Add arena.i.retain_grow_limit

This option controls the max size when grow_retained.  This is useful when we
have customized extent hooks reserving physical memory (e.g. 1G huge pages).
Without this feature, the default increasing sequence could result in fragmented
and wasted physical memory.

1 files changed, 49 insertions, 0 deletions

diff --git a/test/unit/mallctl.c b/test/unit/mallctl.c
index 5612cce..94f801e 100644
--- a/test/unit/mallctl.c
+++ b/test/unit/mallctl.c
@@ -556,6 +556,54 @@ TEST_BEGIN(test_arena_i_dss) {
 }
 TEST_END
 
+TEST_BEGIN(test_arena_i_retain_grow_limit) {
+	size_t old_limit, new_limit, default_limit;
+	size_t mib[3];
+	size_t miblen;
+
+	bool retain_enabled;
+	size_t sz = sizeof(retain_enabled);
+	assert_d_eq(mallctl("opt.retain", &retain_enabled, &sz, NULL, 0),
+	    0, "Unexpected mallctl() failure");
+	test_skip_if(!retain_enabled);
+
+	sz = sizeof(default_limit);
+	miblen = sizeof(mib)/sizeof(size_t);
+	assert_d_eq(mallctlnametomib("arena.0.retain_grow_limit", mib, &miblen),
+	    0, "Unexpected mallctlnametomib() error");
+
+	assert_d_eq(mallctlbymib(mib, miblen, &default_limit, &sz, NULL, 0), 0,
+	    "Unexpected mallctl() failure");
+	assert_zu_eq(default_limit, sz_pind2sz(EXTENT_GROW_MAX_PIND),
+	    "Unexpected default for retain_grow_limit");
+
+	new_limit = PAGE - 1;
+	assert_d_eq(mallctlbymib(mib, miblen, NULL, NULL, &new_limit,
+	    sizeof(new_limit)), EFAULT, "Unexpected mallctl() success");
+
+	new_limit = PAGE + 1;
+	assert_d_eq(mallctlbymib(mib, miblen, NULL, NULL, &new_limit,
+	    sizeof(new_limit)), 0, "Unexpected mallctl() failure");
+	assert_d_eq(mallctlbymib(mib, miblen, &old_limit, &sz, NULL, 0), 0,
+	    "Unexpected mallctl() failure");
+	assert_zu_eq(old_limit, PAGE,
+	    "Unexpected value for retain_grow_limit");
+
+	/* Expect grow less than psize class 10. */
+	new_limit = sz_pind2sz(10) - 1;
+	assert_d_eq(mallctlbymib(mib, miblen, NULL, NULL, &new_limit,
+	    sizeof(new_limit)), 0, "Unexpected mallctl() failure");
+	assert_d_eq(mallctlbymib(mib, miblen, &old_limit, &sz, NULL, 0), 0,
+	    "Unexpected mallctl() failure");
+	assert_zu_eq(old_limit, sz_pind2sz(9),
+	    "Unexpected value for retain_grow_limit");
+
+	/* Restore to default. */
+	assert_d_eq(mallctlbymib(mib, miblen, NULL, NULL, &default_limit,
+	    sizeof(default_limit)), 0, "Unexpected mallctl() failure");
+}
+TEST_END
+
 TEST_BEGIN(test_arenas_dirty_decay_ms) {
 	ssize_t dirty_decay_ms, orig_dirty_decay_ms, prev_dirty_decay_ms;
 	size_t sz = sizeof(ssize_t);
@@ -727,6 +775,7 @@ main(void) {
 	    test_arena_i_purge,
 	    test_arena_i_decay,
 	    test_arena_i_dss,
+	    test_arena_i_retain_grow_limit,
 	    test_arenas_dirty_decay_ms,
 	    test_arenas_muzzy_decay_ms,
 	    test_arenas_constants,