3.18-stable review patch. If anyone has any objections, please let me know.
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From: Arnd Bergmann arnd@arndb.de
commit cc622420798c4bcf093785d872525087a7798db9 upstream.
Enabling gcov is counterproductive to compile testing: it significantly increases the kernel image size, compile time, and it produces lots of false positive "may be used uninitialized" warnings as the result of missed optimizations.
This is in line with how UBSAN_SANITIZE_ALL and PROFILE_ALL_BRANCHES work, both of which have similar problems.
With an ARM allmodconfig kernel, I see the build time drop from 283 minutes CPU time to 225 minutes, and the vmlinux size drops from 43MB to 26MB.
Signed-off-by: Arnd Bergmann arnd@arndb.de Acked-by: Peter Oberparleiter oberpar@linux.vnet.ibm.com Signed-off-by: Michal Marek mmarek@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/gcov/Kconfig | 1 + 1 file changed, 1 insertion(+)
--- a/kernel/gcov/Kconfig +++ b/kernel/gcov/Kconfig @@ -34,6 +34,7 @@ config GCOV_KERNEL
config GCOV_PROFILE_ALL bool "Profile entire Kernel" + depends on !COMPILE_TEST depends on GCOV_KERNEL depends on SUPERH || S390 || X86 || PPC || MICROBLAZE || ARM || ARM64 default n