Re: [PATCH 0/5] mm: unify default compressor algorithm for zram/zswap

[Kefeng Wang <wangkefeng.wang@huawei.com>]

On 2024/2/23 12:46, Yosry Ahmed wrote:
> On Thu, Feb 22, 2024 at 7:56 PM Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
>>
>> Both zram and zswap are used to reduce memory usage by compressing cold
>> page, a default compressor algorithm is selected from kinds of compressor
>> algorithm as the default one from very similar Kconfig, also both of
>> them could change the algorithm by sysfs interfaces, so unify the
>> default compressor algorithm to cleanup the default algorithm chosen.
> 
> Both zswap and zram *can* be used for compressed swap, but zram is a
> generic block device that has other use cases, see
> https://docs.kernel.org/admin-guide/blockdev/zram.html.
> 
> For starters, making zram depend on SWAP may break some of those use cases.
> 
> Otherwise, I don't immediately see the benefit of unifying the config
> options for two independent subsystems just because they both use
> "compression". The reduction of the config options is nice, but in
> this case I am not sure it's doing more good than harm. Also, most
> people use either zswap or zram in my experience, so they don't really
> have to configure both anyway.
Fair enough, then, please ignore the patches, thanks.
> 
>>
>> Kefeng Wang (5):
>>    zram: zcomp: remove zcomp_set_max_streams() declaration
>>    zram: make zram depends on SWAP
>>    zram: support deflate compressor
>>    mm: zswap: default to lzo-rle instead of lzo
>>    mm: unify default compressor algorithm for zswap and zram
>>
>>   Documentation/admin-guide/mm/zswap.rst     |   2 +-
>>   arch/loongarch/configs/loongson3_defconfig |   2 +-
>>   drivers/block/zram/Kconfig                 |  44 +------
>>   drivers/block/zram/zcomp.c                 |   3 +
>>   drivers/block/zram/zcomp.h                 |   1 -
>>   drivers/block/zram/zram_drv.c              |   2 +-
>>   mm/Kconfig                                 | 134 +++++++++++----------
>>   mm/zswap.c                                 |   8 +-
>>   8 files changed, 83 insertions(+), 113 deletions(-)
>>
>> --
>> 2.27.0
>>