2 files changed, 55 insertions, 3 deletions

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 4457d0395bfb..180613b478a6 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -281,6 +281,47 @@ static ssize_t mem_used_max_store(struct device *dev,
 	return len;
 }
 
+static ssize_t idle_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct zram *zram = dev_to_zram(dev);
+	unsigned long nr_pages = zram->disksize >> PAGE_SHIFT;
+	int index;
+	char mode_buf[8];
+	ssize_t sz;
+
+	sz = strscpy(mode_buf, buf, sizeof(mode_buf));
+	if (sz <= 0)
+		return -EINVAL;
+
+	/* ignore trailing new line */
+	if (mode_buf[sz - 1] == '\n')
+		mode_buf[sz - 1] = 0x00;
+
+	if (strcmp(mode_buf, "all"))
+		return -EINVAL;
+
+	down_read(&zram->init_lock);
+	if (!init_done(zram)) {
+		up_read(&zram->init_lock);
+		return -EINVAL;
+	}
+
+	for (index = 0; index < nr_pages; index++) {
+		zram_slot_lock(zram, index);
+		if (!zram_allocated(zram, index))
+			goto next;
+
+		zram_set_flag(zram, index, ZRAM_IDLE);
+next:
+		zram_slot_unlock(zram, index);
+	}
+
+	up_read(&zram->init_lock);
+
+	return len;
+}
+
 #ifdef CONFIG_ZRAM_WRITEBACK
 static void reset_bdev(struct zram *zram)
 {
@@ -638,6 +679,7 @@ static void zram_debugfs_destroy(void)
 
 static void zram_accessed(struct zram *zram, u32 index)
 {
+	zram_clear_flag(zram, index, ZRAM_IDLE);
 	zram->table[index].ac_time = ktime_get_boottime();
 }
 
@@ -670,12 +712,13 @@ static ssize_t read_block_state(struct file *file, char __user *buf,
 
 		ts = ktime_to_timespec64(zram->table[index].ac_time);
 		copied = snprintf(kbuf + written, count,
-			"%12zd %12lld.%06lu %c%c%c\n",
+			"%12zd %12lld.%06lu %c%c%c%c\n",
 			index, (s64)ts.tv_sec,
 			ts.tv_nsec / NSEC_PER_USEC,
 			zram_test_flag(zram, index, ZRAM_SAME) ? 's' : '.',
 			zram_test_flag(zram, index, ZRAM_WB) ? 'w' : '.',
-			zram_test_flag(zram, index, ZRAM_HUGE) ? 'h' : '.');
+			zram_test_flag(zram, index, ZRAM_HUGE) ? 'h' : '.',
+			zram_test_flag(zram, index, ZRAM_IDLE) ? 'i' : '.');
 
 		if (count < copied) {
 			zram_slot_unlock(zram, index);
@@ -720,7 +763,10 @@ static void zram_debugfs_unregister(struct zram *zram)
 #else
 static void zram_debugfs_create(void) {};
 static void zram_debugfs_destroy(void) {};
-static void zram_accessed(struct zram *zram, u32 index) {};
+static void zram_accessed(struct zram *zram, u32 index)
+{
+	zram_clear_flag(zram, index, ZRAM_IDLE);
+};
 static void zram_debugfs_register(struct zram *zram) {};
 static void zram_debugfs_unregister(struct zram *zram) {};
 #endif
@@ -924,6 +970,9 @@ static void zram_free_page(struct zram *zram, size_t index)
 #ifdef CONFIG_ZRAM_MEMORY_TRACKING
 	zram->table[index].ac_time = 0;
 #endif
+	if (zram_test_flag(zram, index, ZRAM_IDLE))
+		zram_clear_flag(zram, index, ZRAM_IDLE);
+
 	if (zram_test_flag(zram, index, ZRAM_HUGE)) {
 		zram_clear_flag(zram, index, ZRAM_HUGE);
 		atomic64_dec(&zram->stats.huge_pages);
@@ -1589,6 +1638,7 @@ static DEVICE_ATTR_RO(initstate);
 static DEVICE_ATTR_WO(reset);
 static DEVICE_ATTR_WO(mem_limit);
 static DEVICE_ATTR_WO(mem_used_max);
+static DEVICE_ATTR_WO(idle);
 static DEVICE_ATTR_RW(max_comp_streams);
 static DEVICE_ATTR_RW(comp_algorithm);
 #ifdef CONFIG_ZRAM_WRITEBACK
@@ -1602,6 +1652,7 @@ static struct attribute *zram_disk_attrs[] = {
 	&dev_attr_compact.attr,
 	&dev_attr_mem_limit.attr,
 	&dev_attr_mem_used_max.attr,
+	&dev_attr_idle.attr,
 	&dev_attr_max_comp_streams.attr,
 	&dev_attr_comp_algorithm.attr,
 #ifdef CONFIG_ZRAM_WRITEBACK
diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
index 4f83f1f14b0a..a84611b97867 100644
--- a/drivers/block/zram/zram_drv.h
+++ b/drivers/block/zram/zram_drv.h
@@ -48,6 +48,7 @@ enum zram_pageflags {
 	ZRAM_SAME,	/* Page consists the same element */
 	ZRAM_WB,	/* page is stored on backing_device */
 	ZRAM_HUGE,	/* Incompressible page */
+	ZRAM_IDLE,	/* not accessed page since last idle marking */
 
 	__NR_ZRAM_PAGEFLAGS,
 };