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.
Changes in v3:
- Rebased to v6.8-rc1 after resolving the minor conflicts.
- Link to v2:
https://lore.kernel.org/all/[email protected]/
Changes in v2:
- Fixed build issues reported by kernel test robot for ARCH=sh, [1].
[1] https://lore.kernel.org/oe-kbuild-all/[email protected]/
- Link to v1:
https://lore.kernel.org/all/[email protected]/
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 | 26 ++-
kernel/power/hibernate.c | 85 +++++++-
kernel/power/power.h | 19 ++
kernel/power/swap.c | 189 +++++++++++-------
5 files changed, 251 insertions(+), 74 deletions(-)
base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d
--
2.17.1
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 <[email protected]>
---
kernel/power/Kconfig | 21 +++++++-
kernel/power/hibernate.c | 33 +++++++++++++
kernel/power/power.h | 5 ++
kernel/power/swap.c | 101 +++++++++++++++++++++++++++++----------
4 files changed, 132 insertions(+), 28 deletions(-)
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 4b31629c5be4..d4167159bae8 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -39,9 +39,9 @@ config HIBERNATION
bool "Hibernation (aka 'suspend to disk')"
depends on SWAP && ARCH_HIBERNATION_POSSIBLE
select HIBERNATE_CALLBACKS
- select LZO_COMPRESS
- select LZO_DECOMPRESS
select CRC32
+ select CRYPTO
+ select CRYPTO_LZO
help
Enable the suspend to disk (STD) functionality, which is usually
called "hibernation" in user interfaces. STD checkpoints the
@@ -92,6 +92,23 @@ config HIBERNATION_SNAPSHOT_DEV
If in doubt, say Y.
+choice
+ prompt "Default compressor"
+ default HIBERNATION_COMP_LZO
+ depends on HIBERNATION
+
+config HIBERNATION_COMP_LZO
+ bool "lzo"
+ depends on CRYPTO_LZO
+
+endchoice
+
+config HIBERNATION_DEF_COMP
+ string
+ default "lzo" if HIBERNATION_COMP_LZO
+ help
+ Default compressor to be used for hibernation.
+
config PM_STD_PARTITION
string "Default resume partition"
depends on HIBERNATION
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;
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 8499a39c62f4..b1befc65e6ee 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -6,6 +6,7 @@
#include <linux/compiler.h>
#include <linux/cpu.h>
#include <linux/cpuidle.h>
+#include <linux/crypto.h>
struct swsusp_info {
struct new_utsname uts;
@@ -54,6 +55,10 @@ asmlinkage int swsusp_save(void);
/* kernel/power/hibernate.c */
extern bool freezer_test_done;
+extern char hib_comp_algo[CRYPTO_MAX_ALG_NAME];
+
+/* kernel/power/swap.c */
+extern unsigned int swsusp_header_flags;
extern int hibernation_snapshot(int platform_mode);
extern int hibernation_restore(int platform_mode);
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 35c62f91c13b..6513035f2f7f 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -23,7 +23,6 @@
#include <linux/swapops.h>
#include <linux/pm.h>
#include <linux/slab.h>
-#include <linux/lzo.h>
#include <linux/vmalloc.h>
#include <linux/cpumask.h>
#include <linux/atomic.h>
@@ -339,6 +338,13 @@ static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
return error;
}
+/*
+ * Hold the swsusp_header flag. This is used in software_resume() in
+ * 'kernel/power/hibernate' to check if the image is compressed and query
+ * for the compression algorithm support(if so).
+ */
+unsigned int swsusp_header_flags;
+
/**
* swsusp_swap_check - check if the resume device is a swap device
* and get its index (if so)
@@ -514,6 +520,12 @@ static int swap_writer_finish(struct swap_map_handle *handle,
return error;
}
+/*
+ * Bytes we need for compressed data in worst case. We assume(limitation)
+ * this is the worst of all the compression algorithms.
