1 files changed, 238 insertions, 0 deletions

diff --git a/bin/armsinglepage.c b/bin/armsinglepage.c
new file mode 100644
index 0000000..cf619b7
--- /dev/null
+++ b/bin/armsinglepage.c
@@ -0,0 +1,238 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+#include <inttypes.h>
+
+#include "asm/cacheparams.h"
+
+#include <litmus/rt_param.h>
+
+#include "perfcounters.h"
+
+#include "color.h"
+#include "litmus.h"
+
+#define CPU             1
+#define NR_LOOPS        10000
+
+static int pages_per_datum;
+/* Number of pages in a "data" element, each with same color. */
+
+static int nr_data;
+/* Number of "data" elements. */
+
+
+struct page;
+#define NR_PAGE_INTS    ((PAGE_SIZE - CACHE_LINE_SIZE) / sizeof(uint32_t))
+struct page {
+        struct page *ptr;
+        struct page *_unused[CACHE_LINE_SIZE / sizeof(struct page*) - 1];
+        uint32_t ints[NR_PAGE_INTS];
+};
+
+struct datum {
+        struct page *pages;
+};
+
+/*
+ * Get a random number in [0, max). Not really a good way to do this.
+ */
+static int randrange(const int max)
+{
+        return (rand() / (RAND_MAX / max + 1));
+}
+
+static void setup_page_ints(struct page *page)
+{
+        int i;
+        
+        for (i = 0; i < NR_PAGE_INTS; i++) {
+                page->ints[i] = randrange(RAND_MAX);
+        }
+}
+
+/*
+ * Sattolo's algorithm makes a random cycle that includes all the elements
+ * in the items array.
+ */
+static void sattolo(int *items, const int len)
+{
+        int i;
+        /* first set up 0, 1, ..., n - 1 */
+        for (i = 0; i < len; i++)
+                items[i] = i;
+        /* note: i is now n */
+        while (1 < i--) {
+                /* 0 <= j < i */
+                int t, j = randrange(i);
+                t = items[i];
+                items[i] = items[j];
+                items[j] = t;
+        }
+}
+
+static uint32_t get_sum(struct page *page)
+{
+        uint32_t sum = 0;
+        int i;
+
+        for (i = 0; i < NR_PAGE_INTS; i += CACHE_LINE_SIZE / sizeof(uint32_t)) {
+                sum += page->ints[i];
+        } 
+        return sum;
+}
+
+static uint32_t do_read(struct page* page)
+{
+        struct page *old;
+        uint32_t sum = 0;
+
+        do {
+                old = page;
+                page = page->ptr;
+                sum += get_sum(old);
+        } while (page);
+        return sum;
+}
+
+#define MULT    699050667
+#define SHIFT   24
+
+static inline int64_t clocksource_cyc2ns(cycles_t cycles, uint32_t mult, uint32_t shift)
+{                                                    
+        return ((uint64_t) cycles * mult) >> shift;
+}
+
+#if 0
+static void print_difference(const cycles_t start, const cycles_t end)
+{
+        cycles_t diff = end - start;
+
+        printf("difference: %10llu = %10llu ns\n", diff, clocksource_cyc2ns(diff, MULT, SHIFT));
+}
+#endif
+
+#define quit_on_err(err, msg) do { \
+        if (err) { \
+                fprintf(stderr, "error: " msg); \
+                goto out; \
+        } \
+} while (0)
+
+int main(int argc, char **argv)
+{
+        struct color_ctrl_page *color_ctrl;
+        struct datum *data;
+        int *read_order;
+        int i, j, err = 0;
+        cycles_t start, end;
+        uint32_t sum = 0;
+        int64_t nanoseconds;
+        double avg_nanoseconds;
+
+        quit_on_err(PAGE_SIZE != sizeof(struct page),
+                        "PAGE_SIZE != sizeof(struct page)\n");
+
+        if (3 > argc) {
+                fprintf(stderr, "%s: [pages-per-datum] [nr-data]\n", argv[0]);
+                err = 1;
+                goto out;
+        }
+
+        pages_per_datum = atoi(argv[1]);
+        nr_data = atoi(argv[2]);
+
+        quit_on_err(0 == nr_data || 0 == pages_per_datum, "zero argument\n");
+        quit_on_err(16 < nr_data, "too many nr_data\n");
+
+        read_order = malloc(pages_per_datum * sizeof(*read_order));
+        data = malloc(nr_data * sizeof(*data));
+        quit_on_err(!read_order || !data, "malloc\n");
+
+        err = be_migrate_to(CPU);
+        quit_on_err(err, "migrate to cpu\n");
+
+        color_ctrl = get_color_ctrl();
+        if (!color_ctrl) {
+                fprintf(stderr, "could not map color ctrl\n");
+                err = -1;
+                goto out;
+        }
+
+        /* Always allocating this many pages of the same color. */
+        color_ctrl->pages[0] = pages_per_datum;
+
+        for (i = 0; i < nr_data; i++) {
+                const unsigned nr_bytes = sizeof(data[i].pages[0]) * pages_per_datum;
+
+                /* give each datum its own color (XXX no checks to ensure not >
+                 * NR_COLORS!) */
+
+                color_ctrl->colors[0] = i;
+                fprintf(stderr, "color_mallocing %u bytes\n", nr_bytes);
+                data[i].pages = color_malloc(nr_bytes);
+                if (!data[i].pages) {
+                        fprintf(stderr, "could not color malloc\n");
+                        err = -1;
+                        goto out;
+                }
+        }
+
+        sattolo(read_order, pages_per_datum);
+
+        for (i = 0; i < nr_data; i++) {
+                for (j = 0; j < pages_per_datum; j++) {
+                        if (0 != read_order[j]) {
+                                /* not the last element */
+                                data[i].pages[j].ptr = &(data[i].pages[read_order[j]]);
+                        } else {
+                                /* last element in pages inside of datum walk */
+                                if (nr_data - 1 == i) {
+                                        /* last element globally */
+                                        data[i].pages[j].ptr = NULL;
+                                } else {
+                                        /* jump to next datum */
+                                        data[i].pages[j].ptr = &(data[i + 1].pages[0]);
+                                }
+                        }
+
+                        setup_page_ints(&(data[i].pages[j]));
+                }
+        }
+
+#if 0
+        null_call(&start);
+        null_call(&end);
+        print_difference(start, end);
+
+        null_call(&start);
+        sum += do_read(data[0].pages);
+        null_call(&end);
+        print_difference(start, end);
+
+        null_call(&start);
+        sum += do_read(data[0].pages);
+        null_call(&end);
+        print_difference(start, end);
+
+        null_call(&start);
+        sum += do_read(data[0].pages);
+        null_call(&end);
+        print_difference(start, end);
+#endif
+
+        null_call(&start);
+        for (i = 0; i < NR_LOOPS; i++) {
+                sum += do_read(data[0].pages);
+        }
+        null_call(&end);
+        nanoseconds = clocksource_cyc2ns(end - start, MULT, SHIFT);
+        avg_nanoseconds = ((double)nanoseconds) / NR_LOOPS;
+        printf("%3d, %10.3f, %10.3f\n", nr_data, avg_nanoseconds,
+                        avg_nanoseconds / (nr_data * pages_per_datum));
+
+out:
+        return err;
+}