Re: [RFC][PATCH 00/10] zsmalloc auto-compaction

[Sergey Senozhatsky]

On (05/30/15 00:05), Sergey Senozhatsky wrote:
> RFC
> 
> this is 4.3 material, but I wanted to publish it sooner to gain
> responses and to settle it down before 4.3 merge window opens.
> 
> in short, this series tweaks zsmalloc's compaction and adds
> auto-compaction support. auto-compaction is not aimed to replace
> manual compaction, intead it's supposed to be good enough. yet
> it surely slows down zsmalloc in some scenarious. whilst simple
> un-tar test didn't show any significant performance difference
> 
> 
> quote from commit 0007:
> 
> this test copies a 1.3G linux kernel tar to mounted zram disk,
> and extracts it.
> 

[..]


Hello,

I've a v2:
-- squashed and re-order some of the patches;
-- run iozone with lockdep disabled.

=== quote ===

    auto-compaction should not affect read-only tests, so we are interested
    in write-only and read-write (mixed) tests, but I'll post complete test
    stats:
    
    iozone -t 3 -R -r 16K -s 60M -I +Z
    ext4, 2g zram0 device, lzo, 4 compression streams max
    
           test           base       auto-compact (compacted 67904 objs)
       Initial write   2474943.62          2490551.69
             Rewrite   3656121.38          3002796.31
                Read   12068187.50         12044105.25
             Re-read   12009777.25         11930537.50
        Reverse Read   10858884.25         10388252.50
         Stride read   10715304.75         10429308.00
         Random read   10597970.50         10502978.75
      Mixed workload   8517269.00          8701298.12
        Random write   3595597.00          3465174.38
              Pwrite   2507361.25          2553224.50
               Pread   5380608.28          5340646.03
              Fwrite   6123863.62          6130514.25
               Fread   12006438.50         11936981.25
    
    mm_stat after the test
    
    base:
    cat /sys/block/zram0/mm_stat
    378834944  5748695  7446528        0  7450624    16318        0
    
    auto-compaction:
    cat /sys/block/zram0/mm_stat
    378892288  5754987  7397376        0  7397376    16304    67904

===

	-ss

> 
> 
> Sergey Senozhatsky (10):
>   zsmalloc: drop unused variable `nr_to_migrate'
>   zsmalloc: always keep per-class stats
>   zsmalloc: introduce zs_can_compact() function
>   zsmalloc: cosmetic compaction code adjustments
>   zsmalloc: add `num_migrated' to zs_pool
>   zsmalloc: move compaction functions
>   zsmalloc: introduce auto-compact support
>   zsmalloc: export zs_pool `num_migrated'
>   zram: remove `num_migrated' from zram_stats
>   zsmalloc: lower ZS_ALMOST_FULL waterline
> 
>  drivers/block/zram/zram_drv.c |  12 +-
>  drivers/block/zram/zram_drv.h |   1 -
>  include/linux/zsmalloc.h      |   1 +
>  mm/zsmalloc.c                 | 578 +++++++++++++++++++++---------------------
>  4 files changed, 296 insertions(+), 296 deletions(-)
> 
> -- 
> 2.4.2.337.gfae46aa
> 
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