[zram] Many Invaild IO with latest zram from

I have a way too many Invaild IO. Which is interesing because everything is 
working, also I have it on two independent boxes, one is 32bit with 2.6.34 
kernel and another is 64bit with 2.6.35 kernel. Before test I did fresh clone 
of mercurial repo. Below test output is from 2.6.35 64bit box, on 32bit 2.6.34 
one I use zram as swap.

ragnarok compcache # make  
[...]
ragnarok compcache # insmod zram.ko
ragnarok compcache # mkfs.ext4 /dev/zram0
[...]
ragnarok compcache # mount /dev/zram0 /tmp
ragnarok compcache # bash sub-projects/scripts/zram_stats 
/sys/block/zram0
disksize:         1035776000 
num_reads:               172 
num_writes:             8185 
invalid_io:             8356 
notify_free:               0 
discard:                   0 
zero_pages:             8059 
orig_data_size:       409600 
compr_data_size:       12277 
mem_used_total:        16384 
avg_compr_ratio:           2 %
mem_overhead:             33 %

Original issue reported on code.google.com by jabberu...@gmail.com on 9 Sep 2010 at 4:50

mfrw / compcache

[zram] Many Invaild IO with latest zram from #72