+ */
+#define bytes_worst_compress(x) ((x) + ((x) / 16) + 64 + 3 + 2)
+
/* We need to remember how much compressed data we need to read. */
#define CMP_HEADER sizeof(size_t)
@@ -522,7 +534,7 @@ static int swap_writer_finish(struct swap_map_handle *handle,
#define UNC_SIZE (UNC_PAGES * PAGE_SIZE)
/* Number of pages we need for compressed data (worst case). */
-#define CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(UNC_SIZE) + \
+#define CMP_PAGES DIV_ROUND_UP(bytes_worst_compress(UNC_SIZE) + \
CMP_HEADER, PAGE_SIZE)
#define CMP_SIZE (CMP_PAGES * PAGE_SIZE)
@@ -533,7 +545,6 @@ static int swap_writer_finish(struct swap_map_handle *handle,
#define CMP_MIN_RD_PAGES 1024
#define CMP_MAX_RD_PAGES 8192
-
/**
* save_image - save the suspend image data
*/
@@ -629,6 +640,7 @@ static int crc32_threadfn(void *data)
*/
struct cmp_data {
struct task_struct *thr; /* thread */
+ struct crypto_comp *cc; /* crypto compressor stream */
atomic_t ready; /* ready to start flag */
atomic_t stop; /* ready to stop flag */
int ret; /* return code */
@@ -638,15 +650,18 @@ struct cmp_data {
size_t cmp_len; /* compressed length */
unsigned char unc[UNC_SIZE]; /* uncompressed buffer */
unsigned char cmp[CMP_SIZE]; /* compressed buffer */
- unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */
};
+/* Indicates the image size after compression */
+static atomic_t compressed_size = ATOMIC_INIT(0);
+
/*
* Compression function that runs in its own thread.
*/
static int compress_threadfn(void *data)
{
struct cmp_data *d = data;
+ unsigned int cmp_len = 0;
while (1) {
wait_event(d->go, atomic_read_acquire(&d->ready) ||
@@ -660,9 +675,13 @@ static int compress_threadfn(void *data)
}
atomic_set(&d->ready, 0);
- d->ret = lzo1x_1_compress(d->unc, d->unc_len,
- d->cmp + CMP_HEADER, &d->cmp_len,
- d->wrk);
+ cmp_len = CMP_SIZE - CMP_HEADER;
+ d->ret = crypto_comp_compress(d->cc, d->unc, d->unc_len,
+ d->cmp + CMP_HEADER,
+ &cmp_len);
+ d->cmp_len = cmp_len;
+
+ atomic_set(&compressed_size, atomic_read(&compressed_size) + d->cmp_len);
atomic_set_release(&d->stop, 1);
wake_up(&d->done);
}
@@ -694,6 +713,8 @@ static int save_compressed_image(struct swap_map_handle *handle,
hib_init_batch(&hb);
+ atomic_set(&compressed_size, 0);
+
/*
* We'll limit the number of threads for compression to limit memory
* footprint.
@@ -703,14 +724,14 @@ static int save_compressed_image(struct swap_map_handle *handle,
page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
if (!page) {
- pr_err("Failed to allocate compression page\n");
+ pr_err("Failed to allocate %s page\n", hib_comp_algo);
ret = -ENOMEM;
goto out_clean;
}
data = vzalloc(array_size(nr_threads, sizeof(*data)));
if (!data) {
- pr_err("Failed to allocate compression data\n");
+ pr_err("Failed to allocate %s data\n", hib_comp_algo);
ret = -ENOMEM;
goto out_clean;
}
@@ -729,6 +750,13 @@ static int save_compressed_image(struct swap_map_handle *handle,
init_waitqueue_head(&data[thr].go);
init_waitqueue_head(&data[thr].done);
+ data[thr].cc = crypto_alloc_comp(hib_comp_algo, 0, 0);
+ if (IS_ERR_OR_NULL(data[thr].cc)) {
+ pr_err("Could not allocate comp stream %ld\n", PTR_ERR(data[thr].cc));
+ ret = -EFAULT;
+ goto out_clean;
+ }
+
data[thr].thr = kthread_run(compress_threadfn,
&data[thr],
"image_compress/%u", thr);
@@ -767,7 +795,7 @@ static int save_compressed_image(struct swap_map_handle *handle,
*/
handle->reqd_free_pages = reqd_free_pages();
- pr_info("Using %u thread(s) for compression\n", nr_threads);
+ pr_info("Using %u thread(s) for %s compression\n", nr_threads, hib_comp_algo);
pr_info("Compressing and saving image data (%u pages)...\n",
nr_to_write);
m = nr_to_write / 10;
