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locking/static_key: Add support for deferred static branches
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Add deferred static branches.  We can't unfortunately use the
nice trick of encapsulating the entire structure in true/false
variants, because the inside has to be either struct static_key_true
or struct static_key_false.  Use defines to pass the appropriate
members to the helpers separately.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: alexei.starovoitov@gmail.com
Cc: ard.biesheuvel@linaro.org
Cc: oss-drivers@netronome.com
Cc: yamada.masahiro@socionext.com
Link: https://lkml.kernel.org/r/20190330000854.30142-2-jakub.kicinski@netronome.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Jakub Kicinski authored and Ingo Molnar committed Apr 29, 2019
1 parent 948f837 commit ad282a8
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Showing 2 changed files with 71 additions and 10 deletions.
64 changes: 61 additions & 3 deletions include/linux/jump_label_ratelimit.h
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Original file line number Diff line number Diff line change
Expand Up @@ -12,21 +12,79 @@ struct static_key_deferred {
struct delayed_work work;
};

extern void static_key_slow_dec_deferred(struct static_key_deferred *key);
extern void static_key_deferred_flush(struct static_key_deferred *key);
struct static_key_true_deferred {
struct static_key_true key;
unsigned long timeout;
struct delayed_work work;
};

struct static_key_false_deferred {
struct static_key_false key;
unsigned long timeout;
struct delayed_work work;
};

#define static_key_slow_dec_deferred(x) \
__static_key_slow_dec_deferred(&(x)->key, &(x)->work, (x)->timeout)
#define static_branch_slow_dec_deferred(x) \
__static_key_slow_dec_deferred(&(x)->key.key, &(x)->work, (x)->timeout)

#define static_key_deferred_flush(x) \
__static_key_deferred_flush((x), &(x)->work)

extern void
__static_key_slow_dec_deferred(struct static_key *key,
struct delayed_work *work,
unsigned long timeout);
extern void __static_key_deferred_flush(void *key, struct delayed_work *work);
extern void
jump_label_rate_limit(struct static_key_deferred *key, unsigned long rl);

extern void jump_label_update_timeout(struct work_struct *work);

#define DEFINE_STATIC_KEY_DEFERRED_TRUE(name, rl) \
struct static_key_true_deferred name = { \
.key = { STATIC_KEY_INIT_TRUE }, \
.timeout = (rl), \
.work = __DELAYED_WORK_INITIALIZER((name).work, \
jump_label_update_timeout, \
0), \
}

#define DEFINE_STATIC_KEY_DEFERRED_FALSE(name, rl) \
struct static_key_false_deferred name = { \
.key = { STATIC_KEY_INIT_FALSE }, \
.timeout = (rl), \
.work = __DELAYED_WORK_INITIALIZER((name).work, \
jump_label_update_timeout, \
0), \
}

#define static_branch_deferred_inc(x) static_branch_inc(&(x)->key)

#else /* !CONFIG_JUMP_LABEL */
struct static_key_deferred {
struct static_key key;
};
struct static_key_true_deferred {
struct static_key_true key;
};
struct static_key_false_deferred {
struct static_key_false key;
};
#define DEFINE_STATIC_KEY_DEFERRED_TRUE(name, rl) \
struct static_key_true_deferred name = { STATIC_KEY_TRUE_INIT }
#define DEFINE_STATIC_KEY_DEFERRED_FALSE(name, rl) \
struct static_key_false_deferred name = { STATIC_KEY_FALSE_INIT }

#define static_branch_slow_dec_deferred(x) static_branch_dec(&(x)->key)

static inline void static_key_slow_dec_deferred(struct static_key_deferred *key)
{
STATIC_KEY_CHECK_USE(key);
static_key_slow_dec(&key->key);
}
static inline void static_key_deferred_flush(struct static_key_deferred *key)
static inline void static_key_deferred_flush(void *key)
{
STATIC_KEY_CHECK_USE(key);
}
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17 changes: 10 additions & 7 deletions kernel/jump_label.c
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Original file line number Diff line number Diff line change
Expand Up @@ -244,12 +244,13 @@ static void __static_key_slow_dec(struct static_key *key,
cpus_read_unlock();
}

static void jump_label_update_timeout(struct work_struct *work)
void jump_label_update_timeout(struct work_struct *work)
{
struct static_key_deferred *key =
container_of(work, struct static_key_deferred, work.work);
__static_key_slow_dec(&key->key, 0, NULL);
}
EXPORT_SYMBOL_GPL(jump_label_update_timeout);

void static_key_slow_dec(struct static_key *key)
{
Expand All @@ -264,19 +265,21 @@ void static_key_slow_dec_cpuslocked(struct static_key *key)
__static_key_slow_dec_cpuslocked(key, 0, NULL);
}

void static_key_slow_dec_deferred(struct static_key_deferred *key)
void __static_key_slow_dec_deferred(struct static_key *key,
struct delayed_work *work,
unsigned long timeout)
{
STATIC_KEY_CHECK_USE(key);
__static_key_slow_dec(&key->key, key->timeout, &key->work);
__static_key_slow_dec(key, timeout, work);
}
EXPORT_SYMBOL_GPL(static_key_slow_dec_deferred);
EXPORT_SYMBOL_GPL(__static_key_slow_dec_deferred);

void static_key_deferred_flush(struct static_key_deferred *key)
void __static_key_deferred_flush(void *key, struct delayed_work *work)
{
STATIC_KEY_CHECK_USE(key);
flush_delayed_work(&key->work);
flush_delayed_work(work);
}
EXPORT_SYMBOL_GPL(static_key_deferred_flush);
EXPORT_SYMBOL_GPL(__static_key_deferred_flush);

void jump_label_rate_limit(struct static_key_deferred *key,
unsigned long rl)
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