diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-02-23 09:28:37 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-02-23 09:28:37 -0800 |
| commit | 525445efacdfeed71329ce8bc5f558859a894b8b (patch) | |
| tree | 6cdf76560eae119b561bade1846dffa3b182da21 /lib | |
| parent | 192a5e0a19712a079f456954c203ce9dd2b889fa (diff) | |
| parent | 344da544f177f919cf6919e5abcd388f27aa53db (diff) | |
Merge tag 'nmi.2023.02.14a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull x86 NMI diagnostics from Paul McKenney:
"Add diagnostics to the x86 NMI handler to help detect NMI-handler bugs
on the one hand and failing hardware on the other"
* tag 'nmi.2023.02.14a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
x86/nmi: Print reasons why backtrace NMIs are ignored
x86/nmi: Accumulate NMI-progress evidence in exc_nmi()
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 11 | ||||
| -rw-r--r-- | lib/nmi_backtrace.c | 2 |
2 files changed, 13 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index cecae75d7519..5a69b3805b1c 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1562,6 +1562,17 @@ config TRACE_IRQFLAGS_NMI depends on TRACE_IRQFLAGS depends on TRACE_IRQFLAGS_NMI_SUPPORT +config NMI_CHECK_CPU + bool "Debugging for CPUs failing to respond to backtrace requests" + depends on DEBUG_KERNEL + depends on X86 + default n + help + Enables debug prints when a CPU fails to respond to a given + backtrace NMI. These prints provide some reasons why a CPU + might legitimately be failing to respond, for example, if it + is offline of if ignore_nmis is set. + config DEBUG_IRQFLAGS bool "Debug IRQ flag manipulation" help diff --git a/lib/nmi_backtrace.c b/lib/nmi_backtrace.c index d01aec6ae15c..5274bbb026d7 100644 --- a/lib/nmi_backtrace.c +++ b/lib/nmi_backtrace.c @@ -64,6 +64,7 @@ void nmi_trigger_cpumask_backtrace(const cpumask_t *mask, if (!cpumask_empty(to_cpumask(backtrace_mask))) { pr_info("Sending NMI from CPU %d to CPUs %*pbl:\n", this_cpu, nr_cpumask_bits, to_cpumask(backtrace_mask)); + nmi_backtrace_stall_snap(to_cpumask(backtrace_mask)); raise(to_cpumask(backtrace_mask)); } @@ -74,6 +75,7 @@ void nmi_trigger_cpumask_backtrace(const cpumask_t *mask, mdelay(1); touch_softlockup_watchdog(); } + nmi_backtrace_stall_check(to_cpumask(backtrace_mask)); /* * Force flush any remote buffers that might be stuck in IRQ context |