From a06c6f5d3cc90b3b070d7b99979d57238db77a86 Mon Sep 17 00:00:00 2001 From: Nikhil V Date: Mon, 22 Jan 2024 18:45:26 +0530 Subject: PM: hibernate: Move to crypto APIs for LZO compression Currently for hibernation, LZO is the only compression algorithm available and uses the existing LZO library calls. However, there is no flexibility to switch to other algorithms which provides better results. The main idea is that different compression algorithms have different characteristics and hibernation may benefit when it uses alternate algorithms. By moving to crypto based APIs, it lays a foundation to use other compression algorithms for hibernation. There are no functional changes introduced by this approach. Signed-off-by: Nikhil V Signed-off-by: Rafael J. Wysocki --- kernel/power/hibernate.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'kernel/power/hibernate.c') diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 4b0b7cf2e019..76b7ff619c90 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -47,6 +47,15 @@ dev_t swsusp_resume_device; sector_t swsusp_resume_block; __visible int in_suspend __nosavedata; +static const char *default_compressor = CONFIG_HIBERNATION_DEF_COMP; + +/* + * Compression/decompression algorithm to be used while saving/loading + * image to/from disk. This would later be used in 'kernel/power/swap.c' + * to allocate comp streams. + */ +char hib_comp_algo[CRYPTO_MAX_ALG_NAME]; + enum { HIBERNATION_INVALID, HIBERNATION_PLATFORM, @@ -732,6 +741,17 @@ int hibernate(void) return -EPERM; } + /* + * Query for the compression algorithm support if compression is enabled. + */ + if (!nocompress) { + strscpy(hib_comp_algo, default_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; + } + } + sleep_flags = lock_system_sleep(); /* The snapshot device should not be opened while we're running */ if (!hibernate_acquire()) { @@ -955,6 +975,19 @@ static int software_resume(void) if (error) goto Unlock; + /* + * Check if the hibernation image is compressed. If so, query for + * the algorithm support. + */ + if (!(swsusp_header_flags & SF_NOCOMPRESS_MODE)) { + strscpy(hib_comp_algo, default_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); + error = -EOPNOTSUPP; + goto Unlock; + } + } + /* The snapshot device should not be opened while we're running */ if (!hibernate_acquire()) { error = -EBUSY; -- cgit v1.2.3 From 8bc29736357e7f9a6bd0d16b57b5612197e1924b Mon Sep 17 00:00:00 2001 From: Nikhil V Date: Mon, 22 Jan 2024 18:45:27 +0530 Subject: PM: hibernate: Add support for LZ4 compression for hibernation Extend the support for LZ4 compression to be used with hibernation. The main idea is that different compression algorithms have different characteristics and hibernation may benefit when it uses any of these algorithms: a default algorithm, having higher compression rate but is slower(compression/decompression) and a secondary algorithm, that is faster(compression/decompression) but has lower compression rate. LZ4 algorithm has better decompression speeds over LZO. This reduces the hibernation image restore time. As per test results: LZO LZ4 Size before Compression(bytes) 682696704 682393600 Size after Compression(bytes) 146502402 155993547 Decompression Rate 335.02 MB/s 501.05 MB/s Restore time 4.4s 3.8s LZO is the default compression algorithm used for hibernation. Enable CONFIG_HIBERNATION_COMP_LZ4 to set the default compressor as LZ4. Signed-off-by: Nikhil V Signed-off-by: Rafael J. Wysocki --- kernel/power/Kconfig | 5 +++++ kernel/power/hibernate.c | 25 ++++++++++++++++++++++--- kernel/power/power.h | 14 ++++++++++++++ 3 files changed, 41 insertions(+), 3 deletions(-) (limited to 'kernel/power/hibernate.c') diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index d4167159bae8..afce8130d8b9 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -101,11 +101,16 @@ config HIBERNATION_COMP_LZO bool "lzo" depends on CRYPTO_LZO +config HIBERNATION_COMP_LZ4 + bool "lz4" + depends on CRYPTO_LZ4 + endchoice config HIBERNATION_DEF_COMP string default "lzo" if HIBERNATION_COMP_LZO + default "lz4" if HIBERNATION_COMP_LZ4 help Default compressor to be used for hibernation. diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 76b7ff619c90..219191d6d0e8 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -727,6 +727,9 @@ static int load_image_and_restore(void) return error; } +#define COMPRESSION_ALGO_LZO "lzo" +#define COMPRESSION_ALGO_LZ4 "lz4" + /** * hibernate - Carry out system hibernation, including saving the image. */ @@ -786,11 +789,24 @@ int hibernate(void) if (hibernation_mode == HIBERNATION_PLATFORM) flags |= SF_PLATFORM_MODE; - if (nocompress) + if (nocompress) { flags |= SF_NOCOMPRESS_MODE; - else + } else { flags |= SF_CRC32_MODE; + /* + * By default, LZO compression is enabled. Use SF_COMPRESSION_ALG_LZ4 + * to override this behaviour and use LZ4. + * + * Refer kernel/power/power.h for more details + */ + + if (!strcmp(hib_comp_algo, COMPRESSION_ALGO_LZ4)) + flags |= SF_COMPRESSION_ALG_LZ4; + else + flags |= SF_COMPRESSION_ALG_LZO; + } + pm_pr_dbg("Writing hibernation image.\n"); error = swsusp_write(flags); swsusp_free(); @@ -980,7 +996,10 @@ static int software_resume(void) * the algorithm support. */ if (!(swsusp_header_flags & SF_NOCOMPRESS_MODE)) { - strscpy(hib_comp_algo, default_compressor, sizeof(hib_comp_algo)); + 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)); if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) { pr_err("%s compression is not available\n", hib_comp_algo); error = -EOPNOTSUPP; diff --git a/kernel/power/power.h b/kernel/power/power.h index 5efa2c987057..518349272848 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -167,11 +167,25 @@ extern int swsusp_swap_in_use(void); * Flags that can be passed from the hibernatig hernel to the "boot" kernel in * the image header. */ +#define SF_COMPRESSION_ALG_LZO 0 /* dummy, details given below */ #define SF_PLATFORM_MODE 1 #define SF_NOCOMPRESS_MODE 2 #define SF_CRC32_MODE 4 #define SF_HW_SIG 8 +/* + * Bit to indicate the compression algorithm to be used(for LZ4). The same + * could be checked while saving/loading image to/from disk to use the + * corresponding algorithms. + * + * By default, LZO compression is enabled if SF_CRC32_MODE is set. Use + * SF_COMPRESSION_ALG_LZ4 to override this behaviour and use LZ4. + * + * SF_CRC32_MODE, SF_COMPRESSION_ALG_LZO(dummy) -> Compression, LZO + * SF_CRC32_MODE, SF_COMPRESSION_ALG_LZ4 -> Compression, LZ4 + */ +#define SF_COMPRESSION_ALG_LZ4 16 + /* kernel/power/hibernate.c */ int swsusp_check(bool exclusive); extern void swsusp_free(void); -- cgit v1.2.3 From 3fec6e5961b77af6a952b77f5c2ea26f7513b216 Mon Sep 17 00:00:00 2001 From: Nikhil V Date: Wed, 14 Feb 2024 13:09:32 +0530 Subject: 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 --- Documentation/admin-guide/kernel-parameters.txt | 11 +++++ kernel/power/hibernate.c | 57 +++++++++++++++++++++++-- 2 files changed, 65 insertions(+), 3 deletions(-) (limited to 'kernel/power/hibernate.c') 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); -- cgit v1.2.3