From d0959024d8fb6555ba8bfdc6624cc7b7c2e675fd Mon Sep 17 00:00:00 2001 From: Richard Kennedy Date: Wed, 20 Oct 2010 15:57:30 -0700 Subject: timer_list: Remove alignment padding on 64 bit when CONFIG_TIMER_STATS Reorder struct timer_list to remove 8 bytes of alignment padding on 64 bit builds when CONFIG_TIMER_STATS is selected. timer_list is widely used across the kernel so many structures will benefit and shrink in size. For example, with my config on x86_64 per_cpu_dm_data shrinks from 136 to 128 bytes and ahci_port_priv shrinks from 1032 to 968 bytes. Signed-off-by: Richard Kennedy Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- include/linux/timer.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/timer.h') diff --git a/include/linux/timer.h b/include/linux/timer.h index 38cf093ef62c..f3dccdb44f95 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -24,9 +24,9 @@ struct timer_list { int slack; #ifdef CONFIG_TIMER_STATS + int start_pid; void *start_site; char start_comm[16]; - int start_pid; #endif #ifdef CONFIG_LOCKDEP struct lockdep_map lockdep_map; -- cgit v1.2.3-71-gd317 From aaabe31c25a439b92cc281b14ca18b85bae7e7a6 Mon Sep 17 00:00:00 2001 From: Changli Gao Date: Wed, 20 Oct 2010 15:57:30 -0700 Subject: timer: Initialize the field slack of timer_list TIMER_INITIALIZER() should initialize the field slack of timer_list as __init_timer() does. Signed-off-by: Changli Gao Cc: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- include/linux/timer.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/timer.h') diff --git a/include/linux/timer.h b/include/linux/timer.h index f3dccdb44f95..1794674c1a52 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -54,6 +54,7 @@ extern struct tvec_base boot_tvec_bases; .expires = (_expires), \ .data = (_data), \ .base = &boot_tvec_bases, \ + .slack = -1, \ __TIMER_LOCKDEP_MAP_INITIALIZER( \ __FILE__ ":" __stringify(__LINE__)) \ } -- cgit v1.2.3-71-gd317 From dd6414b50fa2b1cd247a8aa8f8bd42414b7453e1 Mon Sep 17 00:00:00 2001 From: Phil Carmody Date: Wed, 20 Oct 2010 15:57:33 -0700 Subject: timer: Permit statically-declared work with deferrable timers Currently, you have to just define a delayed_work uninitialised, and then initialise it before first use. That's a tad clumsy. At risk of playing mind-games with the compiler, fooling it into doing pointer arithmetic with compile-time-constants, this lets clients properly initialise delayed work with deferrable timers statically. This patch was inspired by the issues which lead Artem Bityutskiy to commit 8eab945c5616fc984 ("sunrpc: make the cache cleaner workqueue deferrable"). Signed-off-by: Phil Carmody Acked-by: Artem Bityutskiy Cc: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- include/linux/timer.h | 25 +++++++++++++++++++++++++ include/linux/workqueue.h | 8 ++++++++ kernel/timer.c | 15 +-------------- 3 files changed, 34 insertions(+), 14 deletions(-) (limited to 'include/linux/timer.h') diff --git a/include/linux/timer.h b/include/linux/timer.h index 1794674c1a52..cbfb7a355d30 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -48,6 +48,18 @@ extern struct tvec_base boot_tvec_bases; #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn) #endif +/* + * Note that all tvec_bases are 2 byte aligned and lower bit of + * base in timer_list is guaranteed to be zero. Use the LSB to + * indicate whether the timer is deferrable. + * + * A deferrable timer will work normally when the system is busy, but + * will not cause a CPU to come out of idle just to service it; instead, + * the timer will be serviced when the CPU eventually wakes up with a + * subsequent non-deferrable timer. + */ +#define TBASE_DEFERRABLE_FLAG (0x1) + #define TIMER_INITIALIZER(_function, _expires, _data) { \ .entry = { .prev = TIMER_ENTRY_STATIC }, \ .function = (_function), \ @@ -59,6 +71,19 @@ extern struct tvec_base boot_tvec_bases; __FILE__ ":" __stringify(__LINE__)) \ } +#define TBASE_MAKE_DEFERRED(ptr) ((struct tvec_base *) \ + ((unsigned char *)(ptr) + TBASE_DEFERRABLE_FLAG)) + +#define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data) {\ + .entry = { .prev = TIMER_ENTRY_STATIC }, \ + .function = (_function), \ + .expires = (_expires), \ + .data = (_data), \ + .base = TBASE_MAKE_DEFERRED(&boot_tvec_bases), \ + __TIMER_LOCKDEP_MAP_INITIALIZER( \ + __FILE__ ":" __stringify(__LINE__)) \ + } + #define DEFINE_TIMER(_name, _function, _expires, _data) \ struct timer_list _name = \ TIMER_INITIALIZER(_function, _expires, _data) diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index f11100f96482..88238c15ec3e 