Re: [PATCH 0/2] riscv: defconfigs: enable debugging options

[Palmer Dabbelt]

On Fri, 22 Nov 2019 14:56:57 PST (-0800), Paul Walmsley wrote:
> Enable more debugging options in the defconfig.  Debugfs is generally
> useful for everyone; the other options are intended to make it easier
> for developers and testers to catch problems earlier.
>
>
> - Paul
>
> Paul Walmsley (2):
>   riscv: defconfigs: enable debugfs
>   riscv: defconfigs: enable more debugging options
>
>  arch/riscv/configs/defconfig      | 24 ++++++++++++++++++++++++
>  arch/riscv/configs/rv32_defconfig | 24 ++++++++++++++++++++++++
>  2 files changed, 48 insertions(+)
>
>
> Kernel object size difference:
>    text	   data	    bss	    dec	    hex	filename
> 6665154	2132584	 312608	9110346	 8b034a	vmlinux.rv64.orig
> 6779347	2299448	 313600	9392395	 8f510b	vmlinux.rv64.patched
> 6445414	1797616	 255248	8498278	 81ac66	vmlinux.rv32.orig
> 6552029	1921996	 257448	8731473	 853b51	vmlinux.rv32.patched

Does it make sense to turn on some CONFIG_*_SELFTEST entries as well?  I know
I've found RISC-V bugs with ATOMIC64_SELFTEST before, but they do take a while
to run.  I just turned on 

    diff --git a/arch/riscv/configs/defconfig b/arch/riscv/configs/defconfig
    index 420a0dbef386..90001c3746cd 100644
    --- a/arch/riscv/configs/defconfig
    +++ b/arch/riscv/configs/defconfig
    @@ -100,4 +100,18 @@ CONFIG_9P_FS=y
     CONFIG_CRYPTO_USER_API_HASH=y
     CONFIG_CRYPTO_DEV_VIRTIO=y
     CONFIG_PRINTK_TIME=y
    +CONFIG_DEBUG_RT_MUTEXES=y
    +CONFIG_DEBUG_SPINLOCK=y
    +CONFIG_DEBUG_MUTEXES=y
    +CONFIG_DEBUG_RWSEMS=y
    +CONFIG_DEBUG_ATOMIC_SLEEP=y
    +CONFIG_DEBUG_LOCKING_API_SELFTESTS=y
    +CONFIG_LOCK_TORTURE_TEST=y
    +CONFIG_WW_MUTEX_SELFTEST=y
    +CONFIG_RCU_PERF_TEST=y
    +CONFIG_RCU_TORTURE_TEST=y
     # CONFIG_RCU_TRACE is not set
    +CONFIG_PERCPU_TEST=m
    +CONFIG_ATOMIC64_SELFTEST=y
    +CONFIG_TEST_LKM=m
    +CONFIG_TEST_USER_COPY=m

as an experiment and OE looks like it's still functional, but it looks like the
lock torture stuff keeps running and the RCU torture can't run at the same
time.

Either way, this looks good to me!