Remove `strict_min_purge_interval` option

Option `experimental_hpa_strict_min_purge_interval` was expected to be
temporary to simplify rollout of a bugfix. Now, when bugfix rollout is
complete it is safe to remove this option.

include/jemalloc/internal/hpa_opts.h

@@ -50,14 +50,6 @@ struct hpa_shard_opts_s {
 	 */
 	uint64_t min_purge_interval_ms;
 
-	/*
-	 * Strictly respect minimum amout of time between purges.
-	 *
-	 * This is an option to provide backward compatibility for staged rollout of
-	 * purging logic fix.
-	 */
-	bool experimental_strict_min_purge_interval;
-
 	/*
 	 * Maximum number of hugepages to purge on each purging attempt.
 	 */
@@ -83,8 +75,6 @@ struct hpa_shard_opts_s {
 	10 * 1000,							\
 	/* min_purge_interval_ms */					\
 	5 * 1000,							\
-	/* experimental_strict_min_purge_interval */			\
-	false,								\
 	/* experimental_max_purge_nhp */				\
 	-1								\
 }

src/ctl.c

@@ -103,7 +103,6 @@ CTL_PROTO(opt_hpa_slab_max_alloc)
 CTL_PROTO(opt_hpa_hugification_threshold)
 CTL_PROTO(opt_hpa_hugify_delay_ms)
 CTL_PROTO(opt_hpa_min_purge_interval_ms)
-CTL_PROTO(opt_experimental_hpa_strict_min_purge_interval)
 CTL_PROTO(opt_experimental_hpa_max_purge_nhp)
 CTL_PROTO(opt_hpa_dirty_mult)
 CTL_PROTO(opt_hpa_sec_nshards)
@@ -462,8 +461,6 @@ static const ctl_named_node_t opt_node[] = {
 		CTL(opt_hpa_hugification_threshold)},
 	{NAME("hpa_hugify_delay_ms"), CTL(opt_hpa_hugify_delay_ms)},
 	{NAME("hpa_min_purge_interval_ms"), CTL(opt_hpa_min_purge_interval_ms)},
-	{NAME("experimental_hpa_strict_min_purge_interval"),
-		CTL(opt_experimental_hpa_strict_min_purge_interval)},
 	{NAME("experimental_hpa_max_purge_nhp"),
 		CTL(opt_experimental_hpa_max_purge_nhp)},
 	{NAME("hpa_dirty_mult"), CTL(opt_hpa_dirty_mult)},
@@ -2202,8 +2199,6 @@ CTL_RO_NL_GEN(opt_hpa_hugification_threshold,
 CTL_RO_NL_GEN(opt_hpa_hugify_delay_ms, opt_hpa_opts.hugify_delay_ms, uint64_t)
 CTL_RO_NL_GEN(opt_hpa_min_purge_interval_ms, opt_hpa_opts.min_purge_interval_ms,
     uint64_t)
-CTL_RO_NL_GEN(opt_experimental_hpa_strict_min_purge_interval,
-    opt_hpa_opts.experimental_strict_min_purge_interval, bool)
 CTL_RO_NL_GEN(opt_experimental_hpa_max_purge_nhp,
     opt_hpa_opts.experimental_max_purge_nhp, ssize_t)
 

src/hpa.c

@@ -512,14 +512,9 @@ hpa_try_hugify(tsdn_t *tsdn, hpa_shard_t *shard) {
 static bool
 hpa_min_purge_interval_passed(tsdn_t *tsdn, hpa_shard_t *shard) {
 	malloc_mutex_assert_owner(tsdn, &shard->mtx);
-	if (shard->opts.experimental_strict_min_purge_interval) {
-		uint64_t since_last_purge_ms = shard->central->hooks.ms_since(
-		    &shard->last_purge);
-		if (since_last_purge_ms < shard->opts.min_purge_interval_ms) {
-		     return false;
-		}
-	}
-	return true;
+	uint64_t since_last_purge_ms = shard->central->hooks.ms_since(
+	    &shard->last_purge);
+	return since_last_purge_ms >= shard->opts.min_purge_interval_ms;
 }
 
