From 3fec6e5961b77af6a952b77f5c2ea26f7513b216 Mon Sep 17 00:00:00 2001 From: Nikhil V Date: Wed, 14 Feb 2024 13:09:32 +0530 Subject: [PATCH] PM: hibernate: Support to select compression algorithm Currently the default compression algorithm is selected based on compile time options. Introduce a module parameter "hibernate.compressor" to override this behaviour. Different compression algorithms have different characteristics and hibernation may benefit when it uses any of these algorithms, especially when a secondary algorithm(LZ4) offers better decompression speeds over a default algorithm(LZO), which in turn reduces hibernation image restore time. Users can override the default algorithm in two ways: 1) Passing "hibernate.compressor" as kernel command line parameter. Usage: LZO: hibernate.compressor=lzo LZ4: hibernate.compressor=lz4 2) Specifying the algorithm at runtime. Usage: LZO: echo lzo > /sys/module/hibernate/parameters/compressor LZ4: echo lz4 > /sys/module/hibernate/parameters/compressor Currently LZO and LZ4 are the supported algorithms. LZO is the default compression algorithm used with hibernation. Signed-off-by: Nikhil V Signed-off-by: Rafael J. Wysocki --- .../admin-guide/kernel-parameters.txt | 11 ++++ kernel/power/hibernate.c | 57 ++++++++++++++++++- 2 files changed, 65 insertions(+), 3 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 31b3a25680d0..8f7fb911b2cc 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1748,6 +1748,17 @@ (that will set all pages holding image data during restoration read-only). + hibernate.compressor= [HIBERNATION] Compression algorithm to be + used with hibernation. + Format: { lzo | lz4 } + Default: lzo + + lzo: Select LZO compression algorithm to + compress/decompress hibernation image. + + lz4: Select LZ4 compression algorithm to + compress/decompress hibernation image. + highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact size of . This works even on boxes that have no highmem otherwise. This also works to reduce highmem diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 219191d6d0e8..43b1a82e800c 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -47,7 +47,7 @@ dev_t swsusp_resume_device; sector_t swsusp_resume_block; __visible int in_suspend __nosavedata; -static const char *default_compressor = CONFIG_HIBERNATION_DEF_COMP; +static char hibernate_compressor[CRYPTO_MAX_ALG_NAME] = CONFIG_HIBERNATION_DEF_COMP; /* * Compression/decompression algorithm to be used while saving/loading @@ -748,7 +748,7 @@ int hibernate(void) * Query for the compression algorithm support if compression is enabled. */ if (!nocompress) { - strscpy(hib_comp_algo, default_compressor, sizeof(hib_comp_algo)); + strscpy(hib_comp_algo, hibernate_compressor, sizeof(hib_comp_algo)); if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) { pr_err("%s compression is not available\n", hib_comp_algo); return -EOPNOTSUPP; @@ -999,7 +999,7 @@ static int software_resume(void) if (swsusp_header_flags & SF_COMPRESSION_ALG_LZ4) strscpy(hib_comp_algo, COMPRESSION_ALGO_LZ4, sizeof(hib_comp_algo)); else - strscpy(hib_comp_algo, default_compressor, sizeof(hib_comp_algo)); + strscpy(hib_comp_algo, COMPRESSION_ALGO_LZO, sizeof(hib_comp_algo)); if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) { pr_err("%s compression is not available\n", hib_comp_algo); error = -EOPNOTSUPP; @@ -1422,6 +1422,57 @@ static int __init nohibernate_setup(char *str) return 1; } +static const char * const comp_alg_enabled[] = { +#if IS_ENABLED(CONFIG_CRYPTO_LZO) + COMPRESSION_ALGO_LZO, +#endif +#if IS_ENABLED(CONFIG_CRYPTO_LZ4) + COMPRESSION_ALGO_LZ4, +#endif +}; + +static int hibernate_compressor_param_set(const char *compressor, + const struct kernel_param *kp) +{ + unsigned int sleep_flags; + int index, ret; + + sleep_flags = lock_system_sleep(); + + index = sysfs_match_string(comp_alg_enabled, compressor); + if (index >= 0) { + ret = param_set_copystring(comp_alg_enabled[index], kp); + if (!ret) + strscpy(hib_comp_algo, comp_alg_enabled[index], + sizeof(hib_comp_algo)); + } else { + ret = index; + } + + unlock_system_sleep(sleep_flags); + + if (ret) + pr_debug("Cannot set specified compressor %s\n", + compressor); + + return ret; +} + +static const struct kernel_param_ops hibernate_compressor_param_ops = { + .set = hibernate_compressor_param_set, + .get = param_get_string, +}; + +static struct kparam_string hibernate_compressor_param_string = { + .maxlen = sizeof(hibernate_compressor), + .string = hibernate_compressor, +}; + +module_param_cb(compressor, &hibernate_compressor_param_ops, + &hibernate_compressor_param_string, 0644); +MODULE_PARM_DESC(compressor, + "Compression algorithm to be used with hibernation"); + __setup("noresume", noresume_setup); __setup("resume_offset=", resume_offset_setup); __setup("resume=", resume_setup);