Messages in this thread | | | Date | Wed, 23 Apr 2008 14:55:17 -0700 | From | Randy Dunlap <> | Subject | Re: [PATCH] disable softlockup detection at boottime |
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On Wed, 23 Apr 2008 15:16:13 -0500 Dimitri Sivanich wrote:
> This patch allows softlockup detection to be disabled by specifying > a boottime parameter.
Seems to be missing (a) justification/why and (b) entry in Documentation/kernel-parameters.txt
> Signed-off-by: Dimitri Sivanich <sivanich@sgi.com> > > Index: linux/kernel/softlockup.c > =================================================================== > --- linux.orig/kernel/softlockup.c 2008-04-23 13:50:06.000000000 -0500 > +++ linux/kernel/softlockup.c 2008-04-23 14:39:36.267398531 -0500 > @@ -24,6 +24,7 @@ static DEFINE_PER_CPU(unsigned long, tou > static DEFINE_PER_CPU(unsigned long, print_timestamp); > static DEFINE_PER_CPU(struct task_struct *, watchdog_task); > > +static int __read_mostly softlockup_off; > static int __read_mostly did_panic; > unsigned long __read_mostly softlockup_thresh = 60; > > @@ -53,7 +54,8 @@ void touch_softlockup_watchdog(void) > { > int this_cpu = raw_smp_processor_id(); > > - __raw_get_cpu_var(touch_timestamp) = get_timestamp(this_cpu); > + if (!softlockup_off) > + __raw_get_cpu_var(touch_timestamp) = get_timestamp(this_cpu); > } > EXPORT_SYMBOL(touch_softlockup_watchdog); > > @@ -61,6 +63,9 @@ void touch_all_softlockup_watchdogs(void > { > int cpu; > > + if (softlockup_off) > + return; > + > /* Cause each CPU to re-update its timestamp rather than complain */ > for_each_online_cpu(cpu) > per_cpu(touch_timestamp, cpu) = 0; > @@ -79,6 +84,9 @@ void softlockup_tick(void) > struct pt_regs *regs = get_irq_regs(); > unsigned long now; > > + if (softlockup_off) > + return; > + > if (touch_timestamp == 0) { > touch_softlockup_watchdog(); > return; > @@ -306,9 +314,19 @@ __init void spawn_softlockup_task(void) > void *cpu = (void *)(long)smp_processor_id(); > int err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu); > > + if (softlockup_off) > + return; > + > BUG_ON(err == NOTIFY_BAD); > cpu_callback(&cpu_nfb, CPU_ONLINE, cpu); > register_cpu_notifier(&cpu_nfb); > > atomic_notifier_chain_register(&panic_notifier_list, &panic_block); > } > + > +static int __init disable_softlockup_detection(char *str) > +{ > + softlockup_off = 1; > + return 1; > +} > +__setup("nosoftlockup", disable_softlockup_detection); > --
--- ~Randy
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