1# SPDX-License-Identifier: GPL-2.0 2config ZRAM 3 tristate "Compressed RAM block device support" 4 depends on BLOCK && SYSFS && ZSMALLOC && CRYPTO 5 select CRYPTO_LZO 6 default n 7 help 8 Creates virtual block devices called /dev/zramX (X = 0, 1, ...). 9 Pages written to these disks are compressed and stored in memory 10 itself. These disks allow very fast I/O and compression provides 11 good amounts of memory savings. 12 13 It has several use cases, for example: /tmp storage, use as swap 14 disks and maybe many more. 15 16 See Documentation/blockdev/zram.txt for more information. 17 18config ZRAM_WRITEBACK 19 bool "Write back incompressible page to backing device" 20 depends on ZRAM 21 default n 22 help 23 With incompressible page, there is no memory saving to keep it 24 in memory. Instead, write it out to backing device. 25 For this feature, admin should set up backing device via 26 /sys/block/zramX/backing_dev. 27 28 See Documentation/blockdev/zram.txt for more information. 29 30config ZRAM_MEMORY_TRACKING 31 bool "Track zRam block status" 32 depends on ZRAM && DEBUG_FS 33 help 34 With this feature, admin can track the state of allocated blocks 35 of zRAM. Admin could see the information via 36 /sys/kernel/debug/zram/zramX/block_state. 37 38 See Documentation/blockdev/zram.txt for more information. 39