[LTP] [PATCH v2] kernel/device-drivers/zram/zram01.sh : don't fill from /dev/zero

[Richard Palethorpe]

Hello,

Ian Wienand <iwienand@redhat.com> writes:

> I have a system (virtualized aarch64, 4.18.0 kernel) that is
> consistently failing the zram01.sh test as it tries to divide the
> memory stats by zero.  This has been reported before at [1] without
> resolution.
>
> After some investigation [2] my conclusion is that this zero value
> represents the pages allocated for compressed storage in the zram
> device, and due to same-page deduplication the extant method of
> filling with all-zeros can indeed lead us to not having any compressed
> data to measure.
>
> This is visible in the occasional divide-by-zero error, but in the
> bigger picture means this test is not exercising the compression path
> as desired.

Do zram{02,03} already do something similar?

In any case I'd prefer to see a zram04 written in C if some coverage is
missing.

-- 
Thank you,
Richard.