[PATCH] recipes-kernel: disable more debugs that influence latency performance

[PATCH] recipes-kernel: disable more debugs that influence latency performance

[Hongzhan Chen]

For dovetail-based xenomai, max lat may drop from 203.800 us
to 9.807 us in 10 hours stressed latency test on Maxtang 8565U board
with lava test.

diff --git a/recipes-kernel/linux/files/common_nodbg.cfg b/recipes-kernel/linux/files/common_nodbg.cfg
index d7d87c5..29b3522 100644
--- a/recipes-kernel/linux/files/common_nodbg.cfg
+++ b/recipes-kernel/linux/files/common_nodbg.cfg
@@ -1,2 +1,9 @@
 # CONFIG_IPIPE_DEBUG is not set
 # CONFIG_XENO_OPT_DEBUG is not set
+# CONFIG_PROVE_LOCKING is not set
+# CONFIG_DEBUG_RT_MUTEXES is not set
+# CONFIG_DEBUG_SPINLOCK is not set
+# CONFIG_DEBUG_MUTEXES is not set
+# CONFIG_DEBUG_WW_MUTEX_SLOWPATH is not set
+# CONFIG_DEBUG_RWSEMS is not set
+# CONFIG_DEBUG_LOCK_ALLOC is not set
-- 
2.17.1

Re: [PATCH] recipes-kernel: disable more debugs that influence latency performance

[Philippe Gerum]

Hongzhan Chen via Xenomai <xenomai@xenomai.org> writes:

> For dovetail-based xenomai, max lat may drop from 203.800 us
> to 9.807 us in 10 hours stressed latency test on Maxtang 8565U board
> with lava test.
>
> diff --git a/recipes-kernel/linux/files/common_nodbg.cfg b/recipes-kernel/linux/files/common_nodbg.cfg
> index d7d87c5..29b3522 100644
> --- a/recipes-kernel/linux/files/common_nodbg.cfg
> +++ b/recipes-kernel/linux/files/common_nodbg.cfg
> @@ -1,2 +1,9 @@
>  # CONFIG_IPIPE_DEBUG is not set
>  # CONFIG_XENO_OPT_DEBUG is not set
> +# CONFIG_PROVE_LOCKING is not set
> +# CONFIG_DEBUG_RT_MUTEXES is not set
> +# CONFIG_DEBUG_SPINLOCK is not set
> +# CONFIG_DEBUG_MUTEXES is not set
> +# CONFIG_DEBUG_WW_MUTEX_SLOWPATH is not set
> +# CONFIG_DEBUG_RWSEMS is not set
> +# CONFIG_DEBUG_LOCK_ALLOC is not set

Maybe it's time to backport the evl-check utility [1] from xenomai4 to
xenomai3, this is a very simple kconfig checker which helps in detecting
problematic settings. One just feeds it with a set of constraints like
[2] in order to perform such detection. FWIW, this command is documented
here.

[1] https://source.denx.de/Xenomai/xenomai4/libevl/-/blob/master/utils/evl-check.c
[2]
https://source.denx.de/Xenomai/xenomai4/libevl/-/blob/master/utils/kconf-checklist.evl
[3] https://evlproject.org/core/commands/#evl-check-command

-- 
Philippe.

Re: [PATCH] recipes-kernel: disable more debugs that influence latency performance

[Jan Kiszka]

On 18.09.21 03:08, Hongzhan Chen via Xenomai wrote:
> For dovetail-based xenomai, max lat may drop from 203.800 us
> to 9.807 us in 10 hours stressed latency test on Maxtang 8565U board
> with lava test.
> 

Signed-off missing. And please tag such patches with
"[xenomai-images][PATCH]...".

> diff --git a/recipes-kernel/linux/files/common_nodbg.cfg b/recipes-kernel/linux/files/common_nodbg.cfg
> index d7d87c5..29b3522 100644
> --- a/recipes-kernel/linux/files/common_nodbg.cfg
> +++ b/recipes-kernel/linux/files/common_nodbg.cfg
> @@ -1,2 +1,9 @@
>  # CONFIG_IPIPE_DEBUG is not set
>  # CONFIG_XENO_OPT_DEBUG is not set
> +# CONFIG_PROVE_LOCKING is not set
> +# CONFIG_DEBUG_RT_MUTEXES is not set
> +# CONFIG_DEBUG_SPINLOCK is not set
> +# CONFIG_DEBUG_MUTEXES is not set
> +# CONFIG_DEBUG_WW_MUTEX_SLOWPATH is not set
> +# CONFIG_DEBUG_RWSEMS is not set
> +# CONFIG_DEBUG_LOCK_ALLOC is not set
> 

Jan

-- 
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux