# SPDX-License-Identifier: GPL-2.0 config ZRAM tristate "Compressed RAM block device support" depends on BLOCK && SYSFS && ZSMALLOC && CRYPTO select CRYPTO_LZO default n help Creates virtual block devices called /dev/zramX (X = 0, 1, ...). Pages written to these disks are compressed and stored in memory itself. These disks allow very fast I/O and compression provides good amounts of memory savings. It has several use cases, for example: /tmp storage, use as swap disks and maybe many more. See zram.txt for more information. config ZRAM_WRITEBACK bool "Write back incompressible page to backing device" depends on ZRAM default n help With incompressible page, there is no memory saving to keep it in memory. Instead, write it out to backing device. For this feature, admin should set up backing device via /sys/block/zramX/backing_dev. See zram.txt for more infomration.