diff options
| author | Ravikiran G Thirumalai <kiran@scalex86.org> | 2007-10-16 23:26:09 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-17 08:42:47 -0700 |
| commit | c4f3b63fe15b4629aa1ec163c95ab30423d0f76a (patch) | |
| tree | 432723f1c7ac2fcff0aa57377c31187140d69145 /kernel | |
| parent | a5f2ce3c6024a5bb895647b6bd88ecae5001020a (diff) | |
softlockup: add a /proc tuning parameter
Control the trigger limit for softlockup warnings. This is useful for
debugging softlockups, by lowering the softlockup_thresh to identify
possible softlockups earlier.
This patch:
1. Adds a sysctl softlockup_thresh with valid values of 1-60s
(Higher value to disable false positives)
2. Changes the softlockup printk to print the cpu softlockup time
[akpm@linux-foundation.org: Fix various warnings and add definition of "two"]
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/softlockup.c | 7 | ||||
| -rw-r--r-- | kernel/sysctl.c | 33 |
2 files changed, 31 insertions, 9 deletions
diff --git a/kernel/softlockup.c b/kernel/softlockup.c index 72c2561ff5f8..edeeef3a6a32 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -24,6 +24,7 @@ static DEFINE_PER_CPU(unsigned long, print_timestamp); static DEFINE_PER_CPU(struct task_struct *, watchdog_task); static int did_panic; +int softlockup_thresh = 10; static int softlock_panic(struct notifier_block *this, unsigned long event, void *ptr) @@ -104,13 +105,15 @@ 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_thresh)) return; per_cpu(print_timestamp, this_cpu) = touch_timestamp; spin_lock(&print_lock); - printk(KERN_ERR "BUG: soft lockup detected on CPU#%d!\n", this_cpu); + printk(KERN_ERR "BUG: soft lockup - CPU#%d stuck for %lus! [%s:%d]\n", + this_cpu, now - touch_timestamp, + current->comm, current->pid); if (regs) show_regs(regs); else diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 5e63de0f9ee2..dde3d53e8adc 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -80,6 +80,19 @@ extern int maps_protect; extern int sysctl_stat_interval; extern int audit_argv_kb; +/* Constants used for minimum and maximum */ +#ifdef CONFIG_DETECT_SOFTLOCKUP +static int one = 1; +static int sixty = 60; +#endif + +#ifdef CONFIG_MMU +static int two = 2; +#endif + +static int zero; +static int one_hundred = 100; + /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */ static int maxolduid = 65535; static int minolduid; @@ -711,6 +724,19 @@ static ctl_table kern_table[] = { .proc_handler = &proc_dointvec, }, #endif +#ifdef CONFIG_DETECT_SOFTLOCKUP + { + .ctl_name = CTL_UNNUMBERED, + .procname = "softlockup_thresh", + .data = &softlockup_thresh, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &one, + .extra2 = &sixty, + }, +#endif #ifdef CONFIG_COMPAT { .ctl_name = KERN_COMPAT_LOG, @@ -757,13 +783,6 @@ static ctl_table kern_table[] = { { .ctl_name = 0 } }; -/* Constants for minimum and maximum testing in vm_table. - We use these as one-element integer vectors. */ -static int zero; -static int two = 2; -static int one_hundred = 100; - - static ctl_table vm_table[] = { { .ctl_name = VM_OVERCOMMIT_MEMORY, |