From mboxrd@z Thu Jan 1 00:00:00 1970 From: oberpar@linux.vnet.ibm.com (Peter Oberparleiter) Date: Mon, 15 Feb 2016 15:23:19 +0100 Subject: [PATCH 3/5] gcov: disable for COMPILE_TEST In-Reply-To: <1455293187-179811-4-git-send-email-arnd@arndb.de> References: <1455293187-179811-1-git-send-email-arnd@arndb.de> <1455293187-179811-4-git-send-email-arnd@arndb.de> Message-ID: <56C1DF57.50601@linux.vnet.ibm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 12.02.2016 17:06, Arnd Bergmann wrote: > 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 Agreed that COMPILE_TEST + GCOV_PROFILE_ALL is a very exotic combination with little added use. Acked-by: Peter Oberparleiter > --- > kernel/gcov/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig > index c92e44855ddd..1276aabaab55 100644 > --- a/kernel/gcov/Kconfig > +++ b/kernel/gcov/Kconfig > @@ -37,6 +37,7 @@ config ARCH_HAS_GCOV_PROFILE_ALL > > config GCOV_PROFILE_ALL > bool "Profile entire Kernel" > + depends on !COMPILE_TEST > depends on GCOV_KERNEL > depends on ARCH_HAS_GCOV_PROFILE_ALL > default n > -- Peter Oberparleiter Linux on z Systems Development - IBM Germany