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| author |   Laurent Dufour <ldufour@linux.ibm.com> | 2022-07-13 17:47:28 +0200 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2022-07-27 21:36:02 +1000 |
| commit | f5e74e836097d1004077390717d4bd95d4a2c27a (patch) | |
| tree | dff98d181edd6257d55b7ab6203e87036996b4db /arch/powerpc/kernel/watchdog.c | |
| parent | watchdog: export lockup_detector_reconfigure (diff) | |
| download | linux-dev-f5e74e836097d1004077390717d4bd95d4a2c27a.tar.xz linux-dev-f5e74e836097d1004077390717d4bd95d4a2c27a.zip | |
powerpc/watchdog: introduce a NMI watchdog's factor
Introduce a factor which would apply to the NMI watchdog timeout.
This factor is a percentage added to the watchdog_tresh value. The value is
set under the watchdog_mutex protection and lockup_detector_reconfigure()
is called to recompute wd_panic_timeout_tb.
Once the factor is set, it remains until it is set back to 0, which means
no impact.
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220713154729.80789-4-ldufour@linux.ibm.com
Diffstat (limited to 'arch/powerpc/kernel/watchdog.c')
| -rw-r--r-- | arch/powerpc/kernel/watchdog.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c index dd882d00845d..dbcc4a793f0b 100644 --- a/arch/powerpc/kernel/watchdog.c +++ b/arch/powerpc/kernel/watchdog.c @@ -91,6 +91,10 @@ static cpumask_t wd_smp_cpus_pending; static cpumask_t wd_smp_cpus_stuck; static u64 wd_smp_last_reset_tb; +#ifdef CONFIG_PPC_PSERIES +static u64 wd_timeout_pct; +#endif + /* * Try to take the exclusive watchdog action / NMI IPI / printing lock. * wd_smp_lock must be held. If this fails, we should return and wait @@ -527,7 +531,13 @@ static int stop_watchdog_on_cpu(unsigned int cpu) static void watchdog_calc_timeouts(void) { - wd_panic_timeout_tb = watchdog_thresh * ppc_tb_freq; + u64 threshold = watchdog_thresh; + +#ifdef CONFIG_PPC_PSERIES + threshold += (READ_ONCE(wd_timeout_pct) * threshold) / 100; +#endif + + wd_panic_timeout_tb = threshold * ppc_tb_freq; /* Have the SMP detector trigger a bit later */ wd_smp_panic_timeout_tb = wd_panic_timeout_tb * 3 / 2; @@ -570,3 +580,12 @@ int __init watchdog_nmi_probe(void) } return 0; } + +#ifdef CONFIG_PPC_PSERIES +void watchdog_nmi_set_timeout_pct(u64 pct) +{ + pr_info("Set the NMI watchdog timeout factor to %llu%%\n", pct); + WRITE_ONCE(wd_timeout_pct, pct); + lockup_detector_reconfigure(); +} +#endif |