@@ -817,14 +845,14 @@ static int save_compressed_image(struct swap_map_handle *handle,
ret = data[thr].ret;
if (ret < 0) {
- pr_err("compression failed\n");
+ pr_err("%s compression failed\n", hib_comp_algo);
goto out_finish;
}
if (unlikely(!data[thr].cmp_len ||
data[thr].cmp_len >
- lzo1x_worst_compress(data[thr].unc_len))) {
- pr_err("Invalid compressed length\n");
+ bytes_worst_compress(data[thr].unc_len))) {
+ pr_err("Invalid %s compressed length\n", hib_comp_algo);
ret = -1;
goto out_finish;
}
@@ -862,6 +890,9 @@ static int save_compressed_image(struct swap_map_handle *handle,
if (!ret)
pr_info("Image saving done\n");
swsusp_show_speed(start, stop, nr_to_write, "Wrote");
+ pr_info("Image size after compression: %d kbytes\n",
+ (atomic_read(&compressed_size) / 1024));
+
out_clean:
hib_finish_batch(&hb);
if (crc) {
@@ -870,9 +901,12 @@ static int save_compressed_image(struct swap_map_handle *handle,
kfree(crc);
}
if (data) {
- for (thr = 0; thr < nr_threads; thr++)
+ for (thr = 0; thr < nr_threads; thr++) {
if (data[thr].thr)
kthread_stop(data[thr].thr);
+ if (data[thr].cc)
+ crypto_free_comp(data[thr].cc);
+ }
vfree(data);
}
if (page) free_page((unsigned long)page);
@@ -1113,6 +1147,7 @@ static int load_image(struct swap_map_handle *handle,
*/
struct dec_data {
struct task_struct *thr; /* thread */
+ struct crypto_comp *cc; /* crypto compressor stream */
atomic_t ready; /* ready to start flag */
atomic_t stop; /* ready to stop flag */
int ret; /* return code */
@@ -1130,6 +1165,7 @@ struct dec_data {
static int decompress_threadfn(void *data)
{
struct dec_data *d = data;
+ unsigned int unc_len = 0;
while (1) {
wait_event(d->go, atomic_read_acquire(&d->ready) ||
@@ -1143,9 +1179,11 @@ static int decompress_threadfn(void *data)
}
atomic_set(&d->ready, 0);
- d->unc_len = UNC_SIZE;
- d->ret = lzo1x_decompress_safe(d->cmp + CMP_HEADER, d->cmp_len,
- d->unc, &d->unc_len);
+ unc_len = UNC_SIZE;
+ d->ret = crypto_comp_decompress(d->cc, d->cmp + CMP_HEADER, d->cmp_len,
+ d->unc, &unc_len);
+ d->unc_len = unc_len;
+
if (clean_pages_on_decompress)
flush_icache_range((unsigned long)d->unc,
(unsigned long)d->unc + d->unc_len);
@@ -1193,14 +1231,14 @@ static int load_compressed_image(struct swap_map_handle *handle,
page = vmalloc(array_size(CMP_MAX_RD_PAGES, sizeof(*page)));
if (!page) {
- pr_err("Failed to allocate compression page\n");
+ pr_err("Failed to allocate %s page\n", hib_comp_algo);
ret = -ENOMEM;
goto out_clean;
}
data = vzalloc(array_size(nr_threads, sizeof(*data)));
if (!data) {
- pr_err("Failed to allocate compression data\n");
+ pr_err("Failed to allocate %s data\n", hib_comp_algo);
ret = -ENOMEM;
goto out_clean;
}
@@ -1221,6 +1259,13 @@ static int load_compressed_image(struct swap_map_handle *handle,
init_waitqueue_head(&data[thr].go);
init_waitqueue_head(&data[thr].done);
+ data[thr].cc = crypto_alloc_comp(hib_comp_algo, 0, 0);
+ if (IS_ERR_OR_NULL(data[thr].cc)) {
+ pr_err("Could not allocate comp stream %ld\n", PTR_ERR(data[thr].cc));
+ ret = -EFAULT;
+ goto out_clean;
+ }
+
data[thr].thr = kthread_run(decompress_threadfn,
&data[thr],
"image_decompress/%u", thr);
@@ -1273,7 +1318,7 @@ static int load_compressed_image(struct swap_map_handle *handle,
if (!page[i]) {
if (i < CMP_PAGES) {
ring_size = i;
- pr_err("Failed to allocate compression pages\n");
+ pr_err("Failed to allocate %s pages\n", hib_comp_algo);
ret = -ENOMEM;
goto out_clean;
} else {
@@ -1283,7 +1328,7 @@ static int load_compressed_image(struct swap_map_handle *handle,
}
want = ring_size = i;
- pr_info("Using %u thread(s) for decompression\n", nr_threads);
+ pr_info("Using %u thread(s) for %s decompression\n", nr_threads, hib_comp_algo);
