This patch series covers the following:
1. Renaming lzo* to generic names, except for lzo_xxx() APIs. This is
used in the next patch where we move to crypto based APIs for
compression. There are no functional changes introduced by this
approach.
2. Replace LZO library calls with crypto generic APIs
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.
3. LZ4 compression
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_DEF_COMP_LZ4 to set the default compressor as LZ4.
Compression Benchmarks: https://github.com/lz4/lz4
4. Support to select compression algorithm
Currently the default compression algorithm is selected based on Kconfig.
Introduce a kernel command line parameter "hib_compression" to
override this behaviour.
Users can set "hib_compression" command line parameter to specify
the algorithm.
Usage:
LZO: hib_compression=lzo
LZ4: hib_compression=lz4
LZO is the default compression algorithm used with hibernation.
Nikhil V (4):
PM: hibernate: Rename lzo* to make it generic
PM: hibernate: Move to crypto APIs for LZO compression
PM: hibernate: Add support for LZ4 compression for hibernation
PM: hibernate: Support to select compression algorithm
.../admin-guide/kernel-parameters.txt | 6 +
kernel/power/Kconfig | 25 ++-
kernel/power/hibernate.c | 83 +++++++-
kernel/power/power.h | 19 ++
kernel/power/swap.c | 189 +++++++++++-------
5 files changed, 248 insertions(+), 74 deletions(-)
--
2.17.1
Renaming lzo* to generic names, except for lzo_xxx() APIs. This is
used in the next patch where we move to crypto based APIs for
compression. There are no functional changes introduced by this
approach.
Signed-off-by: Nikhil V <[email protected]>
---
kernel/power/swap.c | 122 ++++++++++++++++++++++----------------------
1 file changed, 61 insertions(+), 61 deletions(-)
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 74edbce2320b..139fb33778a0 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -514,23 +514,23 @@ static int swap_writer_finish(struct swap_map_handle *handle,
}
/* We need to remember how much compressed data we need to read. */
-#define LZO_HEADER sizeof(size_t)
+#define CMP_HEADER sizeof(size_t)
/* Number of pages/bytes we'll compress at one time. */
-#define LZO_UNC_PAGES 32
-#define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE)
+#define UNC_PAGES 32
+#define UNC_SIZE (UNC_PAGES * PAGE_SIZE)
-/* Number of pages/bytes we need for compressed data (worst case). */
-#define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
- LZO_HEADER, PAGE_SIZE)
-#define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE)
+/* Number of pages we need for compressed data (worst case). */
+#define CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(UNC_SIZE) + \
+ CMP_HEADER, PAGE_SIZE)
+#define CMP_SIZE (CMP_PAGES * PAGE_SIZE)
/* Maximum number of threads for compression/decompression. */
-#define LZO_THREADS 3
+#define CMP_THREADS 3
/* Minimum/maximum number of pages for read buffering. */
-#define LZO_MIN_RD_PAGES 1024
-#define LZO_MAX_RD_PAGES 8192
+#define CMP_MIN_RD_PAGES 1024
+#define CMP_MAX_RD_PAGES 8192
/**
@@ -592,8 +592,8 @@ struct crc_data {
wait_queue_head_t go; /* start crc update */
wait_queue_head_t done; /* crc update done */
u32 *crc32; /* points to handle's crc32 */
- size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */
- unsigned char *unc[LZO_THREADS]; /* uncompressed data */
+ size_t *unc_len[CMP_THREADS]; /* uncompressed lengths */
+ unsigned char *unc[CMP_THREADS]; /* uncompressed data */
};
/*
@@ -624,7 +624,7 @@ static int crc32_threadfn(void *data)
return 0;
}
/*
- * Structure used for LZO data compression.
+ * Structure used for data compression.
*/
struct cmp_data {
struct task_struct *thr; /* thread */
@@ -635,15 +635,15 @@ struct cmp_data {
wait_queue_head_t done; /* compression done */
size_t unc_len; /* uncompressed length */
size_t cmp_len; /* compressed length */
- unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
- unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
+ unsigned char unc[UNC_SIZE]; /* uncompressed buffer */
+ unsigned char cmp[CMP_SIZE]; /* compressed buffer */
unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */
};
/*
* Compression function that runs in its own thread.
