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Diffstat (limited to 'src/bench.c')
| -rw-r--r-- | src/bench.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/src/bench.c b/src/bench.c new file mode 100644 index 0000000..4b1e3be --- /dev/null +++ b/src/bench.c @@ -0,0 +1,183 @@ +/* ========================================================================== + Licensed under BSD 2clause license. See LICENSE file for more information + Author: Michał Łyszczek <michal.lyszczek@bofc.pl> + ========================================================================== */ + + +/* ==== Include files ======================================================= */ + + +#include "bench.h" + +#include <assert.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> + +#include "opts.h" +#include "utils.h" + + +/* ==== Private macros ==================================================== */ + + +#define BENCH_START() \ + for (j = 0; j <= loops; ++j) \ + { \ + /* + * this tries to flush cpu cache - provided that user set + * opts.cache_size big enough + */ \ + \ + if (opts.cache_size) \ + { \ + memcpy(f1, f2, opts.cache_size); \ + } \ + ts(start) + +#define BENCH_END() \ + ts(finish); \ + ts_add_diff(taken, start, finish); \ +} + +/* ==== Private functions =================================================== */ + + +/* ========================================================================== + prints benchmark report to standard output + ========================================================================== */ + + +static void bench_report +( + void* taken, /* time taken on data copying */ + float copied /* number of bytes copied */ +) +{ + struct jedec jd_bps; /* bytes per second in jedec format */ + struct jedec jd_copied; /* number of bytes copied in jedec format */ + unsigned long us; /* time taken copying data in microseconds */ + float bps; /* bytes per second rate */ + /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/ + + if ((us = ts2us(taken)) == 0) + { + us = 1; + } + + bps = copied / us; + bps *= 1000000; + + bytes2jedec(bps, &jd_bps); + bytes2jedec(copied, &jd_copied); + + printf("copied %5lu %cB, in %5lu us, rate %5lu %cB/s\n", + jd_copied.val, + jd_copied.pre, + us, + jd_bps.val, + jd_bps.pre); +} + + +/* ==== Public functions ==================================================== */ + + +/* ========================================================================== + performs benchmark on pointers dst and src. dst and src can be heap or + stack allocated. + ========================================================================== */ + + +int bench +( + void *dst, /* destination pointer */ + void *src, /* source pointer */ + void *f1, /* first pointer used to flush cpu cache */ + void *f2 /* second pointer used to flush cpu cache */ +) +{ + void *start; /* timer indicating benchmark start */ + void *finish; /* timer indicating benchmark finish */ + void *taken; /* timer for time taken on benchmark */ + float bytes_copied; /* bytes copied in * iteration */ + size_t loops; /* loops needed to copy requested bytes */ + size_t i; /* iterator for loop */ + size_t j; /* iterator for loop */ + size_t k; /* iterator for loop */ + struct jedec jd_block_size; /* block size in jedec format */ + struct jedec jd_report_intvl; /* report interval value in jedec format */ + /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/ + + start = ts_new(); + finish = ts_new(); + taken = ts_new(); + + srand(time(NULL)); + loops = opts.report_intvl / opts.block_size; + bytes2jedec(opts.block_size, &jd_block_size); + bytes2jedec(opts.report_intvl, &jd_report_intvl); + + printf("block size: %lu %cB, report every %lu %cB, iterations %lu\n", + jd_block_size.val, + jd_block_size.pre, + jd_report_intvl.val, + jd_report_intvl.pre, + opts.num_intvl); + + /* + * for systems that uses optimistic memory allocation (like linux) dst + * and src may not really allocated just yet. dst and src will be + * allocated when we first access them. This causes first memory copy + * iteration to take much longer time causing program to show wrong + * transfer rate. To prevent this behaviour we do a simple memory copy + * here, so dst + */ + + memcpy(dst, src, opts.block_size); + + for (i = 0, j = 0; i != opts.num_intvl; ++i) + { + ts_reset(taken); + + switch (opts.method) + { + case METHOD_MEMCPY: + BENCH_START(); + memcpy(dst, src, opts.block_size); + BENCH_END(); + break; + + case METHOD_BBB: + BENCH_START(); + + for (k = 0; k != opts.block_size; ++k) + { + unsigned char *d; /* source pointer */ + unsigned char *s; /* destination pointer */ + /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/ + + d = dst; + s = src; + + d[k] = s[k]; + } + + BENCH_END(); + break; + + default: + assert(0 && "test method not supported, should not get here"); + } + + bytes_copied = (float)j * opts.block_size; + bench_report(taken, bytes_copied); + } + + free(start); + free(finish); + free(taken); + + return 0; +} |