evictions: Limit the number of minor eviction surfaces to fit in RAM

We allocate more surfaces than used in a single pass in order to stress
the eviction code between batches. The intent here is not to exercise
swapping, and we fail to check that there is enough swap+memory to hold
all our surfaces. So limit the number of surfaces we allocate to fit
into RAM, and then require that the number of surfaces we need for
testing is less than the number of surfaces we can allocate.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/tests/eviction_common.c b/tests/eviction_common.c
index 91fb2df..d1c4798 100644 (file)
--- a/tests/eviction_common.c
+++ b/tests/eviction_common.c
@@ -64,6 +64,7 @@ static int minor_evictions(int fd, struct igt_eviction_test_ops *ops,
 {
        uint32_t *bo, *sel;
        int n, m, pass, fail;
+       int total_surfaces;
 
        /* Make sure nr_surfaces is not divisible by seven
         * to avoid duplicates in the selection loop below.
@@ -72,26 +73,26 @@ static int minor_evictions(int fd, struct igt_eviction_test_ops *ops,
        nr_surfaces *= 7;
        nr_surfaces += 3;
 
-       igt_require((uint64_t)nr_surfaces * surface_size / (1024 * 1024)
-                       < intel_get_total_ram_mb() * 9 / 10);
+       total_surfaces = (uint64_t)intel_get_total_ram_mb() * 9 /10 * 1024 *1024 / surface_size;
+       igt_require(nr_surfaces < total_surfaces);
 
-       bo = malloc(3*nr_surfaces*sizeof(*bo));
+       bo = malloc((nr_surfaces + total_surfaces)*sizeof(*bo));
        igt_assert(bo);
 
-       for (n = 0; n < 2*nr_surfaces; n++)
+       for (n = 0; n < total_surfaces; n++)
                bo[n] = ops->create(fd, surface_size);
 
        sel = bo + n;
        for (fail = 0, m = 0; fail < 10; fail++) {
                for (pass = 0; pass < 100; pass++) {
                        for (n = 0; n < nr_surfaces; n++, m += 7)
-                               sel[n] = bo[m%(2*nr_surfaces)];
+                               sel[n] = bo[m%total_surfaces];
                        ops->copy(fd, sel[0], sel[1], sel, nr_surfaces, 0);
                }
-               ops->copy(fd, bo[0], bo[0], bo, 2*nr_surfaces, ENOSPC);
+               ops->copy(fd, bo[0], bo[0], bo, total_surfaces, ENOSPC);
        }
 
-       for (n = 0; n < 2*nr_surfaces; n++)
+       for (n = 0; n < total_surfaces; n++)
                ops->close(fd, bo[n]);
        free(bo);