*/
-static int lzo_compress_threadfn(void *data)
+static int compress_threadfn(void *data)
{
struct cmp_data *d = data;
@@ -660,8 +660,8 @@ static int lzo_compress_threadfn(void *data)
atomic_set(&d->ready, 0);
d->ret = lzo1x_1_compress(d->unc, d->unc_len,
- d->cmp + LZO_HEADER, &d->cmp_len,
- d->wrk);
+ d->cmp + CMP_HEADER, &d->cmp_len,
+ d->wrk);
atomic_set(&d->stop, 1);
wake_up(&d->done);
}
@@ -669,14 +669,14 @@ static int lzo_compress_threadfn(void *data)
}
/**
- * save_image_lzo - Save the suspend image data compressed with LZO.
+ * save_compressed_image - Save the suspend image data after compression.
* @handle: Swap map handle to use for saving the image.
* @snapshot: Image to read data from.
* @nr_to_write: Number of pages to save.
*/
-static int save_image_lzo(struct swap_map_handle *handle,
- struct snapshot_handle *snapshot,
- unsigned int nr_to_write)
+static int save_compressed_image(struct swap_map_handle *handle,
+ struct snapshot_handle *snapshot,
+ unsigned int nr_to_write)
{
unsigned int m;
int ret = 0;
@@ -698,18 +698,18 @@ static int save_image_lzo(struct swap_map_handle *handle,
* footprint.
*/
nr_threads = num_online_cpus() - 1;
- nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
+ nr_threads = clamp_val(nr_threads, 1, CMP_THREADS);
page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
if (!page) {
- pr_err("Failed to allocate LZO page\n");
+ pr_err("Failed to allocate compression page\n");
ret = -ENOMEM;
goto out_clean;
}
data = vzalloc(array_size(nr_threads, sizeof(*data)));
if (!data) {
- pr_err("Failed to allocate LZO data\n");
+ pr_err("Failed to allocate compression data\n");
ret = -ENOMEM;
goto out_clean;
}
@@ -728,7 +728,7 @@ static int save_image_lzo(struct swap_map_handle *handle,
init_waitqueue_head(&data[thr].go);
init_waitqueue_head(&data[thr].done);
- data[thr].thr = kthread_run(lzo_compress_threadfn,
+ data[thr].thr = kthread_run(compress_threadfn,
&data[thr],
"image_compress/%u", thr);
if (IS_ERR(data[thr].thr)) {
@@ -776,7 +776,7 @@ static int save_image_lzo(struct swap_map_handle *handle,
start = ktime_get();
for (;;) {
for (thr = 0; thr < nr_threads; thr++) {
- for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
+ for (off = 0; off < UNC_SIZE; off += PAGE_SIZE) {
ret = snapshot_read_next(snapshot);
if (ret < 0)
goto out_finish;
@@ -816,14 +816,14 @@ static int save_image_lzo(struct swap_map_handle *handle,
ret = data[thr].ret;
if (ret < 0) {
- pr_err("LZO compression failed\n");
+ pr_err("compression failed\n");
goto out_finish;
}
if (unlikely(!data[thr].cmp_len ||
data[thr].cmp_len >
lzo1x_worst_compress(data[thr].unc_len))) {
- pr_err("Invalid LZO compressed length\n");
+ pr_err("Invalid compressed length\n");
ret = -1;
goto out_finish;
}
@@ -839,7 +839,7 @@ static int save_image_lzo(struct swap_map_handle *handle,
* read it.
*/
for (off = 0;
- off < LZO_HEADER + data[thr].cmp_len;
+ off < CMP_HEADER + data[thr].cmp_len;
off += PAGE_SIZE) {
memcpy(page, data[thr].cmp + off, PAGE_SIZE);
@@ -941,7 +941,7 @@ int swsusp_write(unsigned int flags)
if (!error) {
error = (flags & SF_NOCOMPRESS_MODE) ?
save_image(&handle, &snapshot, pages - 1) :
- save_image_lzo(&handle, &snapshot, pages - 1);
+ save_compressed_image(&handle, &snapshot, pages - 1);
}
out_finish:
error = swap_writer_finish(&handle, flags, error);
@@ -1108,7 +1108,7 @@ static int load_image(struct swap_map_handle *handle,
}
/*
- * Structure used for LZO data decompression.
