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/*
* CDDL HEADER START
*
* This file and its contents are supplied under the terms of the
* Common Development and Distribution License ("CDDL"), version 1.0.
* You may only use this file in accordance with the terms of version
* 1.0 of the CDDL.
*
* A full copy of the text of the CDDL should have accompanied this
* source. A copy of the CDDL is also available via the Internet at
* http://www.illumos.org/license/CDDL.
*
* CDDL HEADER END
*/
/*
* wmsum counters are a reduced version of aggsum counters, optimized for
* write-mostly scenarios. They do not provide optimized read functions,
* but instead allow much cheaper add function. The primary usage is
* infrequently read statistic counters, not requiring exact precision.
*
* The Linux implementation is directly mapped into percpu_counter KPI.
*/
#ifndef _SYS_WMSUM_H
#define _SYS_WMSUM_H
#include <linux/percpu_counter.h>
#ifdef __cplusplus
extern "C" {
#endif
typedef struct percpu_counter wmsum_t;
static inline void
wmsum_init(wmsum_t *ws, uint64_t value)
{
#ifdef HAVE_PERCPU_COUNTER_INIT_WITH_GFP
percpu_counter_init(ws, value, GFP_KERNEL);
#else
percpu_counter_init(ws, value);
#endif
}
static inline void
wmsum_fini(wmsum_t *ws)
{
percpu_counter_destroy(ws);
}
static inline uint64_t
wmsum_value(wmsum_t *ws)
{
return (percpu_counter_sum(ws));
}
static inline void
wmsum_add(wmsum_t *ws, int64_t delta)
{
#ifdef HAVE_PERCPU_COUNTER_ADD_BATCH
percpu_counter_add_batch(ws, delta, INT_MAX / 2);
#else
__percpu_counter_add(ws, delta, INT_MAX / 2);
#endif
}
#ifdef __cplusplus
}
#endif
#endif /* _SYS_WMSUM_H */
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