 /*

src/jemalloc.c

@@ -1571,10 +1571,6 @@ malloc_conf_init_helper(sc_data_t *sc_data, unsigned bin_shard_sizes[SC_NBINS],
 			    "hpa_min_purge_interval_ms", 0, 0,
 			    CONF_DONT_CHECK_MIN, CONF_DONT_CHECK_MAX, false);
 
-			CONF_HANDLE_BOOL(
-			    opt_hpa_opts.experimental_strict_min_purge_interval,
-			    "experimental_hpa_strict_min_purge_interval");
-
 			CONF_HANDLE_SSIZE_T(
 			    opt_hpa_opts.experimental_max_purge_nhp,
 			    "experimental_hpa_max_purge_nhp", -1, SSIZE_MAX);

src/stats.c

@@ -1564,7 +1564,6 @@ stats_general_print(emitter_t *emitter) {
 	OPT_WRITE_SIZE_T("hpa_hugification_threshold")
 	OPT_WRITE_UINT64("hpa_hugify_delay_ms")
 	OPT_WRITE_UINT64("hpa_min_purge_interval_ms")
-	OPT_WRITE_BOOL("experimental_hpa_strict_min_purge_interval")
 	OPT_WRITE_SSIZE_T("experimental_hpa_max_purge_nhp")
 	if (je_mallctl("opt.hpa_dirty_mult", (void *)&u32v, &u32sz, NULL, 0)
 	    == 0) {

test/unit/hpa.c

@@ -34,8 +34,6 @@ static hpa_shard_opts_t test_hpa_shard_opts_default = {
 	10 * 1000,
 	/* min_purge_interval_ms */
 	5 * 1000,
-	/* experimental_strict_min_purge_interval */
-	false,
 	/* experimental_max_purge_nhp */
 	-1
 };
@@ -53,8 +51,6 @@ static hpa_shard_opts_t test_hpa_shard_opts_purge = {
 	0,
 	/* min_purge_interval_ms */
 	5 * 1000,
-	/* experimental_strict_min_purge_interval */
-	false,
 	/* experimental_max_purge_nhp */
 	-1
 };
@@ -506,7 +502,7 @@ TEST_BEGIN(test_purge_no_infinite_loop) {
 }
 TEST_END
 
-TEST_BEGIN(test_no_experimental_strict_min_purge_interval) {
+TEST_BEGIN(test_no_min_purge_interval) {
 	test_skip_if(!hpa_supported());
 
 	hpa_hooks_t hooks;
@@ -520,6 +516,7 @@ TEST_BEGIN(test_no_experimental_strict_min_purge_interval) {
 
 	hpa_shard_opts_t opts = test_hpa_shard_opts_default;
 	opts.deferral_allowed = true;
+	opts.min_purge_interval_ms = 0;
 
 	hpa_shard_t *shard = create_test_data(&hooks, &opts);
 
@@ -547,7 +544,7 @@ TEST_BEGIN(test_no_experimental_strict_min_purge_interval) {
 }
 TEST_END
 
-TEST_BEGIN(test_experimental_strict_min_purge_interval) {
+TEST_BEGIN(test_min_purge_interval) {
 	test_skip_if(!hpa_supported());
 
 	hpa_hooks_t hooks;
@@ -561,7 +558,6 @@ TEST_BEGIN(test_experimental_strict_min_purge_interval) {
 
 	hpa_shard_opts_t opts = test_hpa_shard_opts_default;
 	opts.deferral_allowed = true;
-	opts.experimental_strict_min_purge_interval = true;
 
 	hpa_shard_t *shard = create_test_data(&hooks, &opts);
 
