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authorMaciej S. Szmigiero <mail@maciej.szmigiero.name>2020-04-07 06:08:03 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-04-07 20:43:41 +0300
commitbb8b93b5b65130138d3c80f3136af721863f561a (patch)
treefe5bed9cc7a38155ff64f9db6ded6149f630678d /mm/Kconfig
parent4708f31885a0d3e41a03c39501df697e73406f6a (diff)
downloadlinux-bb8b93b5b65130138d3c80f3136af721863f561a.tar.xz
mm/zswap: allow setting default status, compressor and allocator in Kconfig
The compressed cache for swap pages (zswap) currently needs from 1 to 3 extra kernel command line parameters in order to make it work: it has to be enabled by adding a "zswap.enabled=1" command line parameter and if one wants a different compressor or pool allocator than the default lzo / zbud combination then these choices also need to be specified on the kernel command line in additional parameters. Using a different compressor and allocator for zswap is actually pretty common as guides often recommend using the lz4 / z3fold pair instead of the default one. In such case it is also necessary to remember to enable the appropriate compression algorithm and pool allocator in the kernel config manually. Let's avoid the need for adding these kernel command line parameters and automatically pull in the dependencies for the selected compressor algorithm and pool allocator by adding an appropriate default switches to Kconfig. The default values for these options match what the code was using previously as its defaults. Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vitaly Wool <vitaly.wool@konsulko.com> Link: http://lkml.kernel.org/r/20200202000112.456103-1-mail@maciej.szmigiero.name Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/Kconfig')
-rw-r--r--mm/Kconfig118
1 files changed, 117 insertions, 1 deletions
diff --git a/mm/Kconfig b/mm/Kconfig
index d286dc54458c..691021492e78 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -533,7 +533,6 @@ config MEM_SOFT_DIRTY
config ZSWAP
bool "Compressed cache for swap pages (EXPERIMENTAL)"
depends on FRONTSWAP && CRYPTO=y
- select CRYPTO_LZO
select ZPOOL
help
A lightweight compressed cache for swap pages. It takes
@@ -549,6 +548,123 @@ config ZSWAP
they have not be fully explored on the large set of potential
configurations and workloads that exist.
+choice
+ prompt "Compressed cache for swap pages default compressor"
+ depends on ZSWAP
+ default ZSWAP_COMPRESSOR_DEFAULT_LZO
+ help
+ Selects the default compression algorithm for the compressed cache
+ for swap pages.
+
+ For an overview what kind of performance can be expected from
+ a particular compression algorithm please refer to the benchmarks
+ available at the following LWN page:
+ https://lwn.net/Articles/751795/
+
+ If in doubt, select 'LZO'.
+
+ The selection made here can be overridden by using the kernel
+ command line 'zswap.compressor=' option.
+
+config ZSWAP_COMPRESSOR_DEFAULT_DEFLATE
+ bool "Deflate"
+ select CRYPTO_DEFLATE
+ help
+ Use the Deflate algorithm as the default compression algorithm.
+
+config ZSWAP_COMPRESSOR_DEFAULT_LZO
+ bool "LZO"
+ select CRYPTO_LZO
+ help
+ Use the LZO algorithm as the default compression algorithm.
+
+config ZSWAP_COMPRESSOR_DEFAULT_842
+ bool "842"
+ select CRYPTO_842
+ help
+ Use the 842 algorithm as the default compression algorithm.
+
+config ZSWAP_COMPRESSOR_DEFAULT_LZ4
+ bool "LZ4"
+ select CRYPTO_LZ4
+ help
+ Use the LZ4 algorithm as the default compression algorithm.
+
+config ZSWAP_COMPRESSOR_DEFAULT_LZ4HC
+ bool "LZ4HC"
+ select CRYPTO_LZ4HC
+ help
+ Use the LZ4HC algorithm as the default compression algorithm.
+
+config ZSWAP_COMPRESSOR_DEFAULT_ZSTD
+ bool "zstd"
+ select CRYPTO_ZSTD
+ help
+ Use the zstd algorithm as the default compression algorithm.
+endchoice
+
+config ZSWAP_COMPRESSOR_DEFAULT
+ string
+ depends on ZSWAP
+ default "deflate" if ZSWAP_COMPRESSOR_DEFAULT_DEFLATE
+ default "lzo" if ZSWAP_COMPRESSOR_DEFAULT_LZO
+ default "842" if ZSWAP_COMPRESSOR_DEFAULT_842
+ default "lz4" if ZSWAP_COMPRESSOR_DEFAULT_LZ4
+ default "lz4hc" if ZSWAP_COMPRESSOR_DEFAULT_LZ4HC
+ default "zstd" if ZSWAP_COMPRESSOR_DEFAULT_ZSTD
+ default ""
+
+choice
+ prompt "Compressed cache for swap pages default allocator"
+ depends on ZSWAP
+ default ZSWAP_ZPOOL_DEFAULT_ZBUD
+ help
+ Selects the default allocator for the compressed cache for
+ swap pages.
+ The default is 'zbud' for compatibility, however please do
+ read the description of each of the allocators below before
+ making a right choice.
+
+ The selection made here can be overridden by using the kernel
+ command line 'zswap.zpool=' option.
+
+config ZSWAP_ZPOOL_DEFAULT_ZBUD
+ bool "zbud"
+ select ZBUD
+ help
+ Use the zbud allocator as the default allocator.
+
+config ZSWAP_ZPOOL_DEFAULT_Z3FOLD
+ bool "z3fold"
+ select Z3FOLD
+ help
+ Use the z3fold allocator as the default allocator.
+
+config ZSWAP_ZPOOL_DEFAULT_ZSMALLOC
+ bool "zsmalloc"
+ select ZSMALLOC
+ help
+ Use the zsmalloc allocator as the default allocator.
+endchoice
+
+config ZSWAP_ZPOOL_DEFAULT
+ string
+ depends on ZSWAP
+ default "zbud" if ZSWAP_ZPOOL_DEFAULT_ZBUD
+ default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD
+ default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC
+ 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"
help