kernelci.build: Add a kselftest-slim fragment

The kselftest fragment is a constant source of problems booting
boards since it ends up being very much larger than standard
configurations which cause lots of problems for u-boot boards,
limiting our ability to run the selftests and creating constant
overhead.  This mainly comes from the cpufreq and LKDTM
fragments, they turn on some options which instrument the entire
kernel which adds overhead everywhere.

Add a new special Kconfig fragment type kselftest-slim which
merges all fragments other than those two.  For x86_64 defconfig
this produces a substantial improvement in image size,
bloat-o-meter reports:

  Total: Before=38073475, After=24629302, chg -35.31%

for kselftest and kselftest-slim.  If other fragments start
causing similar issues we can add them to the list filtered out
by kselftest-slim.

Signed-off-by: Mark Brown <[email protected]>

Author: broonie

kernelci/build.py

@@ -241,11 +241,12 @@ def make_tarball(kdir, tarball_name):
     os.chdir(cwd)
 
 
-def generate_kselftest_fragment(frag, kdir):
+def generate_kselftest_fragment(frag, kdir, skip=[]):
     """Create a config fragment file for kselftest
 
     *frag* is a Fragment object
     *kdir* is the path to a kernel source directory
+    *skip* is a list of kselftests to skip
     """
     shell_cmd(r"""
 set -e
@@ -259,6 +260,8 @@ def generate_kselftest_fragment(frag, kdir):
 """.format(kdir=kdir, frag_path=frag.path))
     with open(os.path.join(kdir, frag.path), 'a') as f:
         for kernel_config in frag.configs:
+            if kernel_config in enumerate(skip):
+                continue
             f.write(kernel_config + '\n')
 
 
@@ -273,6 +276,12 @@ def generate_config_fragment(frag, kdir):
             f.write(kernel_config + '\n')
 
 
+slim_skip_frags = [
+    "tools/testing/selftests/lkdtm/config",
+    "tools/testing/selftests/cpufreq/config"
+]
+
+
 def generate_fragments(config, kdir):
     """Generate all the config fragments for a given build configuration
 
@@ -288,6 +297,8 @@ def generate_fragments(config, kdir):
         print(frag.path)
         if frag.name == 'kselftest':
             generate_kselftest_fragment(frag, kdir)
+        elif frag.name == 'kselftest-slim':
+            generate_kselftest_fragment(frag, kdir, skip=slim_skip_frags)
         elif frag.configs:
             generate_config_fragment(frag, kdir)