projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| b2441318 | 1 | # SPDX-License-Identifier: GPL-2.0 |
| 16a4bfb9 NG |
2 | config ZRAM |
| 3 | tristate "Compressed RAM block device support" | |
| ebaf9ab5 | 4 | depends on BLOCK && SYSFS && ZSMALLOC && CRYPTO |
| 3d711a38 | 5 | depends on CRYPTO_LZO || CRYPTO_ZSTD || CRYPTO_LZ4 || CRYPTO_LZ4HC || CRYPTO_842 |
| 16a4bfb9 NG |
6 | help |
| 7 | Creates virtual block devices called /dev/zramX (X = 0, 1, ...). | |
| 8 | Pages written to these disks are compressed and stored in memory | |
| 9 | itself. These disks allow very fast I/O and compression provides | |
| 10 | good amounts of memory savings. | |
| 11 | ||
| 12 | It has several use cases, for example: /tmp storage, use as swap | |
| 13 | disks and maybe many more. | |
| 14 | ||
| e7751617 | 15 | See Documentation/admin-guide/blockdev/zram.rst for more information. |
| 5a47074f | 16 | |
| 3d711a38 RS |
17 | choice |
| 18 | prompt "Default zram compressor" | |
| 19 | default ZRAM_DEF_COMP_LZORLE | |
| 20 | depends on ZRAM | |
| 21 | ||
| 22 | config ZRAM_DEF_COMP_LZORLE | |
| 23 | bool "lzo-rle" | |
| 24 | depends on CRYPTO_LZO | |
| 25 | ||
| 26 | config ZRAM_DEF_COMP_ZSTD | |
| 27 | bool "zstd" | |
| 28 | depends on CRYPTO_ZSTD | |
| 29 | ||
| 30 | config ZRAM_DEF_COMP_LZ4 | |
| 31 | bool "lz4" | |
| 32 | depends on CRYPTO_LZ4 | |
| 33 | ||
| 34 | config ZRAM_DEF_COMP_LZO | |
| 35 | bool "lzo" | |
| 36 | depends on CRYPTO_LZO | |
| 37 | ||
| 38 | config ZRAM_DEF_COMP_LZ4HC | |
| 39 | bool "lz4hc" | |
| 40 | depends on CRYPTO_LZ4HC | |
| 41 | ||
| 42 | config ZRAM_DEF_COMP_842 | |
| 43 | bool "842" | |
| 44 | depends on CRYPTO_842 | |
| 45 | ||
| 46 | endchoice | |
| 47 | ||
| 48 | config ZRAM_DEF_COMP | |
| 49 | string | |
| 50 | default "lzo-rle" if ZRAM_DEF_COMP_LZORLE | |
| 51 | default "zstd" if ZRAM_DEF_COMP_ZSTD | |
| 52 | default "lz4" if ZRAM_DEF_COMP_LZ4 | |
| 53 | default "lzo" if ZRAM_DEF_COMP_LZO | |
| 54 | default "lz4hc" if ZRAM_DEF_COMP_LZ4HC | |
| 55 | default "842" if ZRAM_DEF_COMP_842 | |
| 56 | ||
| 5a47074f | 57 | config ZRAM_WRITEBACK |
| a939888e | 58 | bool "Write back incompressible or idle page to backing device" |
| 5a47074f | 59 | depends on ZRAM |
| 5a47074f MK |
60 | help |
| 61 | With incompressible page, there is no memory saving to keep it | |
| 62 | in memory. Instead, write it out to backing device. | |
| 63 | For this feature, admin should set up backing device via | |
| 64 | /sys/block/zramX/backing_dev. | |
| 65 | ||
| a939888e MK |
66 | With /sys/block/zramX/{idle,writeback}, application could ask |
| 67 | idle page's writeback to the backing device to save in memory. | |
| 68 | ||
| e7751617 | 69 | See Documentation/admin-guide/blockdev/zram.rst for more information. |
| c0265342 MK |
70 | |
| 71 | config ZRAM_MEMORY_TRACKING | |
| 72 | bool "Track zRam block status" | |
| 73 | depends on ZRAM && DEBUG_FS | |
| 74 | help | |
| 75 | With this feature, admin can track the state of allocated blocks | |
| 76 | of zRAM. Admin could see the information via | |
| 77 | /sys/kernel/debug/zram/zramX/block_state. | |
| 78 | ||
| e7751617 | 79 | See Documentation/admin-guide/blockdev/zram.rst for more information. |