From 9c44bc03fff44ff04237a7d92e35304a0e50c331 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 12 May 2008 21:21:04 +0200 Subject: softlockup: allow panic on lockup allow users to configure the softlockup detector to generate a panic instead of a warning message. high-availability systems might opt for this strict method (combined with panic_timeout= boot option/sysctl), instead of generating softlockup warnings ad infinitum. also, automated tests work better if the system reboots reliably (into a safe kernel) in case of a lockup. The full spectrum of configurability is supported: boot option, sysctl option and Kconfig option. it's default-disabled. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/sysctl.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 29116652dca8..2d3b388c402d 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -727,6 +727,17 @@ static struct ctl_table kern_table[] = { }, #endif #ifdef CONFIG_DETECT_SOFTLOCKUP + { + .ctl_name = CTL_UNNUMBERED, + .procname = "softlockup_panic", + .data = &softlockup_panic, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_doulongvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + .extra2 = &one, + }, { .ctl_name = CTL_UNNUMBERED, .procname = "softlockup_thresh", -- cgit v1.3-18-gd494 From 9383d9679056e6cc4e7ff70f31da945a268238f4 Mon Sep 17 00:00:00 2001 From: Dimitri Sivanich Date: Mon, 12 May 2008 21:21:14 +0200 Subject: softlockup: fix softlockup_thresh unaligned access and disable detection at runtime Fix unaligned access errors when setting softlockup_thresh on 64 bit platforms. Allow softlockup detection to be disabled by setting softlockup_thresh <= 0. Detect that boot time softlockup detection has been disabled earlier in softlockup_tick. Signed-off-by: Dimitri Sivanich Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- include/linux/sched.h | 2 +- kernel/softlockup.c | 12 ++++++++++-- kernel/sysctl.c | 9 +++++---- 3 files changed, 16 insertions(+), 7 deletions(-) (limited to 'kernel/sysctl.c') diff --git a/include/linux/sched.h b/include/linux/sched.h index 71f5972dc48e..ea26221644e2 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -295,10 +295,10 @@ extern void spawn_softlockup_task(void); extern void touch_softlockup_watchdog(void); extern void touch_all_softlockup_watchdogs(void); extern unsigned int softlockup_panic; -extern unsigned long softlockup_thresh; extern unsigned long sysctl_hung_task_check_count; extern unsigned long sysctl_hung_task_timeout_secs; extern unsigned long sysctl_hung_task_warnings; +extern int softlockup_thresh; #else static inline void softlockup_tick(void) { diff --git a/kernel/softlockup.c b/kernel/softlockup.c index 78e0ad21cb0c..a3a0b239b7f7 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -25,7 +25,7 @@ static DEFINE_PER_CPU(unsigned long, print_timestamp); static DEFINE_PER_CPU(struct task_struct *, watchdog_task); static int __read_mostly did_panic; -unsigned long __read_mostly softlockup_thresh = 60; +int __read_mostly softlockup_thresh = 60; /* * Should we panic (and reboot, if panic_timeout= is set) when a @@ -94,6 +94,14 @@ void softlockup_tick(void) struct pt_regs *regs = get_irq_regs(); unsigned long now; + /* Is detection switched off? */ + if (!per_cpu(watchdog_task, this_cpu) || softlockup_thresh <= 0) { + /* Be sure we don't false trigger if switched back on */ + if (touch_timestamp) + per_cpu(touch_timestamp, this_cpu) = 0; + return; + } + if (touch_timestamp == 0) { touch_softlockup_watchdog(); return; @@ -104,7 +112,7 @@ void softlockup_tick(void) /* report at most once a second */ if ((print_timestamp >= touch_timestamp && print_timestamp < (touch_timestamp + 1)) || - did_panic || !per_cpu(watchdog_task, this_cpu)) { + did_panic) { return; } diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 2d3b388c402d..31c19a79738d 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -84,12 +84,13 @@ extern int latencytop_enabled; extern int sysctl_nr_open_min, sysctl_nr_open_max; /* Constants used for minimum and maximum */ -#if defined(CONFIG_DETECT_SOFTLOCKUP) || defined(CONFIG_HIGHMEM) +#ifdef CONFIG_HIGHMEM static int one = 1; #endif #ifdef CONFIG_DETECT_SOFTLOCKUP static int