diff --git a/regressions/ck_epoch/validate/Makefile b/regressions/ck_epoch/validate/Makefile
index a0c1165..446c008 100644
--- a/regressions/ck_epoch/validate/Makefile
+++ b/regressions/ck_epoch/validate/Makefile
@@ -1,7 +1,7 @@
 .PHONY: check clean distribution
 
 OBJECTS=ck_stack ck_epoch_synchronize ck_epoch_poll ck_epoch_call \
-	ck_epoch_section ck_epoch_section_2
+	ck_epoch_section ck_epoch_section_2 torture
 HALF=`expr $(CORES) / 2`
 
 all: $(OBJECTS)
@@ -12,6 +12,7 @@ check: all
 	./ck_epoch_poll $(CORES) 1 1
 	./ck_epoch_section
 	./ck_epoch_section_2 $(HALF) $(HALF) 1
+	./torture $(HALF) $(HALF) 1
 
 ck_epoch_synchronize: ck_epoch_synchronize.c ../../../include/ck_stack.h ../../../include/ck_epoch.h ../../../src/ck_epoch.c
 	$(CC) $(CFLAGS) -o ck_epoch_synchronize ck_epoch_synchronize.c ../../../src/ck_epoch.c
@@ -19,6 +20,9 @@ ck_epoch_synchronize: ck_epoch_synchronize.c ../../../include/ck_stack.h ../../.
 ck_epoch_poll: ck_epoch_poll.c ../../../include/ck_stack.h ../../../include/ck_epoch.h ../../../src/ck_epoch.c
 	$(CC) $(CFLAGS) -o ck_epoch_poll ck_epoch_poll.c ../../../src/ck_epoch.c
 
+torture: torture.c ../../../include/ck_epoch.h ../../../src/ck_epoch.c
+	$(CC) $(CFLAGS) -o torture torture.c ../../../src/ck_epoch.c
+
 ck_epoch_section: ck_epoch_section.c ../../../include/ck_epoch.h ../../../src/ck_epoch.c
 	$(CC) $(CFLAGS) -o ck_epoch_section ck_epoch_section.c ../../../src/ck_epoch.c
 
