From 89e7e374dde1015d69d2d70797ae4053b14fa9db Mon Sep 17 00:00:00 2001 From: Josh Triplett Date: Fri, 29 Sep 2006 01:59:36 -0700 Subject: [PATCH] timer: add lock annotation to lock_timer_base lock_timer_base acquires a lock and returns with that lock held. Add a lock annotation to this function so that sparse can check callers for lock pairing, and so that sparse will not complain about this function since it intentionally uses the lock in this manner. Signed-off-by: Josh Triplett Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/timer.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/timer.c') diff --git a/kernel/timer.c b/kernel/timer.c index 1d7dd6267c2d..6c9fa80088ed 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -175,6 +175,7 @@ static inline void detach_timer(struct timer_list *timer, */ static tvec_base_t *lock_timer_base(struct timer_list *timer, unsigned long *flags) + __acquires(timer->base->lock) { tvec_base_t *base; -- cgit v1.2.2 From 2aae4a108dab8b8bc92270335f6e4b5c146b32ae Mon Sep 17 00:00:00 2001 From: Rolf Eike Beer Date: Fri, 29 Sep 2006 01:59:46 -0700 Subject: [PATCH] Fix kerneldoc comments in kernel/timer.c Some of the kerneldoc comments in this file are ignored since the lead-in is malformed, using either "/*" or "/***" instead of "/**". [rdunlap@xenotime.net: kerneldoc fixes] Signed-off-by: Rolf Eike Beer Acked-by: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/timer.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) (limited to 'kernel/timer.c') diff --git a/kernel/timer.c b/kernel/timer.c index 6c9fa80088ed..d644f4e9ca0c 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -136,7 +136,7 @@ static void internal_add_timer(tvec_base_t *base, struct timer_list *timer) list_add_tail(&timer->entry, vec); } -/*** +/** * init_timer - initialize a timer. * @timer: the timer to be initialized * @@ -236,7 +236,7 @@ int __mod_timer(struct timer_list *timer, unsigned long expires) EXPORT_SYMBOL(__mod_timer); -/*** +/** * add_timer_on - start a timer on a particular CPU * @timer: the timer to be added * @cpu: the CPU to start it on @@ -256,9 +256,10 @@ void add_timer_on(struct timer_list *timer, int cpu) } -/*** +/** * mod_timer - modify a timer's timeout * @timer: the timer to be modified + * @expires: new timeout in jiffies * * mod_timer is a more efficient way to update the expire field of an * active timer (if the timer is inactive it will be activated) @@ -292,7 +293,7 @@ int mod_timer(struct timer_list *timer, unsigned long expires) EXPORT_SYMBOL(mod_timer); -/*** +/** * del_timer - deactive a timer. * @timer: the timer to be deactivated * @@ -324,7 +325,10 @@ int del_timer(struct timer_list *timer) EXPORT_SYMBOL(del_timer); #ifdef CONFIG_SMP -/* +/** + * try_to_del_timer_sync - Try to deactivate a timer + * @timer: timer do del + * * This function tries to deactivate a timer. Upon successful (ret >= 0) * exit the timer is not queued and the handler is not running on any CPU. * @@ -352,7 +356,7 @@ out: return ret; } -/*** +/** * del_timer_sync - deactivate a timer and wait for the handler to finish. * @timer: the timer to be deactivated * @@ -402,15 +406,15 @@ static int cascade(tvec_base_t *base, tvec_t *tv, int index) return index; } -/*** +#define INDEX(N) ((base->timer_jiffies >> (TVR_BITS + (N) * TVN_BITS)) & TVN_MASK) + +/** * __run_timers - run all expired timers (if any) on this CPU. * @base: the timer vector to be processed. * * This function cascades all vectors and executes all expired timer * vectors. */ -#define INDEX(N) ((base->timer_jiffies >> (TVR_BITS + (N) * TVN_BITS)) & TVN_MASK) - static inline void __run_timers(tvec_base_t *base) { struct timer_list *timer; @@ -971,7 +975,7 @@ void __init timekeeping_init(void) static int timekeeping_suspended; -/* +/** * timekeeping_resume - Resumes the generic timekeeping subsystem. * @dev: unused * @@ -1107,7 +1111,7 @@ static void clocksource_adjust(struct clocksource *clock, s64 offset) clock->error -= (interval - offset) << (TICK_LENGTH_SHIFT - clock->shift); } -/* +/** * update_wall_time - Uses the current clocksource to increment the wall time * * Called from the timer interrupt, must hold a write on xtime_lock. @@ -1471,8 +1475,9 @@ asmlinkage long sys_gettid(void) return current->pid; } -/* +/** * sys_sysinfo - fill in sysinfo struct + * @info: pointer to buffer to fill */ asmlinkage