sixty = 60; +static int neg_one = -1; #endif #ifdef CONFIG_MMU @@ -742,11 +743,11 @@ static struct ctl_table kern_table[] = { .ctl_name = CTL_UNNUMBERED, .procname = "softlockup_thresh", .data = &softlockup_thresh, - .maxlen = sizeof(unsigned long), + .maxlen = sizeof(int), .mode = 0644, - .proc_handler = &proc_doulongvec_minmax, + .proc_handler = &proc_dointvec_minmax, .strategy = &sysctl_intvec, - .extra1 = &one, + .extra1 = &neg_one, .extra2 = &sixty, }, { -- cgit v1.3-18-gd494 From 1c4cd6dd1d0fd3057bb6b8c87460049497889d1b Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 12 May 2008 21:21:14 +0200 Subject: softlockup: fix softlockup_thresh fix Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/sysctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 31c19a79738d..a829dc8d7a9e 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -84,7 +84,7 @@ extern int latencytop_enabled; extern int sysctl_nr_open_min, sysctl_nr_open_max; /* Constants used for minimum and maximum */ -#ifdef CONFIG_HIGHMEM +#if defined(CONFIG_HIGHMEM) || defined(CONFIG_DETECT_SOFTLOCKUP) static int one = 1; #endif -- cgit v1.3-18-gd494 From 4dca10a96041f78bed11ce9e4a5cfde813ec4ccb Mon Sep 17 00:00:00 2001 From: Hiroshi Shimamoto Date: Mon, 7 Jul 2008 18:37:04 -0700 Subject: softlockup: fix invalid proc_handler for softlockup_panic The type of softlockup_panic is int, but the proc_handler is proc_doulongvec_minmax(). This handler is for unsigned long. This handler should be proc_dointvec_minmax(). Signed-off-by: Hiroshi Shimamoto Signed-off-by: Ingo Molnar --- kernel/sysctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 3e56d2f91414..ab59ac008caf 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -741,7 +741,7 @@ static struct ctl_table kern_table[] = { .data = &softlockup_panic, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = &proc_doulongvec_minmax, + .proc_handler = &proc_dointvec_minmax, .strategy = &sysctl_intvec, .extra1 = &zero, .extra2 = &one, -- cgit v1.3-18-gd494 From a1ef5adb4cad43460ebba23c5a78cf4a55bb6a5b Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 8 Jul 2008 19:00:17 +0200 Subject: remove CONFIG_KMOD from core kernel code Always compile request_module when the kernel allows modules. Signed-off-by: Johannes Berg Signed-off-by: Rusty Russell --- include/linux/kmod.h | 2 +- kernel/exec_domain.c | 2 +- kernel/kmod.c | 2 +- kernel/sysctl.c | 4 ++-- 4 files changed, 5 insertions(+), 5 deletions(-) (limited to 'kernel/sysctl.c') diff --git a/include/linux/kmod.h b/include/linux/kmod.h index 9bdb28d6660f..0509c4ce4857 100644 --- a/include/linux/kmod.h +++ b/include/linux/kmod.h @@ -25,7 +25,7 @@ #define KMOD_PATH_LEN 256 -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES /* modprobe exit status on success, -ve on error. Return value * usually useless though. */ extern int request_module(const char * name, ...) __attribute__ ((format (printf, 1, 2))); diff --git a/kernel/exec_domain.c b/kernel/exec_domain.c index a9e6bad9f706..c1ef192aa655 100644 --- a/kernel/exec_domain.c +++ b/kernel/exec_domain.c @@ -65,7 +65,7 @@ lookup_exec_domain(u_long personality) goto out; } -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES read_unlock(&exec_domains_lock); request_module("personality-%ld", pers); read_lock(&exec_domains_lock); diff --git a/kernel/kmod.c b/kernel/kmod.c index 8df97d3dfda8..90d7af1c1655 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -42,7 +42,7 @@ extern int max_threads; static struct workqueue_struct *khelper_wq; -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES /* modprobe_path is set via /proc/sys. diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 6b16e16428d8..b859e6b5a767 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -110,7 +110,7 @@ static int min_percpu_pagelist_fract = 8; static int ngroups_max = NGROUPS_MAX; -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES extern char modprobe_path[]; #endif #ifdef CONFIG_CHR_DEV_SG @@ -475,7 +475,7 @@ static struct ctl_table kern_table[] = { .proc_handler = &ftrace_enable_sysctl, }, #endif -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES { .ctl_name = KERN_MODPROBE, .procname = "modprobe", -- cgit v1.3-18-gd494