Re: [PATCH v3] slab_arena: Enhance slab_arena_create to support madvise hints

[Cyrill Gorcunov <gorcunov@gmail.com>]

On Wed, May 15, 2019 at 04:08:12PM +0300, Vladimir Davydov wrote:
> > 
> > You know I thought if we could use small/conf.h inside tarantool.
> > For this sake I prefixed symbols with TARANROOL_SMALL_ to not interfere
> > with any other symbols.
> > 
> > Another option -- provide something like
> > 
> > static const uint64_t small_features = (bitset of features);
> 
> I would define HAVE_MADV_DONTNEED in tarantool's config.h.

This won't work: you may have tarantool compiled on machine
where don't need not supported, but small compiled on a system
where madv is present (note that I'm talking about system libs,
the kernel may have own features enabled).

Also I think the main idea of "small" as a library is to separate
code as much as possible: tarantool should not do any own compile
testing but rather request the library if particular feature is
implemented (either via API or via config.h shipped with library).

Lets talk f2f.

> 
> It does compile on my box, which runs Linux. Note the cast: it should be
> fine to explicitly cast (char *) to intptr_t.

Weird, I'll retry.