Re: [LTP] min_free_kbytes incorrect results

Cyril Hrubis
2014-12-04T14:03:57Z

Hi!
> I've been running 'min_free_kbytes' from 'runtest/mm', but everytime I'm
> getting an incorrect value on read. I've tried this test on different
> machines (different architectures) and with different versions of ltp,
> but I'm getting the same error on read. I've looked at the test, but the
> code seems fine. If anybody has any ideea why this isn't working please
> let me know.
>
> The following log was generated using an up-to-date Arch Linux x64 using
> kernel: 3.17.4-1
> -------------------------------------------------------------------------------------------------
> min_free_kbytes 0 TINFO : set overcommit_memory to 2
> min_free_kbytes 0 TINFO : set min_free_kbytes to 67584
> min_free_kbytes 1 TBROK : min_free_kbytes = 6, but expect 67584

This failure comes from function set_sys_tune() from
testcases/kernel/mem/lib/mem.c

What the code does is to write to the specified file in /sys and then
reads it back to verify its content. And it looks like the number read
back is truncated so something seems to be broken.

--
Cyril Hrubis
chrubis@suse.cz