perf bench mem: Remove repetition around time measurement

We have two copies of each mem benchmark: one using cycles to
measure time, the second for gettimeofday().

Unify.

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/bench/mem-functions.c b/tools/perf/bench/mem-functions.c
index 19d45c377ac184300814cc34ffaa76f5fb504ef9..8599ed96ee1f608cffd588d4375788ae65c10eae 100644 (file)
--- a/tools/perf/bench/mem-functions.c
+++ b/tools/perf/bench/mem-functions.c
@@ -51,6 +51,11 @@ static const struct option options[] = {
        OPT_END()
 };
 
+union bench_clock {
+       u64             cycles;
+       struct timeval  tv;
+};
+
 typedef void *(*memcpy_t)(void *, const void *, size_t);
 typedef void *(*memset_t)(void *, int, size_t);
 
@@ -91,6 +96,26 @@ static u64 get_cycles(void)
        return clk;
 }
 
+static void clock_get(union bench_clock *t)
+{
+       if (use_cycles)
+               t->cycles = get_cycles();
+       else
+               BUG_ON(gettimeofday(&t->tv, NULL));
+}
+
+static union bench_clock clock_diff(union bench_clock *s, union bench_clock *e)
+{
+       union bench_clock t;
+
+       if (use_cycles)
+               t.cycles = e->cycles - s->cycles;
+       else
+               timersub(&e->tv, &s->tv, &t.tv);
+
+       return t;
+}
+
 static double timeval2double(struct timeval *ts)
 {
        return (double)ts->tv_sec + (double)ts->tv_usec / (double)USEC_PER_SEC;
@@ -109,8 +134,7 @@ static double timeval2double(struct timeval *ts)
 
 struct bench_mem_info {
        const struct function *functions;
-       u64 (*do_cycles)(const struct function *r, size_t size, void *src, void *dst);
-       double (*do_gettimeofday)(const struct function *r, size_t size, void *src, void *dst);
+       union bench_clock (*do_op)(const struct function *r, size_t size, void *src, void *dst);
        const char *const *usage;
        bool alloc_src;
 };
@@ -119,7 +143,7 @@ static void __bench_mem_function(struct bench_mem_info *info, int r_idx, size_t
 {
        const struct function *r = &info->functions[r_idx];
        double result_bps = 0.0;
-       u64 result_cycles = 0;
+       union bench_clock rt = { 0 };
        void *src = NULL, *dst = zalloc(size);
 
        printf("# function '%s' (%s)\n", r->name, r->desc);
@@ -136,25 +160,23 @@ static void __bench_mem_function(struct bench_mem_info *info, int r_idx, size_t
        if (bench_format == BENCH_FORMAT_DEFAULT)
                printf("# Copying %s bytes ...\n\n", size_str);
 
-       if (use_cycles) {
-               result_cycles = info->do_cycles(r, size, src, dst);
-       } else {
-               result_bps = info->do_gettimeofday(r, size, src, dst);
-       }
+       rt = info->do_op(r, size, src, dst);
 
        switch (bench_format) {
        case BENCH_FORMAT_DEFAULT:
                if (use_cycles) {
-                       printf(" %14lf cycles/byte\n", (double)result_cycles/size_total);
+                       printf(" %14lf cycles/byte\n", (double)rt.cycles/size_total);
                } else {
+                       result_bps = size_total/timeval2double(&rt.tv);
                        print_bps(result_bps);
                }
                break;
 
        case BENCH_FORMAT_SIMPLE:
                if (use_cycles) {
-                       printf("%lf\n", (double)result_cycles/size_total);
+                       printf("%lf\n", (double)rt.cycles/size_total);
                } else {
+                       result_bps = size_total/timeval2double(&rt.tv);
                        printf("%lf\n", result_bps);
                }
                break;
@@ -235,38 +257,21 @@ static void memcpy_prefault(memcpy_t fn, size_t size, void *src, void *dst)
        fn(dst, src, size);
 }
 
