srcu: Move grace-period fields from srcu_struct to srcu_usage

This commit moves the ->srcu_gp_seq, ->srcu_gp_seq_needed,
->srcu_gp_seq_needed_exp, ->srcu_gp_start, and ->srcu_last_gp_end fields
from the srcu_struct structure to the srcu_usage structure to reduce
the size of the former in order to improve cache locality.

Suggested-by: Christoph Hellwig <hch@lst.de>
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Tested-by: "Zhang, Qiang1" <qiang1.zhang@intel.com>
Tested-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit is contained in:
Paul E. McKenney
2023-03-17 19:30:50 -07:00
parent e3a6ab25cf
commit 03200b5ca3
2 changed files with 77 additions and 76 deletions

View File

@@ -68,6 +68,11 @@ struct srcu_usage {
struct mutex srcu_cb_mutex; /* Serialize CB preparation. */
spinlock_t __private lock; /* Protect counters and size state. */
struct mutex srcu_gp_mutex; /* Serialize GP work. */
unsigned long srcu_gp_seq; /* Grace-period seq #. */
unsigned long srcu_gp_seq_needed; /* Latest gp_seq needed. */
unsigned long srcu_gp_seq_needed_exp; /* Furthest future exp GP. */
unsigned long srcu_gp_start; /* Last GP start timestamp (jiffies) */
unsigned long srcu_last_gp_end; /* Last GP end timestamp (ns) */
};
/*
@@ -75,11 +80,6 @@ struct srcu_usage {
*/
struct srcu_struct {
unsigned int srcu_idx; /* Current rdr array element. */
unsigned long srcu_gp_seq; /* Grace-period seq #. */
unsigned long srcu_gp_seq_needed; /* Latest gp_seq needed. */
unsigned long srcu_gp_seq_needed_exp; /* Furthest future exp GP. */
unsigned long srcu_gp_start; /* Last GP start timestamp (jiffies) */
unsigned long srcu_last_gp_end; /* Last GP end timestamp (ns) */
unsigned long srcu_size_jiffies; /* Current contention-measurement interval. */
unsigned long srcu_n_lock_retries; /* Contention events in current interval. */
unsigned long srcu_n_exp_nodelay; /* # expedited no-delays in current GP phase. */
@@ -115,8 +115,13 @@ struct srcu_struct {
#define SRCU_STATE_SCAN1 1
#define SRCU_STATE_SCAN2 2
#define __SRCU_STRUCT_INIT_COMMON(name, usage_name) \
#define __SRCU_USAGE_INIT(name) \
{ \
.lock = __SPIN_LOCK_UNLOCKED(name.lock), \
.srcu_gp_seq_needed = -1UL, \
}
#define __SRCU_STRUCT_INIT_COMMON(name, usage_name) \
.work = __DELAYED_WORK_INITIALIZER(name.work, NULL, 0), \
.srcu_sup = &usage_name, \
__SRCU_DEP_MAP_INIT(name)
@@ -153,9 +158,7 @@ struct srcu_struct {
*/
#ifdef MODULE
# define __DEFINE_SRCU(name, is_static) \
static struct srcu_usage name##_srcu_usage = { \
.lock = __SPIN_LOCK_UNLOCKED(name.lock), \
}; \
static struct srcu_usage name##_srcu_usage = __SRCU_USAGE_INIT(name##_srcu_usage); \
is_static struct srcu_struct name = __SRCU_STRUCT_INIT_MODULE(name, name##_srcu_usage); \
extern struct srcu_struct * const __srcu_struct_##name; \
struct srcu_struct * const __srcu_struct_##name \
@@ -163,9 +166,7 @@ struct srcu_struct {
#else
# define __DEFINE_SRCU(name, is_static) \
static DEFINE_PER_CPU(struct srcu_data, name##_srcu_data); \
static struct srcu_usage name##_srcu_usage = { \
.lock = __SPIN_LOCK_UNLOCKED(name.lock), \
}; \
static struct srcu_usage name##_srcu_usage = __SRCU_USAGE_INIT(name##_srcu_usage); \
is_static struct srcu_struct name = \
__SRCU_STRUCT_INIT(name, name##_srcu_usage, name##_srcu_data)
#endif