+ * Structure used for data decompression.
*/
struct dec_data {
struct task_struct *thr; /* thread */
@@ -1119,14 +1119,14 @@ struct dec_data {
wait_queue_head_t done; /* decompression done */
size_t unc_len; /* uncompressed length */
size_t cmp_len; /* compressed length */
- unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
- unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
+ unsigned char unc[UNC_SIZE]; /* uncompressed buffer */
+ unsigned char cmp[CMP_SIZE]; /* compressed buffer */
};
/*
* Decompression function that runs in its own thread.
*/
-static int lzo_decompress_threadfn(void *data)
+static int decompress_threadfn(void *data)
{
struct dec_data *d = data;
@@ -1142,9 +1142,9 @@ static int lzo_decompress_threadfn(void *data)
}
atomic_set(&d->ready, 0);
- d->unc_len = LZO_UNC_SIZE;
- d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
- d->unc, &d->unc_len);
+ d->unc_len = UNC_SIZE;
+ d->ret = lzo1x_decompress_safe(d->cmp + CMP_HEADER, d->cmp_len,
+ d->unc, &d->unc_len);
if (clean_pages_on_decompress)
flush_icache_range((unsigned long)d->unc,
(unsigned long)d->unc + d->unc_len);
@@ -1156,14 +1156,14 @@ static int lzo_decompress_threadfn(void *data)
}
/**
- * load_image_lzo - Load compressed image data and decompress them with LZO.
+ * load_compressed_image - Load compressed image data and decompress it.
* @handle: Swap map handle to use for loading data.
* @snapshot: Image to copy uncompressed data into.
* @nr_to_read: Number of pages to load.
*/
-static int load_image_lzo(struct swap_map_handle *handle,
- struct snapshot_handle *snapshot,
- unsigned int nr_to_read)
+static int load_compressed_image(struct swap_map_handle *handle,
+ struct snapshot_handle *snapshot,
+ unsigned int nr_to_read)
{
unsigned int m;
int ret = 0;
@@ -1188,18 +1188,18 @@ static int load_image_lzo(struct swap_map_handle *handle,
* footprint.
*/
nr_threads = num_online_cpus() - 1;
- nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
+ nr_threads = clamp_val(nr_threads, 1, CMP_THREADS);
- page = vmalloc(array_size(LZO_MAX_RD_PAGES, sizeof(*page)));
+ page = vmalloc(array_size(CMP_MAX_RD_PAGES, sizeof(*page)));
if (!page) {
- pr_err("Failed to allocate LZO page\n");
+ pr_err("Failed to allocate compression page\n");
ret = -ENOMEM;
goto out_clean;
}
data = vzalloc(array_size(nr_threads, sizeof(*data)));
if (!data) {
- pr_err("Failed to allocate LZO data\n");
+ pr_err("Failed to allocate compression data\n");
ret = -ENOMEM;
goto out_clean;
}
@@ -1220,7 +1220,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
init_waitqueue_head(&data[thr].go);
init_waitqueue_head(&data[thr].done);
- data[thr].thr = kthread_run(lzo_decompress_threadfn,
+ data[thr].thr = kthread_run(decompress_threadfn,
&data[thr],
"image_decompress/%u", thr);
if (IS_ERR(data[thr].thr)) {
@@ -1261,18 +1261,18 @@ static int load_image_lzo(struct swap_map_handle *handle,
*/
if (low_free_pages() > snapshot_get_image_size())
read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
- read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
+ read_pages = clamp_val(read_pages, CMP_MIN_RD_PAGES, CMP_MAX_RD_PAGES);
for (i = 0; i < read_pages; i++) {
- page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
+ page[i] = (void *)__get_free_page(i < CMP_PAGES ?
