Allow zram to merge identical pages into signle one:
echo 1 > /sys/block/zramX/merge
Signed-off-by: Alexey Romanov <avromanov@xxxxxxxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 716c2f72805e..1dae3564cabd 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1197,6 +1197,30 @@ static ssize_t compact_store(struct device *dev,
return len;
}
+static int zram_do_scan(struct zram *zram);
+
+static ssize_t merge_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t len)
+{
+ struct zram *zram = dev_to_zram(dev);
+ int ret;
+
+ down_read(&zram->init_lock);
+ if (!init_done(zram)) {
+ up_read(&zram->init_lock);
+ return -EINVAL;
+ }
+
+ ret = zram_do_scan(zram);
+ if (ret != 0) {
+ up_read(&zram->init_lock);
+ return -ENOMEM;
+ }
+
+ up_read(&zram->init_lock);
+ return len;
+}
+
static ssize_t io_stat_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -2569,6 +2593,7 @@ static const struct block_device_operations zram_devops = {
};
static DEVICE_ATTR_WO(compact);
+static DEVICE_ATTR_WO(merge);
static DEVICE_ATTR_RW(disksize);
static DEVICE_ATTR_RO(initstate);
static DEVICE_ATTR_WO(reset);
@@ -2609,6 +2634,7 @@ static struct attribute *zram_disk_attrs[] = {
#ifdef CONFIG_ZRAM_WRITEBACK
&dev_attr_bd_stat.attr,
#endif
+ &dev_attr_merge.attr,
&dev_attr_debug_stat.attr,
#ifdef CONFIG_ZRAM_MULTI_COMP
&dev_attr_recomp_algorithm.attr,
--
2.25.1
