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KAGA-KOKOingomolnar
KAGA-KOKO
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ingomolnar
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timers: Make 'pinned' a timer property
We want to move the timer migration logic from a 'push' to a 'pull' model. Under the current 'push' model pinned timers are handled via a runtime API variant: mod_timer_pinned(). The 'pull' model requires us to store the pinned attribute of a timer in the timer_list structure itself, as a new TIMER_PINNED bit in timer->flags. This flag must be set at initialization time and the timer APIs recognize the flag. This patch: - Implements the new flag and associated new-style initialization methods - makes mod_timer() recognize new-style pinned timers, - and adds some migration helper facility to allow step by step conversion of old-style to new-style pinned timers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Chris Mason <clm@fb.com> Cc: Eric Dumazet <edumazet@google.com> Cc: George Spelvin <linux@sciencehorizons.net> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160704094341.049338558@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
1 parent a99cde4 commit e675447

2 files changed

Lines changed: 27 additions & 8 deletions

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‎include/linux/timer.h‎

Lines changed: 22 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -62,7 +62,8 @@ struct timer_list {
6262
#define TIMER_MIGRATING 0x00080000
6363
#define TIMER_BASEMASK (TIMER_CPUMASK | TIMER_MIGRATING)
6464
#define TIMER_DEFERRABLE 0x00100000
65-
#define TIMER_IRQSAFE 0x00200000
65+
#define TIMER_PINNED 0x00200000
66+
#define TIMER_IRQSAFE 0x00400000
6667

6768
#define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \
6869
.entry = { .next = TIMER_ENTRY_STATIC }, \
@@ -78,9 +79,15 @@ struct timer_list {
7879
#define TIMER_INITIALIZER(_function, _expires, _data) \
7980
__TIMER_INITIALIZER((_function), (_expires), (_data), 0)
8081

82+
#define TIMER_PINNED_INITIALIZER(_function, _expires, _data) \
83+
__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_PINNED)
84+
8185
#define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data) \
8286
__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE)
8387

88+
#define TIMER_PINNED_DEFERRED_INITIALIZER(_function, _expires, _data) \
89+
__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE | TIMER_PINNED)
90+
8491
#define DEFINE_TIMER(_name, _function, _expires, _data) \
8592
struct timer_list _name = \
8693
TIMER_INITIALIZER(_function, _expires, _data)
@@ -124,8 +131,12 @@ static inline void init_timer_on_stack_key(struct timer_list *timer,
124131

125132
#define init_timer(timer) \
126133
__init_timer((timer), 0)
134+
#define init_timer_pinned(timer) \
135+
__init_timer((timer), TIMER_PINNED)
127136
#define init_timer_deferrable(timer) \
128137
__init_timer((timer), TIMER_DEFERRABLE)
138+
#define init_timer_pinned_deferrable(timer) \
139+
__init_timer((timer), TIMER_DEFERRABLE | TIMER_PINNED)
129140
#define init_timer_on_stack(timer) \
130141
__init_timer_on_stack((timer), 0)
131142

@@ -145,12 +156,20 @@ static inline void init_timer_on_stack_key(struct timer_list *timer,
145156

146157
#define setup_timer(timer, fn, data) \
147158
__setup_timer((timer), (fn), (data), 0)
159+
#define setup_pinned_timer(timer, fn, data) \
160+
__setup_timer((timer), (fn), (data), TIMER_PINNED)
148161
#define setup_deferrable_timer(timer, fn, data) \
149162
__setup_timer((timer), (fn), (data), TIMER_DEFERRABLE)
163+
#define setup_pinned_deferrable_timer(timer, fn, data) \
164+
__setup_timer((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
150165
#define setup_timer_on_stack(timer, fn, data) \
151166
__setup_timer_on_stack((timer), (fn), (data), 0)
167+
#define setup_pinned_timer_on_stack(timer, fn, data) \
168+
__setup_timer_on_stack((timer), (fn), (data), TIMER_PINNED)
152169
#define setup_deferrable_timer_on_stack(timer, fn, data) \
153170
__setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE)
171+
#define setup_pinned_deferrable_timer_on_stack(timer, fn, data) \
172+
__setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
154173

155174
/**
156175
* timer_pending - is a timer pending?
@@ -175,8 +194,8 @@ extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires);
175194

176195
extern void set_timer_slack(struct timer_list *time, int slack_hz);
177196

178-
#define TIMER_NOT_PINNED 0
179-
#define TIMER_PINNED 1
197+
#define MOD_TIMER_NOT_PINNED 0
198+
#define MOD_TIMER_PINNED 1
180199
/*
181200
* The jiffies value which is added to now, when there is no timer
182201
* in the timer wheel:

‎kernel/time/timer.c‎

Lines changed: 5 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -782,7 +782,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
782782

783783
debug_activate(timer, expires);
784784

785-
new_base = get_target_base(base, pinned);
785+
new_base = get_target_base(base, pinned || timer->flags & TIMER_PINNED);
786786

787787
if (base != new_base) {
788788
/*
@@ -825,7 +825,7 @@ __mod_timer(struct timer_list *timer, unsigned long expires,
825825
*/
826826
int mod_timer_pending(struct timer_list *timer, unsigned long expires)
827827
{
828-
return __mod_timer(timer, expires, true, TIMER_NOT_PINNED);
828+
return __mod_timer(timer, expires, true, MOD_TIMER_NOT_PINNED);
829829
}
830830
EXPORT_SYMBOL(mod_timer_pending);
831831

@@ -900,7 +900,7 @@ int mod_timer(struct timer_list *timer, unsigned long expires)
900900
if (timer_pending(timer) && timer->expires == expires)
901901
return 1;
902902

903-
return __mod_timer(timer, expires, false, TIMER_NOT_PINNED);
903+
return __mod_timer(timer, expires, false, MOD_TIMER_NOT_PINNED);
904904
}
905905
EXPORT_SYMBOL(mod_timer);
906906

@@ -928,7 +928,7 @@ int mod_timer_pinned(struct timer_list *timer, unsigned long expires)
928928
if (timer->expires == expires && timer_pending(timer))
929929
return 1;
930930

931-
return __mod_timer(timer, expires, false, TIMER_PINNED);
931+
return __mod_timer(timer, expires, false, MOD_TIMER_PINNED);
932932
}
933933
EXPORT_SYMBOL(mod_timer_pinned);
934934

@@ -1512,7 +1512,7 @@ signed long __sched schedule_timeout(signed long timeout)
15121512
expire = timeout + jiffies;
15131513

15141514
setup_timer_on_stack(&timer, process_timeout, (unsigned long)current);
1515-
__mod_timer(&timer, expire, false, TIMER_NOT_PINNED);
1515+
__mod_timer(&timer, expire, false, MOD_TIMER_NOT_PINNED);
15161516
schedule();
15171517
del_singleshot_timer_sync(&timer);
15181518

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