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Diffstat (limited to 'usr/src/uts/common/sys/cpu_uarray.h')
| -rw-r--r-- | usr/src/uts/common/sys/cpu_uarray.h | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/usr/src/uts/common/sys/cpu_uarray.h b/usr/src/uts/common/sys/cpu_uarray.h new file mode 100644 index 0000000000..9cad772597 --- /dev/null +++ b/usr/src/uts/common/sys/cpu_uarray.h @@ -0,0 +1,81 @@ +/* + * 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. + */ + +/* + * Copyright (c) 2018, Joyent, Inc. + */ + +/* + * Use a cpu_uarray_t for an array of uint64_t values that are written on a + * per-CPU basis. We align each CPU on a 128-byte boundary (so two cachelines). + * It's not clear why, but this can have a significant effect in multi-socket + * systems running certain benchmarks on a relatively current Intel system. + * + * So the layout is like this, for example: + * + * 0: STAT1 for CPU 0 + * 8: STAT2 for CPU 0 + * 16: STAT3 for CPU 0 + * 24: padding + * 128: STAT1 for CPU 1 + * 136: STAT2 for CPU 1 + * ... + * + * At collection time, cpu_uarray_sum() can be used to sum the given value index + * across all CPUs, or cpu_uarray_sum_all() sums all stats across all CPUs. + * The summation is done such that it saturates at UINT64_MAX. + */ + +#ifndef _SYS_CPU_UARRAY_H +#define _SYS_CPU_UARRAY_H + +#include <sys/types.h> + +#ifdef __cplusplus +extern "C" { +#endif + +#ifdef _KERNEL + +/* + * Trying to include sysmacros.h for P2ROUNDUP() here is just too painful. + */ +#define CUA_ROUNDUP(x, align) (-(-(x) & -(align))) +#define CUA_ALIGN (128) +#define CUA_CPU_STRIDE(nr_items) \ + CUA_ROUNDUP((nr_items), CUA_ALIGN / sizeof (uint64_t)) +#define CUA_INDEX(nr_items, c, i) (((c) * CUA_CPU_STRIDE(nr_items)) + (i)) + +#define CPU_UARRAY_VAL(cua, cpu_index, stat_index) \ + ((cua)->cu_vals[CUA_INDEX((cua)->cu_nr_items, cpu_index, stat_index)]) + +typedef struct { + uint64_t cu_nr_items; + char cu_pad[CUA_ALIGN - sizeof (uint64_t)]; +#ifdef __lint + volatile uint64_t cu_vals[1]; +#else + volatile uint64_t cu_vals[]; +#endif +} cpu_uarray_t __aligned(CUA_ALIGN); + +extern cpu_uarray_t *cpu_uarray_zalloc(size_t, int); +extern void cpu_uarray_free(cpu_uarray_t *); +extern uint64_t cpu_uarray_sum(cpu_uarray_t *, size_t); +extern uint64_t cpu_uarray_sum_all(cpu_uarray_t *); + +#endif /* _KERNEL */ + +#ifdef __cplusplus +} +#endif + +#endif /* _SYS_CPU_UARRAY_H */ |