GFP_NOIO | __GFP_HIGH :
GFP_NOIO | __GFP_NOWARN |
__GFP_NORETRY);
if (!page[i]) {
- if (i < LZO_CMP_PAGES) {
+ if (i < CMP_PAGES) {
ring_size = i;
- pr_err("Failed to allocate LZO pages\n");
+ pr_err("Failed to allocate compression pages\n");
ret = -ENOMEM;
goto out_clean;
} else {
@@ -1343,13 +1343,13 @@ static int load_image_lzo(struct swap_map_handle *handle,
data[thr].cmp_len = *(size_t *)page[pg];
if (unlikely(!data[thr].cmp_len ||
data[thr].cmp_len >
- lzo1x_worst_compress(LZO_UNC_SIZE))) {
- pr_err("Invalid LZO compressed length\n");
+ lzo1x_worst_compress(UNC_SIZE))) {
+ pr_err("Invalid compressed length\n");
ret = -1;
goto out_finish;
}
- need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
+ need = DIV_ROUND_UP(data[thr].cmp_len + CMP_HEADER,
PAGE_SIZE);
if (need > have) {
if (eof > 1) {
@@ -1360,7 +1360,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
}
for (off = 0;
- off < LZO_HEADER + data[thr].cmp_len;
+ off < CMP_HEADER + data[thr].cmp_len;
off += PAGE_SIZE) {
memcpy(data[thr].cmp + off,
page[pg], PAGE_SIZE);
@@ -1377,7 +1377,7 @@ static int load_image_lzo(struct swap_map_handle *handle,
/*
* Wait for more data while we are decompressing.
*/
- if (have < LZO_CMP_PAGES && asked) {
+ if (have < CMP_PAGES && asked) {
ret = hib_wait_io(&hb);
if (ret)
goto out_finish;
@@ -1395,14 +1395,14 @@ static int load_image_lzo(struct swap_map_handle *handle,
ret = data[thr].ret;
if (ret < 0) {
- pr_err("LZO decompression failed\n");
+ pr_err("decompression failed\n");
goto out_finish;
}
if (unlikely(!data[thr].unc_len ||
- data[thr].unc_len > LZO_UNC_SIZE ||
- data[thr].unc_len & (PAGE_SIZE - 1))) {
- pr_err("Invalid LZO uncompressed length\n");
+ data[thr].unc_len > UNC_SIZE ||
+ data[thr].unc_len & (PAGE_SIZE - 1))) {
+ pr_err("Invalid uncompressed length\n");
ret = -1;
goto out_finish;
}
@@ -1499,7 +1499,7 @@ int swsusp_read(unsigned int *flags_p)
if (!error) {
error = (*flags_p & SF_NOCOMPRESS_MODE) ?
load_image(&handle, &snapshot, header->pages - 1) :
- load_image_lzo(&handle, &snapshot, header->pages - 1);
+ load_compressed_image(&handle, &snapshot, header->pages - 1);
}
swap_reader_finish(&handle);
end:
--
2.17.1
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 <[email protected]>
---
.../admin-guide/kernel-parameters.txt | 6 ++++
kernel/power/hibernate.c | 29 ++++++++++++++++++-
2 files changed, 34 insertions(+), 1 deletion(-)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 0a1731a0f0ef..3f5f3e453db1 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1734,6 +1734,12 @@
(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 87be8cda9b9b..22296a7b640c 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -742,7 +742,8 @@ 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;
@@ -1416,6 +1417,31 @@ 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;
+ }
+ }
+ 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);
@@ -1423,3 +1449,4 @@ __setup("hibernate=", hibernate_setup);
__setup("resumewait", resumewait_setup);
__setup("resumedelay=", resumedelay_setup);
__setup("nohibernate", nohibernate_setup);
+__setup("hib_compression=", compression_setup);
--
2.17.1
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 <[email protected]>
---
kernel/power/Kconfig | 5 +++++
kernel/power/hibernate.c | 25 ++++++++++++++++++++++---
kernel/power/power.h | 14 ++++++++++++++
3 files changed, 41 insertions(+), 3 deletions(-)
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index bc449d05c23d..03e2cd652f20 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -100,11 +100,16 @@ 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 ed9901b75333..87be8cda9b9b 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -721,6 +721,9 @@ static int load_image_and_restore(bool snapshot_test)
return error;
}
+#define COMPRESSION_ALGO_LZO "lzo"
+#define COMPRESSION_ALGO_LZ4 "lz4"
+
/**
* hibernate - Carry out system hibernation, including saving the image.
