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| author | Paul E. McKenney <paulmck@kernel.org> | 2020-09-04 20:54:52 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-09-04 20:54:52 +0200 |
| commit | 6fe208f63a79f4f726f3be2b78ea3dd40487b657 (patch) | |
| tree | 1b826243b70f09e101081d5ea6dd59aa37fe25a9 /lib | |
| parent | Merge branch 'strictgp.2020.08.24a' into HEAD (diff) | |
| parent | smp: Make symbol 'csd_bug_count' static (diff) | |
| download | linux-6fe208f63a79f4f726f3be2b78ea3dd40487b657.tar.xz linux-6fe208f63a79f4f726f3be2b78ea3dd40487b657.zip | |
Merge branch 'csd.2020.09.04a' into HEAD
csd.2020.09.04a: CPU smp_call_function() torture tests.
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 11 | ||||
| -rw-r--r-- | lib/nmi_backtrace.c | 6 |
2 files changed, 16 insertions, 1 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 0c3a6c752ede..4ac6f61b9475 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1377,6 +1377,17 @@ config SCF_TORTURE_TEST module may be built after the fact on the running kernel to be tested, if desired. +config CSD_LOCK_WAIT_DEBUG + bool "Debugging for csd_lock_wait(), called from smp_call_function*()" + depends on DEBUG_KERNEL + depends on 64BIT + default n + help + This option enables debug prints when CPUs are slow to respond + to the smp_call_function*() IPI wrappers. These debug prints + include the IPI handler function currently executing (if any) + and relevant stack traces. + endmenu # lock debugging config TRACE_IRQFLAGS diff --git a/lib/nmi_backtrace.c b/lib/nmi_backtrace.c index 15ca78e1c7d4..8abe1870dba4 100644 --- a/lib/nmi_backtrace.c +++ b/lib/nmi_backtrace.c @@ -85,12 +85,16 @@ void nmi_trigger_cpumask_backtrace(const cpumask_t *mask, put_cpu(); } +// Dump stacks even for idle CPUs. +static bool backtrace_idle; +module_param(backtrace_idle, bool, 0644); + bool nmi_cpu_backtrace(struct pt_regs *regs) { int cpu = smp_processor_id(); if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) { - if (regs && cpu_in_idle(instruction_pointer(regs))) { + if (!READ_ONCE(backtrace_idle) && regs && cpu_in_idle(instruction_pointer(regs))) { pr_warn("NMI backtrace for cpu %d skipped: idling at %pS\n", cpu, (void *)instruction_pointer(regs)); } else { |