Rebuild and Install Module i915 for GPU Analysis on CentOS*
Rebuild and Install Module i915 for GPU Analysis on CentOS*
To collect i915 ftrace events required to analyze the
GPU utilization, your Linux kernel should be properly configured. If the Intel® VTune™ Profiler cannot start an analysis and provides an error message:
Collection of GPU usage events cannot be enabled. i915 ftrace events are not available
. You need to rebuild and install the re-configured i915 module. For example, for kernel 4.14 and higher, these settings should be enabled:
CONFIG_EXPERT=y
and
CONFIG_DRM_I915_LOW_LEVEL_TRACEPOINTS=y
.
If you update the kernel often, make sure to
build the special kernel for GPU analysis.
On CentOS* systems, if you update the kernel rarely, you can configure and rebuild only module i915 as follows:
Installing the kernel requires root permissions.
- Install build dependencies:sudo yum install flex bison elfutils-libelf-devel
- Create a folder for kernel source:mkdir -p /tmp/kernel cd !$
- Get your kernel version:uname -rThis is an example of the command output:4.18.0-80.11.2.el8_0.x86_64
- Get source code for the kernel:wget http://vault.centos.org/8.0.1905/BaseOS/Source/SPackages/kernel-4.18.0-80.11.2.el8_0.src.rpmrpm --define "_topdir /tmp/kernel/rpmbuild" -i kernel-4.18.0-80.11.2.el8_0.src.rpmtar -xf ./rpmbuild/SOURCES/linux-4.18.0-80.11.2.el8_0.tar.xz
- Change the current directory:cd linux-*
- Configure the kernel modules:cp /usr/src/kernels/$(uname -r)/.config ./cp /usr/src/kernels/$(uname -r)/Module.symvers ./
- Update the version in Makefile in the current directory.The version value must be the same as in theuname -rcommand output. For example, ifuname -rprints4.18.0-80.11.2.el8_0.x86_64, the values in the Makefile should be:VERSION = 4PATCHLEVEL = 18SUBLEVEL = 0EXTRAVERSION = -80.11.2.el8_0.x86_64Update the file, if required, and save it.
- Make sure the kernel version is set correctly in the Makefile:make kernelversionThe command output for the example above is the following:4.18.0-80.11.2.el8_0.x86_64
- In the new.configfile, make sure the following settings are enabled:CONFIG_EXPERT=yCONFIG_FTRACE=yCONFIG_DEBUG_FS=yCONFIG_DRM_I915_LOW_LEVEL_TRACEPOINTS=yUpdate the file, if required, and save it.
- Create a fullconfigfile for the kernel:make olddefconfig
- Build module i915:make -j$(getconf _NPROCESSORS_ONLN) modules_preparemake -j$(getconf _NPROCESSORS_ONLN) M=./drivers/gpu/drm/i915 modulesIf you get the following error:LD [M] drivers/gpu/drm/i915/i915.o ld: no input filesyou need to replace the following lines inscripts/Makefile.build:link_multi_deps = \ $(filter $(addprefix $(obj)/, \ $($(subst $(obj)/,,$(@:.o=-objs)) \ $($(subst $(obj)/,,$(@:.o=-y))) \ $($(subst $(obj)/,,$(@:.o=-m)))),$^)with the line:link_multi_deps = $(filter %.o,$^)See the patch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=69ea912fda74a673d330d23595385e5b73e3a2b9 for more information.
- Install the new module:sudo make M=./drivers/gpu/drm/i915 modules_install
- Make sure the folder with the new driver is present in/etc/depmod.d/*files, or just add it:echo "search extradrivers" | sudo tee /etc/depmod.d/00-extra.conf
- Updateinitramfs:sudo depmod sudo dracut --force
- Reboot the machine:sudo reboot
- Make sure the new driver is loaded:modinfo i915 | grep filenameThe command output should be the following:filename: /lib/modules/4.18.0-80.11.2.el8_0.x86_64/extradrivers/gpu/drm/i915/i915.ko
To roll back the changes and load the original module i915:
- Remove the folder with the new driver from/etc/depmod.d/*files:sudo rm /etc/depmod.d/00-extra.conf
- Updateinitramfs:sudo depmod sudo update-initramfs -u
- Reboot the machine:sudo reboot