Messages in this thread Patch in this message | | | From | "Paul E. McKenney" <> | Subject | [PATCH CSDlock 4/4] kernel/smp: Make csdlock_debug= resettable | Date | Mon, 20 Mar 2023 17:55:16 -0700 |
| |
It is currently possible to set the csdlock_debug_enabled static branch, but not to reset it. This is an issue when several different entities supply kernel boot parameters and also for kernels built with CONFIG_CSD_LOCK_WAIT_DEBUG_DEFAULT=y.
Therefore, make the csdlock_debug=0 kernel boot parameter turn off debugging. Last one wins!
Reported-by: Jes Sorensen <Jes.Sorensen@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> --- Documentation/admin-guide/kernel-parameters.txt | 13 +++++++------ kernel/smp.c | 11 ++++++++--- 2 files changed, 15 insertions(+), 9 deletions(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index b15198a85acb..5f2ec4b0f927 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -889,12 +889,13 @@ cs89x0_media= [HW,NET] Format: { rj45 | aui | bnc } - csdlock_debug= [KNL] Enable debug add-ons of cross-CPU function call - 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. The default value of - this option depends on the CSD_LOCK_WAIT_DEBUG_DEFAULT + csdlock_debug= [KNL] Enable or disable debug add-ons of cross-CPU + function call 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. The default value of this + option depends on the CSD_LOCK_WAIT_DEBUG_DEFAULT Kconfig option. dasd= [HW,NET] diff --git a/kernel/smp.c b/kernel/smp.c index 7a85bcddd9dc..298ba7570621 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -116,11 +116,16 @@ static DEFINE_STATIC_KEY_MAYBE(CONFIG_CSD_LOCK_WAIT_DEBUG_DEFAULT, csdlock_debug */ static int __init csdlock_debug(char *str) { + int ret; unsigned int val = 0; - get_option(&str, &val); - if (val) - static_branch_enable(&csdlock_debug_enabled); + ret = get_option(&str, &val); + if (ret) { + if (val) + static_branch_enable(&csdlock_debug_enabled); + else + static_branch_disable(&csdlock_debug_enabled); + } return 1; } -- 2.40.0.rc2
| |