@@ -631,6 +627,7 @@ TEST_BEGIN(test_purge) {
 		pai_dalloc(tsdn, &shard->pai, edatas[i],
 		    &deferred_work_generated);
 	}
+	nstime_init2(&defer_curtime, 6, 0);
 	hpa_shard_do_deferred_work(tsdn, shard);
 
 	expect_zu_eq(0, ndefer_hugify_calls, "Hugified too early");
@@ -642,9 +639,15 @@ TEST_BEGIN(test_purge) {
 	expect_zu_eq(2, ndefer_purge_calls, "Expect purges");
 	ndefer_purge_calls = 0;
 
+	nstime_init2(&defer_curtime, 12, 0);
 	hpa_shard_do_deferred_work(tsdn, shard);
 
-	expect_zu_eq(0, ndefer_hugify_calls, "Hugified too early");
+	/*
+	 * We are still having 5 active hugepages and now they are
+	 * matching hugification criteria long enough to actually hugify them.
+	 */
+	expect_zu_eq(5, ndefer_hugify_calls, "Expect hugification");
+	ndefer_hugify_calls = 0;
 	expect_zu_eq(0, ndefer_dehugify_calls, "Dehugified too early");
 	/*
 	 * We still have completely dirty hugepage, but we are below
@@ -691,6 +694,7 @@ TEST_BEGIN(test_experimental_max_purge_nhp) {
 		pai_dalloc(tsdn, &shard->pai, edatas[i],
 		    &deferred_work_generated);
 	}
+	nstime_init2(&defer_curtime, 6, 0);
 	hpa_shard_do_deferred_work(tsdn, shard);
 
 	expect_zu_eq(0, ndefer_hugify_calls, "Hugified too early");
@@ -702,14 +706,17 @@ TEST_BEGIN(test_experimental_max_purge_nhp) {
 	expect_zu_eq(1, ndefer_purge_calls, "Expect purges");
 	ndefer_purge_calls = 0;
 
+	nstime_init2(&defer_curtime, 12, 0);
 	hpa_shard_do_deferred_work(tsdn, shard);
 
-	expect_zu_eq(0, ndefer_hugify_calls, "Hugified too early");
+	expect_zu_eq(5, ndefer_hugify_calls, "Expect hugification");
+	ndefer_hugify_calls = 0;
 	expect_zu_eq(0, ndefer_dehugify_calls, "Dehugified too early");
 	/* We still above the limit for dirty pages. */
 	expect_zu_eq(1, ndefer_purge_calls, "Expect purge");
 	ndefer_purge_calls = 0;
 
+	nstime_init2(&defer_curtime, 18, 0);
 	hpa_shard_do_deferred_work(tsdn, shard);
 
 	expect_zu_eq(0, ndefer_hugify_calls, "Hugified too early");
@@ -741,8 +748,8 @@ main(void) {
 	    test_alloc_dalloc_batch,
 	    test_defer_time,
 	    test_purge_no_infinite_loop,
-	    test_no_experimental_strict_min_purge_interval,
-	    test_experimental_strict_min_purge_interval,
+	    test_no_min_purge_interval,
+	    test_min_purge_interval,
 	    test_purge,
 	    test_experimental_max_purge_nhp);
 }

test/unit/mallctl.c

@@ -292,8 +292,6 @@ TEST_BEGIN(test_mallctl_opt) {
 	TEST_MALLCTL_OPT(size_t, hpa_sec_max_bytes, always);
 	TEST_MALLCTL_OPT(size_t, hpa_sec_bytes_after_flush, always);
 	TEST_MALLCTL_OPT(size_t, hpa_sec_batch_fill_extra, always);
-	TEST_MALLCTL_OPT(bool, experimental_hpa_strict_min_purge_interval,
-	    always);
 	TEST_MALLCTL_OPT(ssize_t, experimental_hpa_max_purge_nhp, always);
 	TEST_MALLCTL_OPT(unsigned, narenas, always);
 	TEST_MALLCTL_OPT(const char *, percpu_arena, always);