[PATCH 3/3] test: slab_arena -- Verify madvise
Cyrill Gorcunov
gorcunov at gmail.com
Wed May 1 18:50:06 MSK 2019
Since madvise support depends on sys libraries
and kernel version we print error if only small
supports it and /proc/self/smaps provide more
less decent VmFlags.
Part of #3509
---
https://github.com/tarantool/tarantool/issues/3509
test/slab_arena.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 90 insertions(+)
diff --git a/test/slab_arena.c b/test/slab_arena.c
index d0a78d1..5c5085c 100644
--- a/test/slab_arena.c
+++ b/test/slab_arena.c
@@ -3,6 +3,7 @@
#include <stdio.h>
#include <limits.h>
#include <stdlib.h>
+#include <string.h>
#include <time.h>
#include "unit.h"
@@ -15,6 +16,93 @@ slab_arena_print(struct slab_arena *arena)
arena->used, arena->slab_size);
}
+#define is_hex_digit(c) \
+ (((c) >= '0' && (c) <= '9') || \
+ ((c) >= 'a' && (c) <= 'f') || \
+ ((c) >= 'A' && (c) <= 'F'))
+
+static int is_vma_range_fmt(char *line, unsigned long *start, unsigned long *end)
+{
+ char *p = line;
+ while (*line && is_hex_digit(*line))
+ line++;
+
+ if (*line++ != '-')
+ return 0;
+
+ while (*line && is_hex_digit(*line))
+ line++;
+
+ if (*line++ != ' ')
+ return 0;
+
+ sscanf(p, "%lx-%lx", start, end);
+ return 1;
+}
+
+static void
+slab_test_madvise(void)
+{
+ struct slab_arena arena;
+ struct quota quota;
+ FILE *f = NULL;
+ void *ptr;
+
+ quota_init("a, 2000000);
+ slab_arena_create(&arena, "a, 3000000, 1, MAP_PRIVATE);
+
+ /*
+ * Will fetch from preallocated area.
+ */
+ ptr = slab_map(&arena);
+ if (!ptr) {
+ printf("can't obtain slab\n");
+ goto out;
+ }
+
+ /*
+ * If system supports madvise call, we should try
+ * fetch the precise VMA state from smaps file,
+ * but if only it exists.
+ */
+ if (!slab_arena_madvise_dontdump(&arena)) {
+ unsigned long start = 0, end = 0;
+ char buf[1024], *tok = NULL;
+ bool found = false;
+
+ f = fopen("/proc/self/smaps", "r");
+ if (!f)
+ goto out;
+
+ while (fgets(buf, sizeof(buf), f)) {
+ is_vma_range_fmt(buf, &start, &end);
+ if (strncmp(buf, "VmFlags: ", 9) || (void *)start != ptr)
+ continue;
+ tok = buf;
+ break;
+ }
+
+ if (tok) {
+ for (tok = strtok(tok, " \n"); tok;
+ tok = strtok(NULL, " \n")) {
+ if (strcmp(tok, "dd"))
+ continue;
+ found = true;
+ break;
+ }
+ }
+
+ if (!found)
+ printf("ERROR: Expected dd flag on VMA address %p\n", ptr);
+
+ fclose(f);
+ }
+
+out:
+ slab_unmap(&arena, ptr);
+ slab_arena_destroy(&arena);
+}
+
int main()
{
struct quota quota;
@@ -42,4 +130,6 @@ int main()
slab_arena_create(&arena, "a, 3000000, 1, MAP_PRIVATE);
slab_arena_print(&arena);
slab_arena_destroy(&arena);
+
+ slab_test_madvise();
}
--
2.20.1
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