ 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 > > + 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. > > + > > choice > > prompt "Specify GCOV format" > > depends on GCOV_KERNEL > > > I understand the goal here, but don't you need to have the main GCov > option depend on your new Kconfig option here? You have it switched > around here, so what keeps all code from being built with gcov support > at the moment? > > thanks, > > greg k-h
