1 /* 2 * This file and its contents are supplied under the terms of the 3 * Common Development and Distribution License ("CDDL"), version 1.0. 4 * You may only use this file in accordance with the terms of version 5 * 1.0 of the CDDL. 6 * 7 * A full copy of the text of the CDDL should have accompanied this 8 * source. A copy of the CDDL is also available via the Internet at 9 * http://www.illumos.org/license/CDDL. 10 */ 11 12 /* 13 * Copyright (c) 2018, Joyent, Inc. 14 */ 15 16 /* 17 * Use a cpu_uarray_t for an array of uint64_t values that are written on a 18 * per-CPU basis. We align each CPU on a 128-byte boundary (so two cachelines). 19 * It's not clear why, but this can have a significant effect in multi-socket 20 * systems running certain benchmarks on a relatively current Intel system. 21 * 22 * So the layout is like this, for example: 23 * 24 * 0: STAT1 for CPU 0 25 * 8: STAT2 for CPU 0 26 * 16: STAT3 for CPU 0 27 * 24: padding 28 * 128: STAT1 for CPU 1 29 * 136: STAT2 for CPU 1 30 * ... 31 * 32 * At collection time, cpu_uarray_sum() can be used to sum the given value index 33 * across all CPUs, or cpu_uarray_sum_all() sums all stats across all CPUs. 34 * The summation is done such that it saturates at UINT64_MAX. 35 */ 36 37 #ifndef _SYS_CPU_UARRAY_H 38 #define _SYS_CPU_UARRAY_H 39 40 #include <sys/types.h> 41 42 #ifdef __cplusplus 43 extern "C" { 44 #endif 45 46 #ifdef _KERNEL 47 48 /* 49 * Trying to include sysmacros.h for P2ROUNDUP() here is just too painful. 50 */ 51 #define CUA_ROUNDUP(x, align) (-(-(x) & -(align))) 52 #define CUA_ALIGN (128) 53 #define CUA_CPU_STRIDE(nr_items) \ 54 CUA_ROUNDUP((nr_items), CUA_ALIGN / sizeof (uint64_t)) 55 #define CUA_INDEX(nr_items, c, i) (((c) * CUA_CPU_STRIDE(nr_items)) + (i)) 56 57 #define CPU_UARRAY_VAL(cua, cpu_index, stat_index) \ 58 ((cua)->cu_vals[CUA_INDEX((cua)->cu_nr_items, cpu_index, stat_index)]) 59 60 typedef struct { 61 uint64_t cu_nr_items; 62 char cu_pad[CUA_ALIGN - sizeof (uint64_t)]; 63 #ifdef __lint 64 volatile uint64_t cu_vals[1]; 65 #else 66 volatile uint64_t cu_vals[]; 67 #endif 68 } cpu_uarray_t __aligned(CUA_ALIGN); 69 70 extern cpu_uarray_t *cpu_uarray_zalloc(size_t, int); 71 extern void cpu_uarray_free(cpu_uarray_t *); 72 extern uint64_t cpu_uarray_sum(cpu_uarray_t *, size_t); 73 extern uint64_t cpu_uarray_sum_all(cpu_uarray_t *); 74 75 #endif /* _KERNEL */ 76 77 #ifdef __cplusplus 78 } 79 #endif 80 81 #endif /* _SYS_CPU_UARRAY_H */ 82