Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Tue, 29 May 2018 10:09:51 +0200 | Subject | Re: [PATCH 1/2] kernel/SRCU: provide a static initializer |
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On Fri, May 25, 2018 at 12:19 PM, Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote: > There are macros for static initializer for the three out of four > possible notifier types, that are: > ATOMIC_NOTIFIER_HEAD() > BLOCKING_NOTIFIER_HEAD() > RAW_NOTIFIER_HEAD() > > This patch provides a static initilizer for the forth type to make it > complete. > > Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
I cannot apply this without an ACK from Paul.
> --- > include/linux/notifier.h | 34 +++++++++++++++++++++++++++++----- > include/linux/srcutiny.h | 6 +++--- > include/linux/srcutree.h | 6 +++--- > 3 files changed, 35 insertions(+), 11 deletions(-) > > diff --git a/include/linux/notifier.h b/include/linux/notifier.h > index 6d731110e0db..f35c7bf76143 100644 > --- a/include/linux/notifier.h > +++ b/include/linux/notifier.h > @@ -43,9 +43,7 @@ > * in srcu_notifier_call_chain(): no cache bounces and no memory barriers. > * As compensation, srcu_notifier_chain_unregister() is rather expensive. > * SRCU notifier chains should be used when the chain will be called very > - * often but notifier_blocks will seldom be removed. Also, SRCU notifier > - * chains are slightly more difficult to use because they require special > - * runtime initialization. > + * often but notifier_blocks will seldom be removed. > */ > > struct notifier_block; > @@ -91,7 +89,7 @@ struct srcu_notifier_head { > (name)->head = NULL; \ > } while (0) > > -/* srcu_notifier_heads must be initialized and cleaned up dynamically */ > +/* srcu_notifier_heads must be cleaned up dynamically */ > extern void srcu_init_notifier_head(struct srcu_notifier_head *nh); > #define srcu_cleanup_notifier_head(name) \ > cleanup_srcu_struct(&(name)->srcu); > @@ -104,7 +102,13 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh); > .head = NULL } > #define RAW_NOTIFIER_INIT(name) { \ > .head = NULL } > -/* srcu_notifier_heads cannot be initialized statically */ > + > +#define SRCU_NOTIFIER_INIT(name, pcpu) \ > + { \ > + .mutex = __MUTEX_INITIALIZER(name.mutex), \ > + .head = NULL, \ > + .srcu = __SRCU_STRUCT_INIT(name.srcu, pcpu), \ > + } > > #define ATOMIC_NOTIFIER_HEAD(name) \ > struct atomic_notifier_head name = \ > @@ -116,6 +120,26 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh); > struct raw_notifier_head name = \ > RAW_NOTIFIER_INIT(name) > > +#ifdef CONFIG_TREE_SRCU > +#define _SRCU_NOTIFIER_HEAD(name, mod) \ > + static DEFINE_PER_CPU(struct srcu_data, \ > + name##_head_srcu_data); \ > + mod struct srcu_notifier_head name = \ > + SRCU_NOTIFIER_INIT(name, name##_head_srcu_data) > + > +#else > +#define _SRCU_NOTIFIER_HEAD(name, mod) \ > + mod struct srcu_notifier_head name = \ > + SRCU_NOTIFIER_INIT(name, name) > + > +#endif > + > +#define SRCU_NOTIFIER_HEAD(name) \ > + _SRCU_NOTIFIER_HEAD(name, /* not static */) > + > +#define SRCU_NOTIFIER_HEAD_STATIC(name) \ > + _SRCU_NOTIFIER_HEAD(name, static) > + > #ifdef __KERNEL__ > > extern int atomic_notifier_chain_register(struct atomic_notifier_head *nh, > diff --git a/include/linux/srcutiny.h b/include/linux/srcutiny.h > index 261471f407a5..f41d2fb09f87 100644 > --- a/include/linux/srcutiny.h > +++ b/include/linux/srcutiny.h > @@ -43,7 +43,7 @@ struct srcu_struct { > > void srcu_drive_gp(struct work_struct *wp); > > -#define __SRCU_STRUCT_INIT(name) \ > +#define __SRCU_STRUCT_INIT(name, __ignored) \ > { \ > .srcu_wq = __SWAIT_QUEUE_HEAD_INITIALIZER(name.srcu_wq), \ > .srcu_cb_tail = &name.srcu_cb_head, \ > @@ -56,9 +56,9 @@ void srcu_drive_gp(struct work_struct *wp); > * Tree SRCU, which needs some per-CPU data. > */ > #define DEFINE_SRCU(name) \ > - struct srcu_struct name = __SRCU_STRUCT_INIT(name) > + struct srcu_struct name = __SRCU_STRUCT_INIT(name, name) > #define DEFINE_STATIC_SRCU(name) \ > - static struct srcu_struct name = __SRCU_STRUCT_INIT(name) > + static struct srcu_struct name = __SRCU_STRUCT_INIT(name, name) > > void synchronize_srcu(struct srcu_struct *sp); > > diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h > index 4eda108abee0..745d4ca4dd50 100644 > --- a/include/linux/srcutree.h > +++ b/include/linux/srcutree.h > @@ -104,9 +104,9 @@ struct srcu_struct { > #define SRCU_STATE_SCAN1 1 > #define SRCU_STATE_SCAN2 2 > > -#define __SRCU_STRUCT_INIT(name) \ > +#define __SRCU_STRUCT_INIT(name, pcpu_name) \ > { \ > - .sda = &name##_srcu_data, \ > + .sda = &pcpu_name, \ > .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ > .srcu_gp_seq_needed = 0 - 1, \ > __SRCU_DEP_MAP_INIT(name) \ > @@ -133,7 +133,7 @@ struct srcu_struct { > */ > #define __DEFINE_SRCU(name, is_static) \ > static DEFINE_PER_CPU(struct srcu_data, name##_srcu_data);\ > - is_static struct srcu_struct name = __SRCU_STRUCT_INIT(name) > + is_static struct srcu_struct name = __SRCU_STRUCT_INIT(name, name##_srcu_data) > #define DEFINE_SRCU(name) __DEFINE_SRCU(name, /* not static */) > #define DEFINE_STATIC_SRCU(name) __DEFINE_SRCU(name, static) > > -- > 2.17.0 >
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