The following commit has been merged into the smp/core branch of tip: Commit-ID: c52198601695851622f361d3f16456e9fc857629 Gitweb: https://git.kernel.org/tip/c52198601695851622f361d3f16456e9fc857629 Author: Paul E. McKenney <paulmck@xxxxxxxxxx> AuthorDate: Mon, 20 Mar 2023 17:55:13 -07:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Fri, 24 Mar 2023 11:01:25 +01:00 locking/csd_lock: Add Kconfig option for csd_debug default The csd_debug kernel parameter works well, but is inconvenient in cases where it is more closely associated with boot loaders or automation than with a particular kernel version or release. Thererfore, provide a new CSD_LOCK_WAIT_DEBUG_DEFAULT Kconfig option that defaults csd_debug to 1 when selected and 0 otherwise, with this latter being the default. Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Acked-by: Juergen Gross <jgross@xxxxxxxx> Link: https://lore.kernel.org/r/20230321005516.50558-1-paulmck@xxxxxxxxxx --- Documentation/admin-guide/kernel-parameters.txt | 6 ++++-- kernel/smp.c | 2 +- lib/Kconfig.debug | 9 +++++++++ 3 files changed, 14 insertions(+), 3 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 6221a1d..ce70777 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -893,8 +893,10 @@ handling. When switched on, additional debug data is printed to the console in case a hanging CPU is detected, and that CPU is pinged again in order to try - to resolve the hang situation. - 0: disable csdlock debugging (default) + to resolve the hang situation. The default value of + this option depends on the CSD_LOCK_WAIT_DEBUG_DEFAULT + Kconfig option. + 0: disable csdlock debugging 1: enable basic csdlock debugging (minor impact) ext: enable extended csdlock debugging (more impact, but more data) diff --git a/kernel/smp.c b/kernel/smp.c index 06a4139..e2d558f 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -158,7 +158,7 @@ void __init call_function_init(void) #ifdef CONFIG_CSD_LOCK_WAIT_DEBUG -static DEFINE_STATIC_KEY_FALSE(csdlock_debug_enabled); +static DEFINE_STATIC_KEY_MAYBE(CONFIG_CSD_LOCK_WAIT_DEBUG_DEFAULT, csdlock_debug_enabled); static DEFINE_STATIC_KEY_FALSE(csdlock_debug_extended); static int __init csdlock_debug(char *str) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c8b379e..e1b160a 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1480,6 +1480,15 @@ config CSD_LOCK_WAIT_DEBUG include the IPI handler function currently executing (if any) and relevant stack traces. +config CSD_LOCK_WAIT_DEBUG_DEFAULT + bool "Default csd_lock_wait() debugging on at boot time" + depends on CSD_LOCK_WAIT_DEBUG + depends on 64BIT + default n + help + This option causes the csdlock_debug= kernel boot parameter to + default to 1 (basic debugging) instead of 0 (no debugging). + endmenu # lock debugging config TRACE_IRQFLAGS
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