mm: Kconfig: simplify zswap configuration

- CONFIG_ZRAM: Zram is a user-facing feature, whereas zsmalloc is
  not. Don't make the user chase down a technical dependency like
  that, just select it in automatically when zram is requested. The
  CONFIG_CRYPTO dependency is redundant due to more specific deps.

- CONFIG_ZPOOL: This is not a user-facing feature. Hide the symbol and
  have it selected in as needed.

- CONFIG_ZSWAP: Select CRYPTO instead of depend. Common pattern.

- Make the ZSWAP suboptions and their descriptions (compression,
  allocation backend) a bit more straight-forward for the user.

Link: https://lkml.kernel.org/r/20220510152847.230957-5-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Johannes Weiner 2022-05-19 14:08:53 -07:00 коммит произвёл akpm
Родитель 519bcb7979
Коммит b3fbd58fcb
2 изменённых файлов: 27 добавлений и 31 удалений

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@ -1,8 +1,9 @@
# SPDX-License-Identifier: GPL-2.0 # SPDX-License-Identifier: GPL-2.0
config ZRAM config ZRAM
tristate "Compressed RAM block device support" tristate "Compressed RAM block device support"
depends on BLOCK && SYSFS && ZSMALLOC && CRYPTO depends on BLOCK && SYSFS
depends on CRYPTO_LZO || CRYPTO_ZSTD || CRYPTO_LZ4 || CRYPTO_LZ4HC || CRYPTO_842 depends on CRYPTO_LZO || CRYPTO_ZSTD || CRYPTO_LZ4 || CRYPTO_LZ4HC || CRYPTO_842
select ZSMALLOC
help help
Creates virtual block devices called /dev/zramX (X = 0, 1, ...). Creates virtual block devices called /dev/zramX (X = 0, 1, ...).
Pages written to these disks are compressed and stored in memory Pages written to these disks are compressed and stored in memory

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@ -9,6 +9,9 @@ menu "Memory Management options"
config ARCH_NO_SWAP config ARCH_NO_SWAP
bool bool
config ZPOOL
bool
menuconfig SWAP menuconfig SWAP
bool "Support for paging of anonymous memory (swap)" bool "Support for paging of anonymous memory (swap)"
depends on MMU && BLOCK && !ARCH_NO_SWAP depends on MMU && BLOCK && !ARCH_NO_SWAP
@ -21,8 +24,9 @@ menuconfig SWAP
config ZSWAP config ZSWAP
bool "Compressed cache for swap pages (EXPERIMENTAL)" bool "Compressed cache for swap pages (EXPERIMENTAL)"
depends on SWAP && CRYPTO=y depends on SWAP
select FRONTSWAP select FRONTSWAP
select CRYPTO
select ZPOOL select ZPOOL
help help
A lightweight compressed cache for swap pages. It takes A lightweight compressed cache for swap pages. It takes
@ -38,8 +42,18 @@ config ZSWAP
they have not be fully explored on the large set of potential they have not be fully explored on the large set of potential
configurations and workloads that exist. configurations and workloads that exist.
config ZSWAP_DEFAULT_ON
bool "Enable the compressed cache for swap pages by default"
depends on ZSWAP
help
If selected, the compressed cache for swap pages will be enabled
at boot, otherwise it will be disabled.
The selection made here can be overridden by using the kernel
command line 'zswap.enabled=' option.
choice choice
prompt "Compressed cache for swap pages default compressor" prompt "Default compressor"
depends on ZSWAP depends on ZSWAP
default ZSWAP_COMPRESSOR_DEFAULT_LZO default ZSWAP_COMPRESSOR_DEFAULT_LZO
help help
@ -105,7 +119,7 @@ config ZSWAP_COMPRESSOR_DEFAULT
default "" default ""
choice choice
prompt "Compressed cache for swap pages default allocator" prompt "Default allocator"
depends on ZSWAP depends on ZSWAP
default ZSWAP_ZPOOL_DEFAULT_ZBUD default ZSWAP_ZPOOL_DEFAULT_ZBUD
help help
@ -145,26 +159,9 @@ config ZSWAP_ZPOOL_DEFAULT
default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC
default "" default ""
config ZSWAP_DEFAULT_ON
bool "Enable the compressed cache for swap pages by default"
depends on ZSWAP
help
If selected, the compressed cache for swap pages will be enabled
at boot, otherwise it will be disabled.
The selection made here can be overridden by using the kernel
command line 'zswap.enabled=' option.
config ZPOOL
tristate "Common API for compressed memory storage"
depends on ZSWAP
help
Compressed memory storage API. This allows using either zbud or
zsmalloc.
config ZBUD config ZBUD
tristate "Low (Up to 2x) density storage for compressed pages" tristate "2:1 compression allocator (zbud)"
depends on ZPOOL depends on ZSWAP
help help
A special purpose allocator for storing compressed pages. A special purpose allocator for storing compressed pages.
It is designed to store up to two compressed pages per physical It is designed to store up to two compressed pages per physical
@ -173,8 +170,8 @@ config ZBUD
density approach when reclaim will be used. density approach when reclaim will be used.
config Z3FOLD config Z3FOLD
tristate "Up to 3x density storage for compressed pages" tristate "3:1 compression allocator (z3fold)"
depends on ZPOOL depends on ZSWAP
help help
A special purpose allocator for storing compressed pages. A special purpose allocator for storing compressed pages.
It is designed to store up to three compressed pages per physical It is designed to store up to three compressed pages per physical
@ -182,15 +179,13 @@ config Z3FOLD
still there. still there.
config ZSMALLOC config ZSMALLOC
tristate "Memory allocator for compressed pages" tristate
prompt "N:1 compression allocator (zsmalloc)" if ZSWAP
depends on MMU depends on MMU
help help
zsmalloc is a slab-based memory allocator designed to store zsmalloc is a slab-based memory allocator designed to store
compressed RAM pages. zsmalloc uses virtual memory mapping pages of various compression levels efficiently. It achieves
in order to reduce fragmentation. However, this results in a the highest storage density with the least amount of fragmentation.
non-standard allocator interface where a handle, not a pointer, is
returned by an alloc(). This handle must be mapped in order to
access the allocated space.
config ZSMALLOC_STAT config ZSMALLOC_STAT
bool "Export zsmalloc statistics" bool "Export zsmalloc statistics"