Kernel warns of softlockups if the softlockup thread is not able to run on a CPU for 10s. It is useful to lower the softlockup warning threshold in testing environments to catch potential lockups early. Following patch adds a kernel parameter 'softlockup_lim' to control the softlockup threshold.
Thanks, Kiran Control the trigger limit for softlockup warnings. This is useful for debugging softlockups, by lowering the softlockup_lim to identify possible softlockups earlier. Signed-off-by: Ravikiran Thirumalai <[EMAIL PROTECTED]> Signed-off-by: Shai Fultheim <[EMAIL PROTECTED]> Index: linux-2.6.22/Documentation/kernel-parameters.txt =================================================================== --- linux-2.6.22.orig/Documentation/kernel-parameters.txt 2007-07-08 16:32:17.000000000 -0700 +++ linux-2.6.22/Documentation/kernel-parameters.txt 2007-07-16 14:07:34.907116001 -0700 @@ -1781,6 +1781,10 @@ and is between 256 and 4096 characters. snd-ymfpci= [HW,ALSA] + softlockup_lim= + [KNL] Soft lock up tolerance limit in seconds + { 1 - 10 } + sonycd535= [HW,CD] Format: <io>[,<irq>] Index: linux-2.6.22/kernel/softlockup.c =================================================================== --- linux-2.6.22.orig/kernel/softlockup.c 2007-07-08 16:32:17.000000000 -0700 +++ linux-2.6.22/kernel/softlockup.c 2007-07-11 12:50:05.280460591 -0700 @@ -21,6 +21,7 @@ static DEFINE_PER_CPU(unsigned long, pri static DEFINE_PER_CPU(struct task_struct *, watchdog_task); static int did_panic = 0; +static int softlockup_lim = 10; static int softlock_panic(struct notifier_block *this, unsigned long event, void *ptr) @@ -34,6 +35,20 @@ static struct notifier_block panic_block .notifier_call = softlock_panic, }; +static int __init softlockup_lim_setup(char *str) +{ + int lim = simple_strtol(str, NULL, 0); + if(lim > 0 && lim <= 10) { + softlockup_lim = lim; + } else { + printk("%s: Invalid softlockup_lim parameter. ", __func__); + printk("Using defaults.\n"); + } + return 1; +} + +__setup("softlockup_lim=", softlockup_lim_setup); + /* * Returns seconds, approximately. We don't need nanosecond * resolution, and we don't need to waste time with a big divide when @@ -97,7 +112,7 @@ void softlockup_tick(void) wake_up_process(per_cpu(watchdog_task, this_cpu)); /* Warn about unreasonable 10+ seconds delays: */ - if (now > (touch_timestamp + 10)) { + if (now > (touch_timestamp + softlockup_lim)) { per_cpu(print_timestamp, this_cpu) = touch_timestamp; spin_lock(&print_lock); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/