# SPDX-License-Identifier: GPL-2.0 config [31mCONFIG_ZRAM[0m tristate "Compressed RAM block device support" depends on [31mCONFIG_BLOCK[0m && [31mCONFIG_SYSFS[0m && [31mCONFIG_ZSMALLOC[0m && [31mCONFIG_CRYPTO[0m select [31mCONFIG_CRYPTO_LZO[0m 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 Documentation/admin-guide/blockdev/zram.rst for more information. config [31mCONFIG_ZRAM_WRITEBACK[0m bool "Write back incompressible or idle page to backing device" depends on [31mCONFIG_ZRAM[0m 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. With /sys/block/zramX/{idle,writeback}, application could ask idle page's writeback to the backing device to save in memory. See Documentation/admin-guide/blockdev/zram.rst for more information. config [31mCONFIG_ZRAM_MEMORY_TRACKING[0m bool "Track zRam block status" depends on [31mCONFIG_ZRAM[0m && [31mCONFIG_DEBUG_FS[0m help With this feature, admin can track the state of allocated blocks of zRAM. Admin could see the information via /sys/kernel/debug/zram/zramX/block_state. See Documentation/admin-guide/blockdev/zram.rst for more information. |