pr_info("Loading and decompressing image data (%u pages)...\n",
nr_to_read);
m = nr_to_read / 10;
@@ -1344,8 +1389,8 @@ static int load_compressed_image(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(UNC_SIZE))) {
- pr_err("Invalid compressed length\n");
+ bytes_worst_compress(UNC_SIZE))) {
+ pr_err("Invalid %s compressed length\n", hib_comp_algo);
ret = -1;
goto out_finish;
}
@@ -1396,14 +1441,14 @@ static int load_compressed_image(struct swap_map_handle *handle,
ret = data[thr].ret;
if (ret < 0) {
- pr_err("decompression failed\n");
+ pr_err("%s decompression failed\n", hib_comp_algo);
goto out_finish;
}
if (unlikely(!data[thr].unc_len ||
data[thr].unc_len > UNC_SIZE ||
data[thr].unc_len & (PAGE_SIZE - 1))) {
- pr_err("Invalid uncompressed length\n");
+ pr_err("Invalid %s uncompressed length\n", hib_comp_algo);
ret = -1;
goto out_finish;
}
@@ -1464,9 +1509,12 @@ static int load_compressed_image(struct swap_map_handle *handle,
kfree(crc);
}
if (data) {
- for (thr = 0; thr < nr_threads; thr++)
+ for (thr = 0; thr < nr_threads; thr++) {
if (data[thr].thr)
kthread_stop(data[thr].thr);
+ if (data[thr].cc)
+ crypto_free_comp(data[thr].cc);
+ }
vfree(data);
}
vfree(page);
@@ -1535,6 +1583,7 @@ int swsusp_check(bool exclusive)
if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
+ swsusp_header_flags = swsusp_header->flags;
/* Reset swap signature now */
error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
swsusp_resume_block,
--
2.17.1
On Mon, Jan 22, 2024 at 2:16 PM Nikhil V <[email protected]> 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.
>
>
> Changes in v3:
> - Rebased to v6.8-rc1 after resolving the minor conflicts.
> - Link to v2:
> https://lore.kernel.org/all/[email protected]/
I've applied the first 3 patches in the series (as 6.9 material), but
I'm not particularly happy with the last one.
First off, I'm not sure if a kernel command line parameter is the most
convenient way of selecting the compression algorithm. Since (AFAICS)
the restore kernel will detect the compression algo in use anyway (or
at least it can be made do so), a modparam should work for this and it
would be far more convenient to use.
Second, if I can be convinced that indeed, using a kernel command line
option for this is the way to go, I don't particularly like the name
used in that patch.
Please feel free to send a replacement for patch [4/4] separately.
Thanks!
On 1/31/2024 7:50 PM, Rafael J. Wysocki wrote:
> On Mon, Jan 22, 2024 at 2:16 PM Nikhil V <[email protected]> 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.
>>
>>
>> Changes in v3:
>> - Rebased to v6.8-rc1 after resolving the minor conflicts.
>> - Link to v2:
>> https://lore.kernel.org/all/[email protected]/
>
> I've applied the first 3 patches in the series (as 6.9 material), but
> I'm not particularly happy with the last one.
>
> First off, I'm not sure if a kernel command line parameter is the most
> convenient way of selecting the compression algorithm. Since (AFAICS)
> the restore kernel will detect the compression algo in use anyway (or
> at least it can be made do so), a modparam should work for this and it
> would be far more convenient to use.
>
> Second, if I can be convinced that indeed, using a kernel command line
> option for this is the way to go, I don't particularly like the name
> used in that patch.
>
> Please feel free to send a replacement for patch [4/4] separately.
>
> Thanks!
Hi @Rafael,
Thanks for the update.
Regarding patch[4/4], will work on modifying the code as mentioned by
adding module parameter instead of kernel cmdline parameter. Will send a
separate patch for this after testing with the changes. Thanks for the
input.
Thanks,
Nikhil V