-static u64 do_memcpy_cycles(const struct function *r, size_t size, void *src, void *dst)
-{
-       u64 cycle_start = 0ULL, cycle_end = 0ULL;
-       memcpy_t fn = r->fn.memcpy;
-       int i;
-
-       memcpy_prefault(fn, size, src, dst);
-
-       cycle_start = get_cycles();
-       for (i = 0; i < nr_loops; ++i)
-               fn(dst, src, size);
-       cycle_end = get_cycles();
-
-       return cycle_end - cycle_start;
-}
-
-static double do_memcpy_gettimeofday(const struct function *r, size_t size, void *src, void *dst)
+static union bench_clock do_memcpy(const struct function *r, size_t size,
+                                  void *src, void *dst)
 {
-       struct timeval tv_start, tv_end, tv_diff;
+       union bench_clock start, end;
        memcpy_t fn = r->fn.memcpy;
        int i;
 
        memcpy_prefault(fn, size, src, dst);
 
-       BUG_ON(gettimeofday(&tv_start, NULL));
+       clock_get(&start);
        for (i = 0; i < nr_loops; ++i)
                fn(dst, src, size);
-       BUG_ON(gettimeofday(&tv_end, NULL));
+       clock_get(&end);
 
-       timersub(&tv_end, &tv_start, &tv_diff);
-
-       return (double)(((double)size * nr_loops) / timeval2double(&tv_diff));
+       return clock_diff(&start, &end);
 }
 
 struct function memcpy_functions[] = {
@@ -292,8 +297,7 @@ int bench_mem_memcpy(int argc, const char **argv)
 {
        struct bench_mem_info info = {
                .functions              = memcpy_functions,
-               .do_cycles              = do_memcpy_cycles,
-               .do_gettimeofday        = do_memcpy_gettimeofday,
+               .do_op                  = do_memcpy,
                .usage                  = bench_mem_memcpy_usage,
                .alloc_src              = true,
        };
@@ -301,29 +305,10 @@ int bench_mem_memcpy(int argc, const char **argv)
        return bench_mem_common(argc, argv, &info);
 }
 
-static u64 do_memset_cycles(const struct function *r, size_t size, void *src __maybe_unused, void *dst)
-{
-       u64 cycle_start = 0ULL, cycle_end = 0ULL;
-       memset_t fn = r->fn.memset;
-       int i;
-
-       /*
-        * We prefault the freshly allocated memory range here,
-        * to not measure page fault overhead:
-        */
-       fn(dst, -1, size);
-
-       cycle_start = get_cycles();
-       for (i = 0; i < nr_loops; ++i)
-               fn(dst, i, size);
-       cycle_end = get_cycles();
-
-       return cycle_end - cycle_start;
-}
-
-static double do_memset_gettimeofday(const struct function *r, size_t size, void *src __maybe_unused, void *dst)
+static union bench_clock do_memset(const struct function *r, size_t size,
+                                  void *src __maybe_unused, void *dst)
 {
-       struct timeval tv_start, tv_end, tv_diff;
+       union bench_clock start, end;
        memset_t fn = r->fn.memset;
        int i;
 
@@ -333,14 +318,12 @@ static double do_memset_gettimeofday(const struct function *r, size_t size, void
         */
        fn(dst, -1, size);
 
-       BUG_ON(gettimeofday(&tv_start, NULL));
+       clock_get(&start);
        for (i = 0; i < nr_loops; ++i)
                fn(dst, i, size);
-       BUG_ON(gettimeofday(&tv_end, NULL));
-
-       timersub(&tv_end, &tv_start, &tv_diff);
+       clock_get(&end);
 
-       return (double)(((double)size * nr_loops) / timeval2double(&tv_diff));
+       return clock_diff(&start, &end);
 }
 
 static const char * const bench_mem_memset_usage[] = {
@@ -366,8 +349,7 @@ int bench_mem_memset(int argc, const char **argv)
 {
        struct bench_mem_info info = {
                .functions              = memset_functions,
-               .do_cycles              = do_memset_cycles,
-               .do_gettimeofday        = do_memset_gettimeofday,
+               .do_op                  = do_memset,
                .usage                  = bench_mem_memset_usage,
        };