long sys_sysinfo(struct sysinfo __user *info) { -- cgit v1.2.2 From 07dccf3344010f9b9df7fe725da7e73bca2992df Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Fri, 29 Sep 2006 02:00:22 -0700 Subject: [PATCH] check return value of cpu_callback Spawing ksoftirqd, migration, or watchdog, and calling init_timers_cpu() may fail with small memory. If it happens in initcalls, kernel NULL pointer dereference happens later. This patch makes crash happen immediately in such cases. It seems a bit better than getting kernel NULL pointer dereference later. Cc: Ingo Molnar Signed-off-by: Akinobu Mita Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/timer.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel/timer.c') diff --git a/kernel/timer.c b/kernel/timer.c index d644f4e9ca0c..a2cb1ecb1b28 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1694,8 +1694,10 @@ static struct notifier_block __cpuinitdata timers_nb = { void __init init_timers(void) { - timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE, + int err = timer_cpu_notify(&timers_nb, (unsigned long)CPU_UP_PREPARE, (void *)(long)smp_processor_id()); + + BUG_ON(err == NOTIFY_BAD); register_cpu_notifier(&timers_nb); open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL); } -- cgit v1.2.2 From 3171a0305d62e6627a24bff35af4f997e4988a80 Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Fri, 29 Sep 2006 02:00:32 -0700 Subject: [PATCH] simplify update_times (avoid jiffies/jiffies_64 aliasing problem) Pass ticks to do_timer() and update_times(), and adjust x86_64 and s390 timer interrupt handler with this change. Currently update_times() calculates ticks by "jiffies - wall_jiffies", but callers of do_timer() should know how many ticks to update. Passing ticks get rid of this redundant calculation. Also there are another redundancy pointed out by Martin Schwidefsky. This cleanup make a barrier added by 5aee405c662ca644980c184774277fc6d0769a84 needless. So this patch removes it. As a bonus, this cleanup make wall_jiffies can be removed easily, since now wall_jiffies is always synced with jiffies. (This patch does not really remove wall_jiffies. It would be another cleanup patch) Signed-off-by: Atsushi Nemoto Cc: Martin Schwidefsky Cc: "Eric W. Biederman" Cc: Thomas Gleixner Cc: Ingo Molnar Cc: john stultz Cc: Andi Kleen Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Richard Henderson Cc: Ivan Kokshaysky Acked-by: Russell King Cc: Ian Molton Cc: Mikael Starvik Acked-by: David Howells Cc: Yoshinori Sato Cc: Hirokazu Takata Acked-by: Ralf Baechle Cc: Kyle McMartin Cc: Heiko Carstens Cc: Martin Schwidefsky Cc: Paul Mundt Cc: Kazumoto Kojima Cc: Richard Curnow Cc: William Lee Irwin III Cc: "David S. Miller" Cc: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Cc: Miles Bader Cc: Chris Zankel Acked-by: "Luck, Tony" Cc: Geert Uytterhoeven Cc: Roman Zippel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/timer.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) (limited to 'kernel/timer.c') diff --git a/kernel/timer.c b/kernel/timer.c index a2cb1ecb1b28..4f55622b0d38 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1222,10 +1222,8 @@ static inline void calc_load(unsigned long ticks) unsigned long active_tasks; /* fixed-point */ static int count = LOAD_FREQ; - count -= ticks; - if (count < 0) { - count += LOAD_FREQ; - active_tasks = count_active_tasks(); + active_tasks = count_active_tasks(); + for (count -= ticks; count < 0; count += LOAD_FREQ) { CALC_LOAD(avenrun[0], EXP_1, active_tasks); CALC_LOAD(avenrun[1], EXP_5, active_tasks); CALC_LOAD(avenrun[2], EXP_15, active_tasks); @@ -1270,11 +1268,8 @@ void run_local_timers(void) * Called by the timer interrupt. xtime_lock must already be taken * by the timer IRQ! */ -static inline void update_times(void) +static inline void update_times(unsigned long ticks) { - unsigned long ticks; - - ticks = jiffies - wall_jiffies; wall_jiffies += ticks; update_wall_time(); calc_load(ticks); @@ -1286,12 +1281,10 @@ static inline void update_times(void) * jiffies is defined in the linker script... */ -void do_timer(struct pt_regs *regs) +void do_timer(unsigned long ticks) { - jiffies_64++; - /* prevent loading jiffies before storing new jiffies_64 value. */ - barrier(); - update_times(); + jiffies_64 += ticks; + update_times(ticks); } #ifdef __ARCH_WANT_SYS_ALARM -- cgit v1.2.2