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    SubjectRe: [PATCH 3/5] gcov: disable for COMPILE_TEST
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    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 <arnd@arndb.de>

    Agreed that COMPILE_TEST + GCOV_PROFILE_ALL is a very exotic combination
    with little added use.

    Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>

    > ---
    > 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

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