[LTP] [PATCH v2] syscalls/readahead02: limit max readahead to backing device max_readahead_kb

[Jan Stancek]

----- Original Message -----
> > > Try to set bdi limit of test device on setup() to testfile_size before
> > > reading
> > > back the value?
> > > If that fails try testfile_size / 2 etc.
> >
> > Maybe, but we would need to start lower (2M). Kernels prior to
> > commit 600e19afc5f8a6c18ea49cee9511c5797db02391 will just ignore it.
> >
> 
> Ah. Thanks for the reference.
> But kernels prior to this commit SHOULD fail the test if they
> don't comply with explicit readahead() request that is below 2M

Yes, agreed.

> and bdi limit.

What I meant was, that we can try bumping bdi limit, but our
max readahead length has to be capped to MIN(bdi limit, 2M).

Does that make sense?

> That is the case that the commit sets to fix. No?
> 
> Thanks,
> Amir.
>