diff --git a/regressions/ck_epoch/validate/torture.c b/regressions/ck_epoch/validate/torture.c
new file mode 100644
index 0000000..84d6f87
--- /dev/null
+++ b/regressions/ck_epoch/validate/torture.c
@@ -0,0 +1,228 @@
+/*
+ * Copyright 2010-2015 Samy Al Bahra.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <assert.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <ck_cc.h>
+#include <ck_pr.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <string.h>
+#include <ck_epoch.h>
+#include <ck_stack.h>
+
+#include "../../common.h"
+
+static unsigned int n_rd;
+static unsigned int n_wr;
+static unsigned int n_threads;
+static unsigned int barrier;
+static unsigned int leave;
+static unsigned int first;
+
+struct {
+	unsigned int value;
+} valid CK_CC_CACHELINE = { 1 };
+
+struct {
+	unsigned int value;
+} invalid CK_CC_CACHELINE;
+
+#ifndef PAIRS_S
+#define PAIRS_S 10000
+#endif
+
+#ifndef CK_EPOCH_T_DEPTH
+#define CK_EPOCH_T_DEPTH	8
+#endif
+
+static ck_epoch_t epoch;
+static struct affinity a;
+
+static void
+test(struct ck_epoch_record *record)
+{
+	unsigned int j[3];
+	unsigned int b, c;
+	const unsigned int r = 100;
+	size_t i;
+
+	for (i = 0; i < 8; i++) {
+		ck_epoch_begin(record, NULL);
+		c = ck_pr_load_uint(&invalid.value);
+		ck_pr_fence_load();
+		b = ck_pr_load_uint(&valid.value);
+		ck_test(c > b, "Invalid value: %u > %u\n", c, b);
+		ck_epoch_end(record, NULL);
+	}
+
+	ck_epoch_begin(record, NULL);
+
+	/* This implies no early load of epoch occurs. */
+	j[0] = record->epoch;
+
+
+	/* We should observe up to one epoch migration. */
+	do {
+		ck_pr_fence_load();
+		j[1] = ck_pr_load_uint(&epoch.epoch);
+
+		if (ck_pr_load_uint(&leave) == 1) {
+			ck_epoch_end(record, NULL);
+			return;
+		}
+	} while (j[1] == j[0]);
+
+	/* No more epoch migrations should occur */
+	for (i = 0; i < r; i++) {
+		ck_pr_fence_strict_load();
+		j[2] = ck_pr_load_uint(&epoch.epoch);
+
+		ck_test(j[2] != j[1], "Inconsistency detected: %u %u %u\n",
+		    j[0], j[1], j[2]);
+	}
+
+	ck_epoch_end(record, NULL);
+	return;
+}
+
+static void *
+read_thread(void *unused CK_CC_UNUSED)
+{
+	ck_epoch_record_t record CK_CC_CACHELINE;
+
+	ck_epoch_register(&epoch, &record);
+
+	if (aff_iterate(&a)) {
+		perror("ERROR: failed to affine thread");
+		exit(EXIT_FAILURE);
+	}
+
+	ck_pr_inc_uint(&barrier);
+	while (ck_pr_load_uint(&barrier) < n_threads);
+
+	do {
+		test(&record);
+		test(&record);
+		test(&record);
+		test(&record);
+	} while (ck_pr_load_uint(&leave) == 0);
+
+	ck_pr_dec_uint(&n_rd);
+
+	return NULL;
+}
+
+static void *
+write_thread(void *unused CK_CC_UNUSED)
+{
+	ck_epoch_record_t record;
+	unsigned long iterations = 0;
+	unsigned int i = 1;
+	bool c = ck_pr_faa_uint(&first, 1);
+
+	ck_epoch_register(&epoch, &record);
+
+	if (aff_iterate(&a)) {
+		perror("ERROR: failed to affine thread");
+		exit(EXIT_FAILURE);
+	}
+
+	ck_pr_inc_uint(&barrier);
+	while (ck_pr_load_uint(&barrier) < n_threads);
+
+	do {
+		/*
+		 * A thread should never observe invalid.value > valid.value.
+		 * inside a protected section. Only
+		 * invalid.value <= valid.value is valid.
+		 */
+		if (!c) ck_pr_store_uint(&valid.value, i);
+		ck_epoch_synchronize(&record);
+		if (!c) ck_pr_store_uint(&invalid.value, i++);
+
+		if (!c) ck_pr_store_uint(&valid.value, i);
+		ck_epoch_synchronize(&record);
+		if (!c) ck_pr_store_uint(&invalid.value, i++);
+
+		if (!c) ck_pr_store_uint(&valid.value, i);
+		ck_epoch_synchronize(&record);
+		if (!c) ck_pr_store_uint(&invalid.value, i++);
+
+		if (!c) ck_pr_store_uint(&valid.value, i);
+		ck_epoch_synchronize(&record);
+		if (!c) ck_pr_store_uint(&invalid.value, i++);
+
+		if (!c) ck_pr_store_uint(&valid.value, i);
+		ck_epoch_synchronize(&record);
+		if (!c) ck_pr_store_uint(&invalid.value, i++);
+
+		iterations += 4;
+	} while (ck_pr_load_uint(&leave) == 0 &&
+		 ck_pr_load_uint(&n_rd) > 0);
+
+	fprintf(stderr, "%lu iterations\n", iterations);
+	return NULL;
+}
+
+int
+main(int argc, char *argv[])
+{
+	unsigned int i;
+	pthread_t *threads;
+
+	if (argc != 4) {
+		ck_error("Usage: stack <#readers> <#writers> <affinity delta>\n");
+	}
+
+	n_rd = atoi(argv[1]);
+	n_wr = atoi(argv[2]);
+	n_threads = n_wr + n_rd;
+
+	a.delta = atoi(argv[3]);
+	a.request = 0;
+
+	threads = malloc(sizeof(pthread_t) * n_threads);
+	ck_epoch_init(&epoch);
+
+	for (i = 0; i < n_rd; i++)
+		pthread_create(threads + i, NULL, read_thread, NULL);
+
+	do {
+		pthread_create(threads + i, NULL, write_thread, NULL);
+	} while (++i < n_wr + n_rd);
+
+	common_sleep(30);
+	ck_pr_store_uint(&leave, 1);
+
+	for (i = 0; i < n_threads; i++)
+		pthread_join(threads[i], NULL);
+
+	return 0;
+}