*/
@@ -780,11 +783,24 @@ 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();
@@ -974,7 +990,10 @@ 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 d9bf10d92546..026d40e0972a 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);
--
2.17.1
On 9/26/2023 2:27 PM, Nikhil V wrote:
> This patch series covers the following:
> 1. Renaming lzo* to generic names, except for lzo_xxx() APIs. This is
> used in the next patch where we move to crypto based APIs for
> compression. There are no functional changes introduced by this
> approach.
>
>
> 2. Replace LZO library calls with crypto generic APIs
>
> 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.
>
>
> 3. LZ4 compression
> 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_DEF_COMP_LZ4 to set the default compressor as LZ4.
>
> Compression Benchmarks: https://github.com/lz4/lz4
>
> 4. Support to select compression algorithm
>
> Currently the default compression algorithm is selected based on Kconfig.
> Introduce a kernel command line parameter "hib_compression" to
> override this behaviour.
>
> Users can set "hib_compression" command line parameter to specify
> the algorithm.
> Usage:
> LZO: hib_compression=lzo
> LZ4: hib_compression=lz4
> LZO is the default compression algorithm used with hibernation.
>
> Nikhil V (4):
> PM: hibernate: Rename lzo* to make it generic
> PM: hibernate: Move to crypto APIs for LZO compression
> PM: hibernate: Add support for LZ4 compression for hibernation
> PM: hibernate: Support to select compression algorithm
>
> .../admin-guide/kernel-parameters.txt | 6 +
> kernel/power/Kconfig | 25 ++-
> kernel/power/hibernate.c | 83 +++++++-
> kernel/power/power.h | 19 ++
> kernel/power/swap.c | 189 +++++++++++-------
> 5 files changed, 248 insertions(+), 74 deletions(-)
>
Hi,
Could you please let me know if you have any concerns/comments on this
approach? If there are no comments, I could push another patch series
with PATCH tag for review.
Thanks
Nikhil V
On Tue, Sep 26, 2023 at 02:27:10PM +0530, Nikhil V wrote:
> This patch series covers the following:
> 1. Renaming lzo* to generic names, except for lzo_xxx() APIs. This is
> used in the next patch where we move to crypto based APIs for
> compression. There are no functional changes introduced by this
> approach.
>
>
> 2. Replace LZO library calls with crypto generic APIs
>
> 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.
>
>
> 3. LZ4 compression
> 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_DEF_COMP_LZ4 to set the default compressor as LZ4.
>
> Compression Benchmarks: https://github.com/lz4/lz4
>
> 4. Support to select compression algorithm
>
> Currently the default compression algorithm is selected based on Kconfig.
> Introduce a kernel command line parameter "hib_compression" to
> override this behaviour.
>
> Users can set "hib_compression" command line parameter to specify
> the algorithm.
> Usage:
> LZO: hib_compression=lzo
> LZ4: hib_compression=lz4
> LZO is the default compression algorithm used with hibernation.
>
> Nikhil V (4):
> PM: hibernate: Rename lzo* to make it generic
> PM: hibernate: Move to crypto APIs for LZO compression
> PM: hibernate: Add support for LZ4 compression for hibernation
> PM: hibernate: Support to select compression algorithm
>
> .../admin-guide/kernel-parameters.txt | 6 +
> kernel/power/Kconfig | 25 ++-
> kernel/power/hibernate.c | 83 +++++++-
> kernel/power/power.h | 19 ++
> kernel/power/swap.c | 189 +++++++++++-------
> 5 files changed, 248 insertions(+), 74 deletions(-)
>
I have tested this series on x86 QEMU with v6.6-rc3 (plus another patch
from pm-next tree i.e "PM: hibernate: use __get_safe_page() rather than
touching the list"). It works as advertised.
Thanks,
Pavan
On Tue, Sep 26, 2023 at 02:27:14PM +0530, Nikhil V wrote:
> +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;
> + }
> + }
> + 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);
> @@ -1423,3 +1449,4 @@ __setup("hibernate=", hibernate_setup);
> __setup("resumewait", resumewait_setup);
> __setup("resumedelay=", resumedelay_setup);
> __setup("nohibernate", nohibernate_setup);
> +__setup("hib_compression=", compression_setup);
> --
If I pass hib_compression=lz4 without enabling CONFIG_CRYPTO_LZ4, It
silently makes the compression to lzo which is expected from this code.
It would be good if an error/info message is printed in
compression_setup() which this happens.
Thanks,
Pavan