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