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -127,12 +127,20 @@ struct execute_work { .timer = TIMER_INITIALIZER(NULL, 0, 0), \ } +#define __DEFERRED_WORK_INITIALIZER(n, f) { \ + .work = __WORK_INITIALIZER((n).work, (f)), \ + .timer = TIMER_DEFERRED_INITIALIZER(NULL, 0, 0), \ + } + #define DECLARE_WORK(n, f) \ struct work_struct n = __WORK_INITIALIZER(n, f) #define DECLARE_DELAYED_WORK(n, f) \ struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f) +#define DECLARE_DEFERRED_WORK(n, f) \ + struct delayed_work n = __DEFERRED_WORK_INITIALIZER(n, f) + /* * initialize a work item's function pointer */ diff --git a/kernel/timer.c b/kernel/timer.c index 97bf05baade7..72853b256ff2 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -88,18 +88,6 @@ struct tvec_base boot_tvec_bases; EXPORT_SYMBOL(boot_tvec_bases); static DEFINE_PER_CPU(struct tvec_base *, tvec_bases) = &boot_tvec_bases; -/* - * Note that all tvec_bases are 2 byte aligned and lower bit of - * base in timer_list is guaranteed to be zero. Use the LSB to - * indicate whether the timer is deferrable. - * - * A deferrable timer will work normally when the system is busy, but - * will not cause a CPU to come out of idle just to service it; instead, - * the timer will be serviced when the CPU eventually wakes up with a - * subsequent non-deferrable timer. - */ -#define TBASE_DEFERRABLE_FLAG (0x1) - /* Functions below help us manage 'deferrable' flag */ static inline unsigned int tbase_get_deferrable(struct tvec_base *base) { @@ -113,8 +101,7 @@ static inline struct tvec_base *tbase_get_base(struct tvec_base *base) static inline void timer_set_deferrable(struct timer_list *timer) { - timer->base = ((struct tvec_base *)((unsigned long)(timer->base) | - TBASE_DEFERRABLE_FLAG)); + timer->base = TBASE_MAKE_DEFERRED(timer->base); } static inline void -- cgit v1.2.3-71-gd317 From 6f1bc451e6a79470b122a37ee1fc6bbca450f444 Mon Sep 17 00:00:00 2001 From: Yong Zhang Date: Wed, 20 Oct 2010 15:57:31 -0700 Subject: timer: Make try_to_del_timer_sync() the same on SMP and UP On UP try_to_del_timer_sync() is mapped to del_timer() which does not take the running timer callback into account, so it has different semantics. Remove the SMP dependency of try_to_del_timer_sync() by using base->running_timer in the UP case as well. [ tglx: Removed set_running_timer() inline and tweaked the changelog ] Signed-off-by: Yong Zhang Cc: Ingo Molnar Cc: Peter Zijlstra Acked-by: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner --- include/linux/timer.h | 4 ++-- kernel/timer.c | 17 +++-------------- 2 files changed, 5 insertions(+), 16 deletions(-) (limited to 'include/linux/timer.h') diff --git a/include/linux/timer.h b/include/linux/timer.h index cbfb7a355d30..6abd9138beda 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -274,11 +274,11 @@ static inline void timer_stats_timer_clear_start_info(struct timer_list *timer) extern void add_timer(struct timer_list *timer); +extern int try_to_del_timer_sync(struct timer_list *timer); + #ifdef CONFIG_SMP - extern int try_to_del_timer_sync(struct timer_list *timer); extern int del_timer_sync(struct timer_list *timer); #else -# define try_to_del_timer_sync(t) del_timer(t) # define del_timer_sync(t) del_timer(t) #endif diff --git a/kernel/timer.c b/kernel/timer.c index 72853b256ff2..47b86c1e3226 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -330,15 +330,6 @@ void set_timer_slack(struct timer_list *timer, int slack_hz) } EXPORT_SYMBOL_GPL(set_timer_slack); - -static inline void set_running_timer(struct tvec_base *base, - struct timer_list *timer) -{ -#ifdef CONFIG_SMP - base->running_timer = timer; -#endif -} - static void internal_add_timer(struct tvec_base *base, struct timer_list *timer) { unsigned long expires = timer->expires; @@ -923,15 +914,12 @@ 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. - * - * It must not be called from interrupt contexts. */ int try_to_del_timer_sync(struct timer_list *timer) { @@ -960,6 +948,7 @@ out: } EXPORT_SYMBOL(try_to_del_timer_sync); +#ifdef CONFIG_SMP /** * del_timer_sync - deactivate a timer and wait for the handler to finish. * @timer: the timer to be deactivated @@ -1098,7 +1087,7 @@ static inline void __run_timers(struct tvec_base *base) timer_stats_account_timer(timer); - set_running_timer(base, timer); + base->running_timer = timer; detach_timer(timer, 1); spin_unlock_irq(&base->lock); @@ -1106,7 +1095,7 @@ static inline void __run_timers(struct tvec_base *base) spin_lock_irq(&base->lock); } } - set_running_timer(base, NULL); + base->running_timer = NULL; spin_unlock_irq(&base->lock); } -- cgit v1.2.3-71-gd317