Currently the default compression algorithm is selected based on
Kconfig. Introduce a kernel command line parameter "hib_compression" 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 offers better decompression speeds over a
default algorithm, which in turn reduces hibernation image restore time.
Users can set "hib_compression" command line parameter to override the
default algorithm. Currently LZO and LZ4 are the supported algorithms.
Usage:
LZO: hib_compression=lzo
LZ4: hib_compression=lz4
LZO is the default compression algorithm used with hibernation.
Signed-off-by: Nikhil V <quic_nprakash@xxxxxxxxxxx>
---
.../admin-guide/kernel-parameters.txt | 6 ++++
kernel/power/hibernate.c | 31 ++++++++++++++++++-
2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 31b3a25680d0..22255bd9a4e3 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1748,6 +1748,12 @@
(that will set all pages holding image data
during restoration read-only).
+ hib_compression= [COMPRESSION ALGORITHM]
+ lzo Select LZO compression algorithm to compress/decompress
+ hibernation images.
+ lz4 Select LZ4 compression algorithm to compress/decompress
+ hibernation images.
+
highmem=nn[KMG] [KNL,BOOT] forces the highmem zone to have an exact
size of <nn>. 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..75002fb3ad42 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -748,7 +748,8 @@ 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));
+ if (!hib_comp_algo[0])
+ 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;
@@ -1422,6 +1423,33 @@ 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 __init compression_setup(char *str)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(comp_alg_enabled); i++) {
+ if (!strcmp(str, comp_alg_enabled[i])) {
+ strscpy(hib_comp_algo, str, sizeof(hib_comp_algo));
+ goto setup_done;
+ }
+ }
+ pr_info("Cannot set specified compressor. Falling back to %s\n",
+ default_compressor);
+ strscpy(hib_comp_algo, default_compressor, sizeof(hib_comp_algo));
+
+setup_done:
+ return 1;
+}
+
__setup("noresume", noresume_setup);
__setup("resume_offset=", resume_offset_setup);
__setup("resume=", resume_setup);
@@ -1429,3 +1457,4 @@ __setup("hibernate=", hibernate_setup);
__setup("resumewait", resumewait_setup);
__setup("resumedelay=", resumedelay_setup);
__setup("nohibernate", nohibernate_setup);
+__setup("hib_compression=", compression_setup);
--
2.17.1
