Messages in this thread | | | Date | Wed, 29 Nov 2023 15:49:34 +0530 | Subject | Re: [PATCH RESEND v2 0/4] PM: hibernate: LZ4 compression support | From | Nikhil V <> |
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On 11/15/2023 5:52 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. > > > Changes in v2: > - Fixed build issues reported by kernel test robot for ARCH=sh, [1]. > [1] https://lore.kernel.org/oe-kbuild-all/202310171226.pLUPeuC7-lkp@intel.com/ > > 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: b85ea95d086471afb4ad062012a4d73cd328fa86
Hi @Rafael/@Pavel/@Len,
Could you please let me know if you have any concerns on this approach?
FYI: We have tested this on QEMU and its working fine.
Logs(suspend): [ 75.242227] PM: Using 3 thread(s) for lz4 compression [ 75.243043] PM: Compressing and saving image data (17495 pages)... [ 75.243917] PM: Image saving progress: 0% [ 75.261727] PM: Image saving progress: 10% [ 75.277968] PM: Image saving progress: 20% [ 75.290927] PM: Image saving progress: 30% [ 75.305186] PM: Image saving progress: 40% [ 75.318252] PM: Image saving progress: 50% [ 75.330310] PM: Image saving progress: 60% [ 75.345906] PM: Image saving progress: 70% [ 75.359054] PM: Image saving progress: 80% [ 75.372176] PM: Image saving progress: 90% [ 75.388411] PM: Image saving progress: 100% [ 75.389775] PM: Image saving done [ 75.390397] PM: hibernation: Wrote 69980 kbytes in 0.14 seconds (499.85 MB/s) [ 75.391591] PM: Image size after compression: 28242 kbytes [ 75.393089] PM: S| [ 75.399784] sd 0:0:0:0: [sda] Synchronizing SCSI cache [ 75.439170] sd 0:0:0:0: [sda] Stopping disk [ 75.501461] ACPI: PM: Preparing to enter system sleep state S5 [ 75.502766] reboot: Power down
Logs(resume): [ 1.063248] PM: hibernation: resume from hibernation [ 1.072868] Freezing user space processes [ 1.073707] Freezing user space processes completed (elapsed 0.000 seconds) [ 1.075192] OOM killer disabled. [ 1.075837] Freezing remaining freezable tasks [ 1.078010] Freezing remaining freezable tasks completed (elapsed 0.001 seconds) [ 1.087489] PM: Using 3 thread(s) for lz4 decompression [ 1.088570] PM: Loading and decompressing image data (17495 pages)... [ 1.125549] PM: Image loading progress: 0% [ 1.190380] PM: Image loading progress: 10% [ 1.204963] PM: Image loading progress: 20% [ 1.218988] PM: Image loading progress: 30% [ 1.233697] PM: Image loading progress: 40% [ 1.248658] PM: Image loading progress: 50% [ 1.262910] PM: Image loading progress: 60% [ 1.276966] PM: Image loading progress: 70% [ 1.290517] PM: Image loading progress: 80% [ 1.305427] PM: Image loading progress: 90% [ 1.320666] PM: Image loading progress: 100% [ 1.321866] PM: Image loading done [ 1.322599] PM: hibernation: Read 69980 kbytes in 0.23 seconds (304.26 MB/s) [ 1.324795] printk: Suspending console(s) (use no_console_suspend to debug) [ 74.943801] ata1.00: Entering standby power mode
Thanks, Nikhil V
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